feat: connect to spicedb

24 files changed, 3036 insertions, 0 deletions

diff --git a/vendor/github.com/Masterminds/squirrel/.gitignore b/vendor/github.com/Masterminds/squirrel/.gitignore
new file mode 100644
index 0000000..4a0699f
--- /dev/null
+++ b/vendor/github.com/Masterminds/squirrel/.gitignore
@@ -0,0 +1 @@
+squirrel.test
\ No newline at end of file
diff --git a/vendor/github.com/Masterminds/squirrel/.travis.yml b/vendor/github.com/Masterminds/squirrel/.travis.yml
new file mode 100644
index 0000000..7bb6da4
--- /dev/null
+++ b/vendor/github.com/Masterminds/squirrel/.travis.yml
@@ -0,0 +1,30 @@
+language: go
+
+go:
+  - 1.11.x
+  - 1.12.x
+  - 1.13.x
+
+services:
+  - mysql
+  - postgresql
+
+# Setting sudo access to false will let Travis CI use containers rather than
+# VMs to run the tests. For more details see:
+# - http://docs.travis-ci.com/user/workers/container-based-infrastructure/
+# - http://docs.travis-ci.com/user/workers/standard-infrastructure/
+sudo: false
+
+before_script:
+  - mysql -e 'CREATE DATABASE squirrel;'
+  - psql -c 'CREATE DATABASE squirrel;' -U postgres
+
+script:
+  - go test
+  - cd integration
+  - go test -args -driver sqlite3
+  - go test -args -driver mysql -dataSource travis@/squirrel
+  - go test -args -driver postgres -dataSource 'postgres://postgres@localhost/squirrel?sslmode=disable'
+
+notifications:
+  irc: "irc.freenode.net#masterminds"
diff --git a/vendor/github.com/Masterminds/squirrel/LICENSE b/vendor/github.com/Masterminds/squirrel/LICENSE
new file mode 100644
index 0000000..b459007
--- /dev/null
+++ b/vendor/github.com/Masterminds/squirrel/LICENSE
@@ -0,0 +1,23 @@
+MIT License
+
+Squirrel: The Masterminds
+Copyright (c) 2014-2015, Lann Martin. Copyright (C) 2015-2016, Google. Copyright (C) 2015, Matt Farina and Matt Butcher.
+
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/vendor/github.com/Masterminds/squirrel/README.md b/vendor/github.com/Masterminds/squirrel/README.md
new file mode 100644
index 0000000..1d37f28
--- /dev/null
+++ b/vendor/github.com/Masterminds/squirrel/README.md
@@ -0,0 +1,142 @@
+[![Stability: Maintenance](https://masterminds.github.io/stability/maintenance.svg)](https://masterminds.github.io/stability/maintenance.html)
+### Squirrel is "complete".
+Bug fixes will still be merged (slowly). Bug reports are welcome, but I will not necessarily respond to them. If another fork (or substantially similar project) actively improves on what Squirrel does, let me know and I may link to it here.
+
+
+# Squirrel - fluent SQL generator for Go
+
+```go
+import "github.com/Masterminds/squirrel"
+```
+
+
+[![GoDoc](https://godoc.org/github.com/Masterminds/squirrel?status.png)](https://godoc.org/github.com/Masterminds/squirrel)
+[![Build Status](https://api.travis-ci.org/Masterminds/squirrel.svg?branch=master)](https://travis-ci.org/Masterminds/squirrel)
+
+**Squirrel is not an ORM.** For an application of Squirrel, check out
+[structable, a table-struct mapper](https://github.com/Masterminds/structable)
+
+
+Squirrel helps you build SQL queries from composable parts:
+
+```go
+import sq "github.com/Masterminds/squirrel"
+
+users := sq.Select("*").From("users").Join("emails USING (email_id)")
+
+active := users.Where(sq.Eq{"deleted_at": nil})
+
+sql, args, err := active.ToSql()
+
+sql == "SELECT * FROM users JOIN emails USING (email_id) WHERE deleted_at IS NULL"
+```
+
+```go
+sql, args, err := sq.
+    Insert("users").Columns("name", "age").
+    Values("moe", 13).Values("larry", sq.Expr("? + 5", 12)).
+    ToSql()
+
+sql == "INSERT INTO users (name,age) VALUES (?,?),(?,? + 5)"
+```
+
+Squirrel can also execute queries directly:
+
+```go
+stooges := users.Where(sq.Eq{"username": []string{"moe", "larry", "curly", "shemp"}})
+three_stooges := stooges.Limit(3)
+rows, err := three_stooges.RunWith(db).Query()
+
+// Behaves like:
+rows, err := db.Query("SELECT * FROM users WHERE username IN (?,?,?,?) LIMIT 3",
+                      "moe", "larry", "curly", "shemp")
+```
+
+Squirrel makes conditional query building a breeze:
+
+```go
+if len(q) > 0 {
+    users = users.Where("name LIKE ?", fmt.Sprint("%", q, "%"))
+}
+```
+
+Squirrel wants to make your life easier:
+
+```go
+// StmtCache caches Prepared Stmts for you
+dbCache := sq.NewStmtCache(db)
+
+// StatementBuilder keeps your syntax neat
+mydb := sq.StatementBuilder.RunWith(dbCache)
+select_users := mydb.Select("*").From("users")
+```
+
+Squirrel loves PostgreSQL:
+
+```go
+psql := sq.StatementBuilder.PlaceholderFormat(sq.Dollar)
+
+// You use question marks for placeholders...
+sql, _, _ := psql.Select("*").From("elephants").Where("name IN (?,?)", "Dumbo", "Verna").ToSql()
+
+/// ...squirrel replaces them using PlaceholderFormat.
+sql == "SELECT * FROM elephants WHERE name IN ($1,$2)"
+
+
+/// You can retrieve id ...
+query := sq.Insert("nodes").
+    Columns("uuid", "type", "data").
+    Values(node.Uuid, node.Type, node.Data).
+    Suffix("RETURNING \"id\"").
+    RunWith(m.db).
+    PlaceholderFormat(sq.Dollar)
+
+query.QueryRow().Scan(&node.id)
+```
+
+You can escape question marks by inserting two question marks:
+
+```sql
+SELECT * FROM nodes WHERE meta->'format' ??| array[?,?]
+```
+
+will generate with the Dollar Placeholder:
+
+```sql
+SELECT * FROM nodes WHERE meta->'format' ?| array[$1,$2]
+```
+
+## FAQ
+
+* **How can I build an IN query on composite keys / tuples, e.g. `WHERE (col1, col2) IN ((1,2),(3,4))`? ([#104](https://github.com/Masterminds/squirrel/issues/104))**
+
+    Squirrel does not explicitly support tuples, but you can get the same effect with e.g.:
+
+    ```go
+    sq.Or{
+      sq.Eq{"col1": 1, "col2": 2},
+      sq.Eq{"col1": 3, "col2": 4}}
+    ```
+
+    ```sql
+    WHERE (col1 = 1 AND col2 = 2) OR (col1 = 3 AND col2 = 4)
+    ```
+
+    (which should produce the same query plan as the tuple version)
+
+* **Why doesn't `Eq{"mynumber": []uint8{1,2,3}}` turn into an `IN` query? ([#114](https://github.com/Masterminds/squirrel/issues/114))**
+
+    Values of type `[]byte` are handled specially by `database/sql`. In Go, [`byte` is just an alias of `uint8`](https://golang.org/pkg/builtin/#byte), so there is no way to distinguish `[]uint8` from `[]byte`.
+
+* **Some features are poorly documented!**
+
+    This isn't a frequent complaints section!
+
+* **Some features are poorly documented?**
+
+    Yes. The tests should be considered a part of the documentation; take a look at those for ideas on how to express more complex queries.
+
+## License
+
+Squirrel is released under the
+[MIT License](http://www.opensource.org/licenses/MIT).
diff --git a/vendor/github.com/Masterminds/squirrel/case.go b/vendor/github.com/Masterminds/squirrel/case.go
new file mode 100644
index 0000000..299e14b
--- /dev/null
+++ b/vendor/github.com/Masterminds/squirrel/case.go
@@ -0,0 +1,128 @@
+package squirrel
+
+import (
+	"bytes"
+	"errors"
+
+	"github.com/lann/builder"
+)
+
+func init() {
+	builder.Register(CaseBuilder{}, caseData{})
+}
+
+// sqlizerBuffer is a helper that allows to write many Sqlizers one by one
+// without constant checks for errors that may come from Sqlizer
+type sqlizerBuffer struct {
+	bytes.Buffer
+	args []interface{}
+	err  error
+}
+
+// WriteSql converts Sqlizer to SQL strings and writes it to buffer
+func (b *sqlizerBuffer) WriteSql(item Sqlizer) {
+	if b.err != nil {
+		return
+	}
+
+	var str string
+	var args []interface{}
+	str, args, b.err = nestedToSql(item)
+
+	if b.err != nil {
+		return
+	}
+
+	b.WriteString(str)
+	b.WriteByte(' ')
+	b.args = append(b.args, args...)
+}
+
+func (b *sqlizerBuffer) ToSql() (string, []interface{}, error) {
+	return b.String(), b.args, b.err
+}
+
+// whenPart is a helper structure to describe SQLs "WHEN ... THEN ..." expression
+type whenPart struct {
+	when Sqlizer
+	then Sqlizer
+}
+
+func newWhenPart(when interface{}, then interface{}) whenPart {
+	return whenPart{newPart(when), newPart(then)}
+}
+
+// caseData holds all the data required to build a CASE SQL construct
+type caseData struct {
+	What      Sqlizer
+	WhenParts []whenPart
+	Else      Sqlizer
+}
+
+// ToSql implements Sqlizer
+func (d *caseData) ToSql() (sqlStr string, args []interface{}, err error) {
+	if len(d.WhenParts) == 0 {
+		err = errors.New("case expression must contain at lease one WHEN clause")
+
+		return
+	}
+
+	sql := sqlizerBuffer{}
+
+	sql.WriteString("CASE ")
+	if d.What != nil {
+		sql.WriteSql(d.What)
+	}
+
+	for _, p := range d.WhenParts {
+		sql.WriteString("WHEN ")
+		sql.WriteSql(p.when)
+		sql.WriteString("THEN ")
+		sql.WriteSql(p.then)
+	}
+
+	if d.Else != nil {
+		sql.WriteString("ELSE ")
+		sql.WriteSql(d.Else)
+	}
+
+	sql.WriteString("END")
+
+	return sql.ToSql()
+}
+
+// CaseBuilder builds SQL CASE construct which could be used as parts of queries.
+type CaseBuilder builder.Builder
+
+// ToSql builds the query into a SQL string and bound args.
+func (b CaseBuilder) ToSql() (string, []interface{}, error) {
+	data := builder.GetStruct(b).(caseData)
+	return data.ToSql()
+}
+
+// MustSql builds the query into a SQL string and bound args.
+// It panics if there are any errors.
+func (b CaseBuilder) MustSql() (string, []interface{}) {
+	sql, args, err := b.ToSql()
+	if err != nil {
+		panic(err)
+	}
+	return sql, args
+}
+
+// what sets optional value for CASE construct "CASE [value] ..."
+func (b CaseBuilder) what(expr interface{}) CaseBuilder {
+	return builder.Set(b, "What", newPart(expr)).(CaseBuilder)
+}
+
+// When adds "WHEN ... THEN ..." part to CASE construct
+func (b CaseBuilder) When(when interface{}, then interface{}) CaseBuilder {
+	// TODO: performance hint: replace slice of WhenPart with just slice of parts
+	// where even indices of the slice belong to "when"s and odd indices belong to "then"s
+	return builder.Append(b, "WhenParts", newWhenPart(when, then)).(CaseBuilder)
+}
+
+// What sets optional "ELSE ..." part for CASE construct
+func (b CaseBuilder) Else(expr interface{}) CaseBuilder {
+	return builder.Set(b, "Else", newPart(expr)).(CaseBuilder)
+}
diff --git a/vendor/github.com/Masterminds/squirrel/delete.go b/vendor/github.com/Masterminds/squirrel/delete.go
new file mode 100644
index 0000000..f3f31e6
--- /dev/null
+++ b/vendor/github.com/Masterminds/squirrel/delete.go
@@ -0,0 +1,191 @@
+package squirrel
+
+import (
+	"bytes"
+	"database/sql"
+	"fmt"
+	"strings"
+
+	"github.com/lann/builder"
+)
+
+type deleteData struct {
+	PlaceholderFormat PlaceholderFormat
+	RunWith           BaseRunner
+	Prefixes          []Sqlizer
+	From              string
+	WhereParts        []Sqlizer
+	OrderBys          []string
+	Limit             string
+	Offset            string
+	Suffixes          []Sqlizer
+}
+
+func (d *deleteData) Exec() (sql.Result, error) {
+	if d.RunWith == nil {
+		return nil, RunnerNotSet
+	}
+	return ExecWith(d.RunWith, d)
+}
+
+func (d *deleteData) ToSql() (sqlStr string, args []interface{}, err error) {
+	if len(d.From) == 0 {
+		err = fmt.Errorf("delete statements must specify a From table")
+		return
+	}
+
+	sql := &bytes.Buffer{}
+
+	if len(d.Prefixes) > 0 {
+		args, err = appendToSql(d.Prefixes, sql, " ", args)
+		if err != nil {
+			return
+		}
+
+		sql.WriteString(" ")
+	}
+
+	sql.WriteString("DELETE FROM ")
+	sql.WriteString(d.From)
+
+	if len(d.WhereParts) > 0 {
+		sql.WriteString(" WHERE ")
+		args, err = appendToSql(d.WhereParts, sql, " AND ", args)
+		if err != nil {
+			return
+		}
+	}
+
+	if len(d.OrderBys) > 0 {
+		sql.WriteString(" ORDER BY ")
+		sql.WriteString(strings.Join(d.OrderBys, ", "))
+	}
+
+	if len(d.Limit) > 0 {
+		sql.WriteString(" LIMIT ")
+		sql.WriteString(d.Limit)
+	}
+
+	if len(d.Offset) > 0 {
+		sql.WriteString(" OFFSET ")
+		sql.WriteString(d.Offset)
+	}
+
+	if len(d.Suffixes) > 0 {
+		sql.WriteString(" ")
+		args, err = appendToSql(d.Suffixes, sql, " ", args)
+		if err != nil {
+			return
+		}
+	}
+
+	sqlStr, err = d.PlaceholderFormat.ReplacePlaceholders(sql.String())
+	return
+}
+
+// Builder
+
+// DeleteBuilder builds SQL DELETE statements.
+type DeleteBuilder builder.Builder
+
+func init() {
+	builder.Register(DeleteBuilder{}, deleteData{})
+}
+
+// Format methods
+
+// PlaceholderFormat sets PlaceholderFormat (e.g. Question or Dollar) for the
+// query.
+func (b DeleteBuilder) PlaceholderFormat(f PlaceholderFormat) DeleteBuilder {
+	return builder.Set(b, "PlaceholderFormat", f).(DeleteBuilder)
+}
+
+// Runner methods
+
+// RunWith sets a Runner (like database/sql.DB) to be used with e.g. Exec.
+func (b DeleteBuilder) RunWith(runner BaseRunner) DeleteBuilder {
+	return setRunWith(b, runner).(DeleteBuilder)
+}
+
+// Exec builds and Execs the query with the Runner set by RunWith.
+func (b DeleteBuilder) Exec() (sql.Result, error) {
+	data := builder.GetStruct(b).(deleteData)
+	return data.Exec()
+}
+
+// SQL methods
+
+// ToSql builds the query into a SQL string and bound args.
+func (b DeleteBuilder) ToSql() (string, []interface{}, error) {
+	data := builder.GetStruct(b).(deleteData)
+	return data.ToSql()
+}
+
+// MustSql builds the query into a SQL string and bound args.
+// It panics if there are any errors.
+func (b DeleteBuilder) MustSql() (string, []interface{}) {
+	sql, args, err := b.ToSql()
+	if err != nil {
+		panic(err)
+	}
+	return sql, args
+}
+
+// Prefix adds an expression to the beginning of the query
+func (b DeleteBuilder) Prefix(sql string, args ...interface{}) DeleteBuilder {
+	return b.PrefixExpr(Expr(sql, args...))
+}
+
+// PrefixExpr adds an expression to the very beginning of the query
+func (b DeleteBuilder) PrefixExpr(expr Sqlizer) DeleteBuilder {
+	return builder.Append(b, "Prefixes", expr).(DeleteBuilder)
+}
+
+// From sets the table to be deleted from.
+func (b DeleteBuilder) From(from string) DeleteBuilder {
+	return builder.Set(b, "From", from).(DeleteBuilder)
+}
+
+// Where adds WHERE expressions to the query.
+//
+// See SelectBuilder.Where for more information.
+func (b DeleteBuilder) Where(pred interface{}, args ...interface{}) DeleteBuilder {
+	return builder.Append(b, "WhereParts", newWherePart(pred, args...)).(DeleteBuilder)
+}
+
+// OrderBy adds ORDER BY expressions to the query.
+func (b DeleteBuilder) OrderBy(orderBys ...string) DeleteBuilder {
+	return builder.Extend(b, "OrderBys", orderBys).(DeleteBuilder)
+}
+
+// Limit sets a LIMIT clause on the query.
+func (b DeleteBuilder) Limit(limit uint64) DeleteBuilder {
+	return builder.Set(b, "Limit", fmt.Sprintf("%d", limit)).(DeleteBuilder)
+}
+
+// Offset sets a OFFSET clause on the query.
+func (b DeleteBuilder) Offset(offset uint64) DeleteBuilder {
+	return builder.Set(b, "Offset", fmt.Sprintf("%d", offset)).(DeleteBuilder)
+}
+
+// Suffix adds an expression to the end of the query
+func (b DeleteBuilder) Suffix(sql string, args ...interface{}) DeleteBuilder {
+	return b.SuffixExpr(Expr(sql, args...))
+}
+
+// SuffixExpr adds an expression to the end of the query
+func (b DeleteBuilder) SuffixExpr(expr Sqlizer) DeleteBuilder {
+	return builder.Append(b, "Suffixes", expr).(DeleteBuilder)
+}
+
+func (b DeleteBuilder) Query() (*sql.Rows, error) {
+	data := builder.GetStruct(b).(deleteData)
+	return data.Query()
+}
+
+func (d *deleteData) Query() (*sql.Rows, error) {
+	if d.RunWith == nil {
+		return nil, RunnerNotSet
+	}
+	return QueryWith(d.RunWith, d)
+}
diff --git a/vendor/github.com/Masterminds/squirrel/delete_ctx.go b/vendor/github.com/Masterminds/squirrel/delete_ctx.go
new file mode 100644
index 0000000..de83c55
--- /dev/null
+++ b/vendor/github.com/Masterminds/squirrel/delete_ctx.go
@@ -0,0 +1,69 @@
+// +build go1.8
+
+package squirrel
+
+import (
+	"context"
+	"database/sql"
+
+	"github.com/lann/builder"
+)
+
+func (d *deleteData) ExecContext(ctx context.Context) (sql.Result, error) {
+	if d.RunWith == nil {
+		return nil, RunnerNotSet
+	}
+	ctxRunner, ok := d.RunWith.(ExecerContext)
+	if !ok {
+		return nil, NoContextSupport
+	}
+	return ExecContextWith(ctx, ctxRunner, d)
+}
+
+func (d *deleteData) QueryContext(ctx context.Context) (*sql.Rows, error) {
+	if d.RunWith == nil {
+		return nil, RunnerNotSet
+	}
+	ctxRunner, ok := d.RunWith.(QueryerContext)
+	if !ok {
+		return nil, NoContextSupport
+	}
+	return QueryContextWith(ctx, ctxRunner, d)
+}
+
+func (d *deleteData) QueryRowContext(ctx context.Context) RowScanner {
+	if d.RunWith == nil {
+		return &Row{err: RunnerNotSet}
+	}
+	queryRower, ok := d.RunWith.(QueryRowerContext)
+	if !ok {
+		if _, ok := d.RunWith.(QueryerContext); !ok {
+			return &Row{err: RunnerNotQueryRunner}
+		}
+		return &Row{err: NoContextSupport}
+	}
+	return QueryRowContextWith(ctx, queryRower, d)
+}
+
+// ExecContext builds and ExecContexts the query with the Runner set by RunWith.
+func (b DeleteBuilder) ExecContext(ctx context.Context) (sql.Result, error) {
+	data := builder.GetStruct(b).(deleteData)
+	return data.ExecContext(ctx)
+}
+
+// QueryContext builds and QueryContexts the query with the Runner set by RunWith.
+func (b DeleteBuilder) QueryContext(ctx context.Context) (*sql.Rows, error) {
+	data := builder.GetStruct(b).(deleteData)
+	return data.QueryContext(ctx)
+}
+
+// QueryRowContext builds and QueryRowContexts the query with the Runner set by RunWith.
+func (b DeleteBuilder) QueryRowContext(ctx context.Context) RowScanner {
+	data := builder.GetStruct(b).(deleteData)
+	return data.QueryRowContext(ctx)
+}
+
+// ScanContext is a shortcut for QueryRowContext().Scan.
+func (b DeleteBuilder) ScanContext(ctx context.Context, dest ...interface{}) error {
+	return b.QueryRowContext(ctx).Scan(dest...)
+}
diff --git a/vendor/github.com/Masterminds/squirrel/expr.go b/vendor/github.com/Masterminds/squirrel/expr.go
new file mode 100644
index 0000000..eba1b45
--- /dev/null
+++ b/vendor/github.com/Masterminds/squirrel/expr.go
@@ -0,0 +1,419 @@
+package squirrel
+
+import (
+	"bytes"
+	"database/sql/driver"
+	"fmt"
+	"reflect"
+	"sort"
+	"strings"
+)
+
+const (
+	// Portable true/false literals.
+	sqlTrue  = "(1=1)"
+	sqlFalse = "(1=0)"
+)
+
+type expr struct {
+	sql  string
+	args []interface{}
+}
+
+// Expr builds an expression from a SQL fragment and arguments.
+//
+// Ex:
+//     Expr("FROM_UNIXTIME(?)", t)
+func Expr(sql string, args ...interface{}) Sqlizer {
+	return expr{sql: sql, args: args}
+}
+
+func (e expr) ToSql() (sql string, args []interface{}, err error) {
+	simple := true
+	for _, arg := range e.args {
+		if _, ok := arg.(Sqlizer); ok {
+			simple = false
+		}
+	}
+	if simple {
+		return e.sql, e.args, nil
+	}
+
+	buf := &bytes.Buffer{}
+	ap := e.args
+	sp := e.sql
+
+	var isql string
+	var iargs []interface{}
+
+	for err == nil && len(ap) > 0 && len(sp) > 0 {
+		i := strings.Index(sp, "?")
+		if i < 0 {
+			// no more placeholders
+			break
+		}
+		if len(sp) > i+1 && sp[i+1:i+2] == "?" {
+			// escaped "??"; append it and step past
+			buf.WriteString(sp[:i+2])
+			sp = sp[i+2:]
+			continue
+		}
+
+		if as, ok := ap[0].(Sqlizer); ok {
+			// sqlizer argument; expand it and append the result
+			isql, iargs, err = as.ToSql()
+			buf.WriteString(sp[:i])
+			buf.WriteString(isql)
+			args = append(args, iargs...)
+		} else {
+			// normal argument; append it and the placeholder
+			buf.WriteString(sp[:i+1])
+			args = append(args, ap[0])
+		}
+
+		// step past the argument and placeholder
+		ap = ap[1:]
+		sp = sp[i+1:]
+	}
+
+	// append the remaining sql and arguments
+	buf.WriteString(sp)
+	return buf.String(), append(args, ap...), err
+}
+
+type concatExpr []interface{}
+
+func (ce concatExpr) ToSql() (sql string, args []interface{}, err error) {
+	for _, part := range ce {
+		switch p := part.(type) {
+		case string:
+			sql += p
+		case Sqlizer:
+			pSql, pArgs, err := p.ToSql()
+			if err != nil {
+				return "", nil, err
+			}
+			sql += pSql
+			args = append(args, pArgs...)
+		default:
+			return "", nil, fmt.Errorf("%#v is not a string or Sqlizer", part)
+		}
+	}
+	return
+}
+
+// ConcatExpr builds an expression by concatenating strings and other expressions.
+//
+// Ex:
+//     name_expr := Expr("CONCAT(?, ' ', ?)", firstName, lastName)
+//     ConcatExpr("COALESCE(full_name,", name_expr, ")")
+func ConcatExpr(parts ...interface{}) concatExpr {
+	return concatExpr(parts)
+}
+
+// aliasExpr helps to alias part of SQL query generated with underlying "expr"
+type aliasExpr struct {
+	expr  Sqlizer
+	alias string
+}
+
+// Alias allows to define alias for column in SelectBuilder. Useful when column is
+// defined as complex expression like IF or CASE
+// Ex:
+//		.Column(Alias(caseStmt, "case_column"))
+func Alias(expr Sqlizer, alias string) aliasExpr {
+	return aliasExpr{expr, alias}
+}
+
+func (e aliasExpr) ToSql() (sql string, args []interface{}, err error) {
+	sql, args, err = e.expr.ToSql()
+	if err == nil {
+		sql = fmt.Sprintf("(%s) AS %s", sql, e.alias)
+	}
+	return
+}
+
+// Eq is syntactic sugar for use with Where/Having/Set methods.
+type Eq map[string]interface{}
+
+func (eq Eq) toSQL(useNotOpr bool) (sql string, args []interface{}, err error) {
+	if len(eq) == 0 {
+		// Empty Sql{} evaluates to true.
+		sql = sqlTrue
+		return
+	}
+
+	var (
+		exprs       []string
+		equalOpr    = "="
+		inOpr       = "IN"
+		nullOpr     = "IS"
+		inEmptyExpr = sqlFalse
+	)
+
+	if useNotOpr {
+		equalOpr = "<>"
+		inOpr = "NOT IN"
+		nullOpr = "IS NOT"
+		inEmptyExpr = sqlTrue
+	}
+
+	sortedKeys := getSortedKeys(eq)
+	for _, key := range sortedKeys {
+		var expr string
+		val := eq[key]
+
+		switch v := val.(type) {
+		case driver.Valuer:
+			if val, err = v.Value(); err != nil {
+				return
+			}
+		}
+
+		r := reflect.ValueOf(val)
+		if r.Kind() == reflect.Ptr {
+			if r.IsNil() {
+				val = nil
+			} else {
+				val = r.Elem().Interface()
+			}
+		}
+
+		if val == nil {
+			expr = fmt.Sprintf("%s %s NULL", key, nullOpr)
+		} else {
+			if isListType(val) {
+				valVal := reflect.ValueOf(val)
+				if valVal.Len() == 0 {
+					expr = inEmptyExpr
+					if args == nil {
+						args = []interface{}{}
+					}
+				} else {
+					for i := 0; i < valVal.Len(); i++ {
+						args = append(args, valVal.Index(i).Interface())
+					}
+					expr = fmt.Sprintf("%s %s (%s)", key, inOpr, Placeholders(valVal.Len()))
+				}
+			} else {
+				expr = fmt.Sprintf("%s %s ?", key, equalOpr)
+				args = append(args, val)
+			}
+		}
+		exprs = append(exprs, expr)
+	}
+	sql = strings.Join(exprs, " AND ")
+	return
+}
+
+func (eq Eq) ToSql() (sql string, args []interface{}, err error) {
+	return eq.toSQL(false)
+}
+
+// NotEq is syntactic sugar for use with Where/Having/Set methods.
+// Ex:
+//     .Where(NotEq{"id": 1}) == "id <> 1"
+type NotEq Eq
+
+func (neq NotEq) ToSql() (sql string, args []interface{}, err error) {
+	return Eq(neq).toSQL(true)
+}
+
+// Like is syntactic sugar for use with LIKE conditions.
+// Ex:
+//     .Where(Like{"name": "%irrel"})
+type Like map[string]interface{}
+
+func (lk Like) toSql(opr string) (sql string, args []interface{}, err error) {
+	var exprs []string
+	for key, val := range lk {
+		expr := ""
+
+		switch v := val.(type) {
+		case driver.Valuer:
+			if val, err = v.Value(); err != nil {
+				return
+			}
+		}
+
+		if val == nil {
+			err = fmt.Errorf("cannot use null with like operators")
+			return
+		} else {
+			if isListType(val) {
+				err = fmt.Errorf("cannot use array or slice with like operators")
+				return
+			} else {
+				expr = fmt.Sprintf("%s %s ?", key, opr)
+				args = append(args, val)
+			}
+		}
+		exprs = append(exprs, expr)
+	}
+	sql = strings.Join(exprs, " AND ")
+	return
+}
+
+func (lk Like) ToSql() (sql string, args []interface{}, err error) {
+	return lk.toSql("LIKE")
+}
+
+// NotLike is syntactic sugar for use with LIKE conditions.
+// Ex:
+//     .Where(NotLike{"name": "%irrel"})
+type NotLike Like
+
+func (nlk NotLike) ToSql() (sql string, args []interface{}, err error) {
+	return Like(nlk).toSql("NOT LIKE")
+}
+
+// ILike is syntactic sugar for use with ILIKE conditions.
+// Ex:
+//    .Where(ILike{"name": "sq%"})
+type ILike Like
+
+func (ilk ILike) ToSql() (sql string, args []interface{}, err error) {
+	return Like(ilk).toSql("ILIKE")
+}
+
+// NotILike is syntactic sugar for use with ILIKE conditions.
+// Ex:
+//    .Where(NotILike{"name": "sq%"})
+type NotILike Like
+
+func (nilk NotILike) ToSql() (sql string, args []interface{}, err error) {
+	return Like(nilk).toSql("NOT ILIKE")
+}
+
+// Lt is syntactic sugar for use with Where/Having/Set methods.
+// Ex:
+//     .Where(Lt{"id": 1})
+type Lt map[string]interface{}
+
+func (lt Lt) toSql(opposite, orEq bool) (sql string, args []interface{}, err error) {
+	var (
+		exprs []string
+		opr   = "<"
+	)
+
+	if opposite {
+		opr = ">"
+	}
+
+	if orEq {
+		opr = fmt.Sprintf("%s%s", opr, "=")
+	}
+
+	sortedKeys := getSortedKeys(lt)
+	for _, key := range sortedKeys {
+		var expr string
+		val := lt[key]
+
+		switch v := val.(type) {
+		case driver.Valuer:
+			if val, err = v.Value(); err != nil {
+				return
+			}
+		}
+
+		if val == nil {
+			err = fmt.Errorf("cannot use null with less than or greater than operators")
+			return
+		}
+		if isListType(val) {
+			err = fmt.Errorf("cannot use array or slice with less than or greater than operators")
+			return
+		}
+		expr = fmt.Sprintf("%s %s ?", key, opr)
+		args = append(args, val)
+
+		exprs = append(exprs, expr)
+	}
+	sql = strings.Join(exprs, " AND ")
+	return
+}
+
+func (lt Lt) ToSql() (sql string, args []interface{}, err error) {
+	return lt.toSql(false, false)
+}
+
+// LtOrEq is syntactic sugar for use with Where/Having/Set methods.
+// Ex:
+//     .Where(LtOrEq{"id": 1}) == "id <= 1"
+type LtOrEq Lt
+
+func (ltOrEq LtOrEq) ToSql() (sql string, args []interface{}, err error) {
+	return Lt(ltOrEq).toSql(false, true)
+}
+
+// Gt is syntactic sugar for use with Where/Having/Set methods.
+// Ex:
+//     .Where(Gt{"id": 1}) == "id > 1"
+type Gt Lt
+
+func (gt Gt) ToSql() (sql string, args []interface{}, err error) {
+	return Lt(gt).toSql(true, false)
+}
+
+// GtOrEq is syntactic sugar for use with Where/Having/Set methods.
+// Ex:
+//     .Where(GtOrEq{"id": 1}) == "id >= 1"
+type GtOrEq Lt
+
+func (gtOrEq GtOrEq) ToSql() (sql string, args []interface{}, err error) {
+	return Lt(gtOrEq).toSql(true, true)
+}
+
+type conj []Sqlizer
+
+func (c conj) join(sep, defaultExpr string) (sql string, args []interface{}, err error) {
+	if len(c) == 0 {
+		return defaultExpr, []interface{}{}, nil
+	}
+	var sqlParts []string
+	for _, sqlizer := range c {
+		partSQL, partArgs, err := nestedToSql(sqlizer)
+		if err != nil {
+			return "", nil, err
+		}
+		if partSQL != "" {
+			sqlParts = append(sqlParts, partSQL)
+			args = append(args, partArgs...)
+		}
+	}
+	if len(sqlParts) > 0 {
+		sql = fmt.Sprintf("(%s)", strings.Join(sqlParts, sep))
+	}
+	return
+}
+
+// And conjunction Sqlizers
+type And conj
+
+func (a And) ToSql() (string, []interface{}, error) {
+	return conj(a).join(" AND ", sqlTrue)
+}
+
+// Or conjunction Sqlizers
+type Or conj
+
+func (o Or) ToSql() (string, []interface{}, error) {
+	return conj(o).join(" OR ", sqlFalse)
+}
+
+func getSortedKeys(exp map[string]interface{}) []string {
+	sortedKeys := make([]string, 0, len(exp))
+	for k := range exp {
+		sortedKeys = append(sortedKeys, k)
+	}
+	sort.Strings(sortedKeys)
+	return sortedKeys
+}
+
+func isListType(val interface{}) bool {
+	if driver.IsValue(val) {
+		return false
+	}
+	valVal := reflect.ValueOf(val)
+	return valVal.Kind() == reflect.Array || valVal.Kind() == reflect.Slice
+}
diff --git a/vendor/github.com/Masterminds/squirrel/insert.go b/vendor/github.com/Masterminds/squirrel/insert.go
new file mode 100644
index 0000000..c23a579
--- /dev/null
+++ b/vendor/github.com/Masterminds/squirrel/insert.go
@@ -0,0 +1,298 @@
+package squirrel
+
+import (
+	"bytes"
+	"database/sql"
+	"errors"
+	"fmt"
+	"io"
+	"sort"
+	"strings"
+
+	"github.com/lann/builder"
+)
+
+type insertData struct {
+	PlaceholderFormat PlaceholderFormat
+	RunWith           BaseRunner
+	Prefixes          []Sqlizer
+	StatementKeyword  string
+	Options           []string
+	Into              string
+	Columns           []string
+	Values            [][]interface{}
+	Suffixes          []Sqlizer
+	Select            *SelectBuilder
+}
+
+func (d *insertData) Exec() (sql.Result, error) {
+	if d.RunWith == nil {
+		return nil, RunnerNotSet
+	}
+	return ExecWith(d.RunWith, d)
+}
+
+func (d *insertData) Query() (*sql.Rows, error) {
+	if d.RunWith == nil {
+		return nil, RunnerNotSet
+	}
+	return QueryWith(d.RunWith, d)
+}
+
+func (d *insertData) QueryRow() RowScanner {
+	if d.RunWith == nil {
+		return &Row{err: RunnerNotSet}
+	}
+	queryRower, ok := d.RunWith.(QueryRower)
+	if !ok {
+		return &Row{err: RunnerNotQueryRunner}
+	}
+	return QueryRowWith(queryRower, d)
+}
+
+func (d *insertData) ToSql() (sqlStr string, args []interface{}, err error) {
+	if len(d.Into) == 0 {
+		err = errors.New("insert statements must specify a table")
+		return
+	}
+	if len(d.Values) == 0 && d.Select == nil {
+		err = errors.New("insert statements must have at least one set of values or select clause")
+		return
+	}
+
+	sql := &bytes.Buffer{}
+
+	if len(d.Prefixes) > 0 {
+		args, err = appendToSql(d.Prefixes, sql, " ", args)
+		if err != nil {
+			return
+		}
+
+		sql.WriteString(" ")
+	}
+
+	if d.StatementKeyword == "" {
+		sql.WriteString("INSERT ")
+	} else {
+		sql.WriteString(d.StatementKeyword)
+		sql.WriteString(" ")
+	}
+
+	if len(d.Options) > 0 {
+		sql.WriteString(strings.Join(d.Options, " "))
+		sql.WriteString(" ")
+	}
+
+	sql.WriteString("INTO ")
+	sql.WriteString(d.Into)
+	sql.WriteString(" ")
+
+	if len(d.Columns) > 0 {
+		sql.WriteString("(")
+		sql.WriteString(strings.Join(d.Columns, ","))
+		sql.WriteString(") ")
+	}
+
+	if d.Select != nil {
+		args, err = d.appendSelectToSQL(sql, args)
+	} else {
+		args, err = d.appendValuesToSQL(sql, args)
+	}
+	if err != nil {
+		return
+	}
+
+	if len(d.Suffixes) > 0 {
+		sql.WriteString(" ")
+		args, err = appendToSql(d.Suffixes, sql, " ", args)
+		if err != nil {
+			return
+		}
+	}
+
+	sqlStr, err = d.PlaceholderFormat.ReplacePlaceholders(sql.String())
+	return
+}
+
+func (d *insertData) appendValuesToSQL(w io.Writer, args []interface{}) ([]interface{}, error) {
+	if len(d.Values) == 0 {
+		return args, errors.New("values for insert statements are not set")
+	}
+
+	io.WriteString(w, "VALUES ")
+
+	valuesStrings := make([]string, len(d.Values))
+	for r, row := range d.Values {
+		valueStrings := make([]string, len(row))
+		for v, val := range row {
+			if vs, ok := val.(Sqlizer); ok {
+				vsql, vargs, err := vs.ToSql()
+				if err != nil {
+					return nil, err
+				}
+				valueStrings[v] = vsql
+				args = append(args, vargs...)
+			} else {
+				valueStrings[v] = "?"
+				args = append(args, val)
+			}
+		}
+		valuesStrings[r] = fmt.Sprintf("(%s)", strings.Join(valueStrings, ","))
+	}
+
+	io.WriteString(w, strings.Join(valuesStrings, ","))
+
+	return args, nil
+}
+
+func (d *insertData) appendSelectToSQL(w io.Writer, args []interface{}) ([]interface{}, error) {
+	if d.Select == nil {
+		return args, errors.New("select clause for insert statements are not set")
+	}
+
+	selectClause, sArgs, err := d.Select.ToSql()
+	if err != nil {
+		return args, err
+	}
+
+	io.WriteString(w, selectClause)
+	args = append(args, sArgs...)
+
+	return args, nil
+}
+
+// Builder
+
+// InsertBuilder builds SQL INSERT statements.
+type InsertBuilder builder.Builder
+
+func init() {
+	builder.Register(InsertBuilder{}, insertData{})
+}
+
+// Format methods
+
+// PlaceholderFormat sets PlaceholderFormat (e.g. Question or Dollar) for the
+// query.
+func (b InsertBuilder) PlaceholderFormat(f PlaceholderFormat) InsertBuilder {
+	return builder.Set(b, "PlaceholderFormat", f).(InsertBuilder)
+}
+
+// Runner methods
+
+// RunWith sets a Runner (like database/sql.DB) to be used with e.g. Exec.
+func (b InsertBuilder) RunWith(runner BaseRunner) InsertBuilder {
+	return setRunWith(b, runner).(InsertBuilder)
+}
+
+// Exec builds and Execs the query with the Runner set by RunWith.
+func (b InsertBuilder) Exec() (sql.Result, error) {
+	data := builder.GetStruct(b).(insertData)
+	return data.Exec()
+}
+
+// Query builds and Querys the query with the Runner set by RunWith.
+func (b InsertBuilder) Query() (*sql.Rows, error) {
+	data := builder.GetStruct(b).(insertData)
+	return data.Query()
+}
+
+// QueryRow builds and QueryRows the query with the Runner set by RunWith.
+func (b InsertBuilder) QueryRow() RowScanner {
+	data := builder.GetStruct(b).(insertData)
+	return data.QueryRow()
+}
+
+// Scan is a shortcut for QueryRow().Scan.
+func (b InsertBuilder) Scan(dest ...interface{}) error {
+	return b.QueryRow().Scan(dest...)
+}
+
+// SQL methods
+
+// ToSql builds the query into a SQL string and bound args.
+func (b InsertBuilder) ToSql() (string, []interface{}, error) {
+	data := builder.GetStruct(b).(insertData)
+	return data.ToSql()
+}
+
+// MustSql builds the query into a SQL string and bound args.
+// It panics if there are any errors.
+func (b InsertBuilder) MustSql() (string, []interface{}) {
+	sql, args, err := b.ToSql()
+	if err != nil {
+		panic(err)
+	}
+	return sql, args
+}
+
+// Prefix adds an expression to the beginning of the query
+func (b InsertBuilder) Prefix(sql string, args ...interface{}) InsertBuilder {
+	return b.PrefixExpr(Expr(sql, args...))
+}
+
+// PrefixExpr adds an expression to the very beginning of the query
+func (b InsertBuilder) PrefixExpr(expr Sqlizer) InsertBuilder {
+	return builder.Append(b, "Prefixes", expr).(InsertBuilder)
+}
+
+// Options adds keyword options before the INTO clause of the query.
+func (b InsertBuilder) Options(options ...string) InsertBuilder {
+	return builder.Extend(b, "Options", options).(InsertBuilder)
+}
+
+// Into sets the INTO clause of the query.
+func (b InsertBuilder) Into(from string) InsertBuilder {
+	return builder.Set(b, "Into", from).(InsertBuilder)
+}
+
+// Columns adds insert columns to the query.
+func (b InsertBuilder) Columns(columns ...string) InsertBuilder {
+	return builder.Extend(b, "Columns", columns).(InsertBuilder)
+}
+
+// Values adds a single row's values to the query.
+func (b InsertBuilder) Values(values ...interface{}) InsertBuilder {
+	return builder.Append(b, "Values", values).(InsertBuilder)
+}
+
+// Suffix adds an expression to the end of the query
+func (b InsertBuilder) Suffix(sql string, args ...interface{}) InsertBuilder {
+	return b.SuffixExpr(Expr(sql, args...))
+}
+
+// SuffixExpr adds an expression to the end of the query
+func (b InsertBuilder) SuffixExpr(expr Sqlizer) InsertBuilder {
+	return builder.Append(b, "Suffixes", expr).(InsertBuilder)
+}
+
+// SetMap set columns and values for insert builder from a map of column name and value
+// note that it will reset all previous columns and values was set if any
+func (b InsertBuilder) SetMap(clauses map[string]interface{}) InsertBuilder {
+	// Keep the columns in a consistent order by sorting the column key string.
+	cols := make([]string, 0, len(clauses))
+	for col := range clauses {
+		cols = append(cols, col)
+	}
+	sort.Strings(cols)
+
+	vals := make([]interface{}, 0, len(clauses))
+	for _, col := range cols {
+		vals = append(vals, clauses[col])
+	}
+
+	b = builder.Set(b, "Columns", cols).(InsertBuilder)
+	b = builder.Set(b, "Values", [][]interface{}{vals}).(InsertBuilder)
+
+	return b
+}
+
+// Select set Select clause for insert query
+// If Values and Select are used, then Select has higher priority
+func (b InsertBuilder) Select(sb SelectBuilder) InsertBuilder {
+	return builder.Set(b, "Select", &sb).(InsertBuilder)
+}
+
+func (b InsertBuilder) statementKeyword(keyword string) InsertBuilder {
+	return builder.Set(b, "StatementKeyword", keyword).(InsertBuilder)
+}
diff --git a/vendor/github.com/Masterminds/squirrel/insert_ctx.go b/vendor/github.com/Masterminds/squirrel/insert_ctx.go
new file mode 100644
index 0000000..4541c2f
--- /dev/null
+++ b/vendor/github.com/Masterminds/squirrel/insert_ctx.go
@@ -0,0 +1,69 @@
+// +build go1.8
+
+package squirrel
+
+import (
+	"context"
+	"database/sql"
+
+	"github.com/lann/builder"
+)
+
+func (d *insertData) ExecContext(ctx context.Context) (sql.Result, error) {
+	if d.RunWith == nil {
+		return nil, RunnerNotSet
+	}
+	ctxRunner, ok := d.RunWith.(ExecerContext)
+	if !ok {
+		return nil, NoContextSupport
+	}
+	return ExecContextWith(ctx, ctxRunner, d)
+}
+
+func (d *insertData) QueryContext(ctx context.Context) (*sql.Rows, error) {
+	if d.RunWith == nil {
+		return nil, RunnerNotSet
+	}
+	ctxRunner, ok := d.RunWith.(QueryerContext)
+	if !ok {
+		return nil, NoContextSupport
+	}
+	return QueryContextWith(ctx, ctxRunner, d)
+}
+
+func (d *insertData) QueryRowContext(ctx context.Context) RowScanner {
+	if d.RunWith == nil {
+		return &Row{err: RunnerNotSet}
+	}
+	queryRower, ok := d.RunWith.(QueryRowerContext)
+	if !ok {
+		if _, ok := d.RunWith.(QueryerContext); !ok {
+			return &Row{err: RunnerNotQueryRunner}
+		}
+		return &Row{err: NoContextSupport}
+	}
+	return QueryRowContextWith(ctx, queryRower, d)
+}
+
+// ExecContext builds and ExecContexts the query with the Runner set by RunWith.
+func (b InsertBuilder) ExecContext(ctx context.Context) (sql.Result, error) {
+	data := builder.GetStruct(b).(insertData)
+	return data.ExecContext(ctx)
+}
+
+// QueryContext builds and QueryContexts the query with the Runner set by RunWith.
+func (b InsertBuilder) QueryContext(ctx context.Context) (*sql.Rows, error) {
+	data := builder.GetStruct(b).(insertData)
+	return data.QueryContext(ctx)
+}
+
+// QueryRowContext builds and QueryRowContexts the query with the Runner set by RunWith.
+func (b InsertBuilder) QueryRowContext(ctx context.Context) RowScanner {
+	data := builder.GetStruct(b).(insertData)
+	return data.QueryRowContext(ctx)
+}
+
+// ScanContext is a shortcut for QueryRowContext().Scan.
+func (b InsertBuilder) ScanContext(ctx context.Context, dest ...interface{}) error {
+	return b.QueryRowContext(ctx).Scan(dest...)
+}
diff --git a/vendor/github.com/Masterminds/squirrel/part.go b/vendor/github.com/Masterminds/squirrel/part.go
new file mode 100644
index 0000000..c58f68f
--- /dev/null
+++ b/vendor/github.com/Masterminds/squirrel/part.go
@@ -0,0 +1,63 @@
+package squirrel
+
+import (
+	"fmt"
+	"io"
+)
+
+type part struct {
+	pred interface{}
+	args []interface{}
+}
+
+func newPart(pred interface{}, args ...interface{}) Sqlizer {
+	return &part{pred, args}
+}
+
+func (p part) ToSql() (sql string, args []interface{}, err error) {
+	switch pred := p.pred.(type) {
+	case nil:
+		// no-op
+	case Sqlizer:
+		sql, args, err = nestedToSql(pred)
+	case string:
+		sql = pred
+		args = p.args
+	default:
+		err = fmt.Errorf("expected string or Sqlizer, not %T", pred)
+	}
+	return
+}
+
+func nestedToSql(s Sqlizer) (string, []interface{}, error) {
+	if raw, ok := s.(rawSqlizer); ok {
+		return raw.toSqlRaw()
+	} else {
+		return s.ToSql()
+	}
+}
+
+func appendToSql(parts []Sqlizer, w io.Writer, sep string, args []interface{}) ([]interface{}, error) {
+	for i, p := range parts {
+		partSql, partArgs, err := nestedToSql(p)
+		if err != nil {
+			return nil, err
+		} else if len(partSql) == 0 {
+			continue
+		}
+
+		if i > 0 {
+			_, err := io.WriteString(w, sep)
+			if err != nil {
+				return nil, err
+			}
+		}
+
+		_, err = io.WriteString(w, partSql)
+		if err != nil {
+			return nil, err
+		}
+		args = append(args, partArgs...)
+	}
+	return args, nil
+}
diff --git a/vendor/github.com/Masterminds/squirrel/placeholder.go b/vendor/github.com/Masterminds/squirrel/placeholder.go
new file mode 100644
index 0000000..8e97a6c
--- /dev/null
+++ b/vendor/github.com/Masterminds/squirrel/placeholder.go
@@ -0,0 +1,114 @@
+package squirrel
+
+import (
+	"bytes"
+	"fmt"
+	"strings"
+)
+
+// PlaceholderFormat is the interface that wraps the ReplacePlaceholders method.
+//
+// ReplacePlaceholders takes a SQL statement and replaces each question mark
+// placeholder with a (possibly different) SQL placeholder.
+type PlaceholderFormat interface {
+	ReplacePlaceholders(sql string) (string, error)
+}
+
+type placeholderDebugger interface {
+	debugPlaceholder() string
+}
+
+var (
+	// Question is a PlaceholderFormat instance that leaves placeholders as
+	// question marks.
+	Question = questionFormat{}
+
+	// Dollar is a PlaceholderFormat instance that replaces placeholders with
+	// dollar-prefixed positional placeholders (e.g. $1, $2, $3).
+	Dollar = dollarFormat{}
+
+	// Colon is a PlaceholderFormat instance that replaces placeholders with
+	// colon-prefixed positional placeholders (e.g. :1, :2, :3).
+	Colon = colonFormat{}
+
+	// AtP is a PlaceholderFormat instance that replaces placeholders with
+	// "@p"-prefixed positional placeholders (e.g. @p1, @p2, @p3).
+	AtP = atpFormat{}
+)
+
+type questionFormat struct{}
+
+func (questionFormat) ReplacePlaceholders(sql string) (string, error) {
+	return sql, nil
+}
+
+func (questionFormat) debugPlaceholder() string {
+	return "?"
+}
+
+type dollarFormat struct{}
+
+func (dollarFormat) ReplacePlaceholders(sql string) (string, error) {
+	return replacePositionalPlaceholders(sql, "$")
+}
+
+func (dollarFormat) debugPlaceholder() string {
+	return "$"
+}
+
+type colonFormat struct{}
+
+func (colonFormat) ReplacePlaceholders(sql string) (string, error) {
+	return replacePositionalPlaceholders(sql, ":")
+}
+
+func (colonFormat) debugPlaceholder() string {
+	return ":"
+}
+
+type atpFormat struct{}
+
+func (atpFormat) ReplacePlaceholders(sql string) (string, error) {
+	return replacePositionalPlaceholders(sql, "@p")
+}
+
+func (atpFormat) debugPlaceholder() string {
+	return "@p"
+}
+
+// Placeholders returns a string with count ? placeholders joined with commas.
+func Placeholders(count int) string {
+	if count < 1 {
+		return ""
+	}
+
+	return strings.Repeat(",?", count)[1:]
+}
+
+func replacePositionalPlaceholders(sql, prefix string) (string, error) {
+	buf := &bytes.Buffer{}
+	i := 0
+	for {
+		p := strings.Index(sql, "?")
+		if p == -1 {
+			break
+		}
+
+		if len(sql[p:]) > 1 && sql[p:p+2] == "??" { // escape ?? => ?
+			buf.WriteString(sql[:p])
+			buf.WriteString("?")
+			if len(sql[p:]) == 1 {
+				break
+			}
+			sql = sql[p+2:]
+		} else {
+			i++
+			buf.WriteString(sql[:p])
+			fmt.Fprintf(buf, "%s%d", prefix, i)
+			sql = sql[p+1:]
+		}
+	}
+
+	buf.WriteString(sql)
+	return buf.String(), nil
+}
diff --git a/vendor/github.com/Masterminds/squirrel/row.go b/vendor/github.com/Masterminds/squirrel/row.go
new file mode 100644
index 0000000..74ffda9
--- /dev/null
+++ b/vendor/github.com/Masterminds/squirrel/row.go
@@ -0,0 +1,22 @@
+package squirrel
+
+// RowScanner is the interface that wraps the Scan method.
+//
+// Scan behaves like database/sql.Row.Scan.
+type RowScanner interface {
+	Scan(...interface{}) error
+}
+
+// Row wraps database/sql.Row to let squirrel return new errors on Scan.
+type Row struct {
+	RowScanner
+	err error
+}
+
+// Scan returns Row.err or calls RowScanner.Scan.
+func (r *Row) Scan(dest ...interface{}) error {
+	if r.err != nil {
+		return r.err
+	}
+	return r.RowScanner.Scan(dest...)
+}
diff --git a/vendor/github.com/Masterminds/squirrel/select.go b/vendor/github.com/Masterminds/squirrel/select.go
new file mode 100644
index 0000000..d55ce4c
--- /dev/null
+++ b/vendor/github.com/Masterminds/squirrel/select.go
@@ -0,0 +1,403 @@
+package squirrel
+
+import (
+	"bytes"
+	"database/sql"
+	"fmt"
+	"strings"
+
+	"github.com/lann/builder"
+)
+
+type selectData struct {
+	PlaceholderFormat PlaceholderFormat
+	RunWith           BaseRunner
+	Prefixes          []Sqlizer
+	Options           []string
+	Columns           []Sqlizer
+	From              Sqlizer
+	Joins             []Sqlizer
+	WhereParts        []Sqlizer
+	GroupBys          []string
+	HavingParts       []Sqlizer
+	OrderByParts      []Sqlizer
+	Limit             string
+	Offset            string
+	Suffixes          []Sqlizer
+}
+
+func (d *selectData) Exec() (sql.Result, error) {
+	if d.RunWith == nil {
+		return nil, RunnerNotSet
+	}
+	return ExecWith(d.RunWith, d)
+}
+
+func (d *selectData) Query() (*sql.Rows, error) {
+	if d.RunWith == nil {
+		return nil, RunnerNotSet
+	}
+	return QueryWith(d.RunWith, d)
+}
+
+func (d *selectData) QueryRow() RowScanner {
+	if d.RunWith == nil {
+		return &Row{err: RunnerNotSet}
+	}
+	queryRower, ok := d.RunWith.(QueryRower)
+	if !ok {
+		return &Row{err: RunnerNotQueryRunner}
+	}
+	return QueryRowWith(queryRower, d)
+}
+
+func (d *selectData) ToSql() (sqlStr string, args []interface{}, err error) {
+	sqlStr, args, err = d.toSqlRaw()
+	if err != nil {
+		return
+	}
+
+	sqlStr, err = d.PlaceholderFormat.ReplacePlaceholders(sqlStr)
+	return
+}
+
+func (d *selectData) toSqlRaw() (sqlStr string, args []interface{}, err error) {
+	if len(d.Columns) == 0 {
+		err = fmt.Errorf("select statements must have at least one result column")
+		return
+	}
+
+	sql := &bytes.Buffer{}
+
+	if len(d.Prefixes) > 0 {
+		args, err = appendToSql(d.Prefixes, sql, " ", args)
+		if err != nil {
+			return
+		}
+
+		sql.WriteString(" ")
+	}
+
+	sql.WriteString("SELECT ")
+
+	if len(d.Options) > 0 {
+		sql.WriteString(strings.Join(d.Options, " "))
+		sql.WriteString(" ")
+	}
+
+	if len(d.Columns) > 0 {
+		args, err = appendToSql(d.Columns, sql, ", ", args)
+		if err != nil {
+			return
+		}
+	}
+
+	if d.From != nil {
+		sql.WriteString(" FROM ")
+		args, err = appendToSql([]Sqlizer{d.From}, sql, "", args)
+		if err != nil {
+			return
+		}
+	}
+
+	if len(d.Joins) > 0 {
+		sql.WriteString(" ")
+		args, err = appendToSql(d.Joins, sql, " ", args)
+		if err != nil {
+			return
+		}
+	}
+
+	if len(d.WhereParts) > 0 {
+		sql.WriteString(" WHERE ")
+		args, err = appendToSql(d.WhereParts, sql, " AND ", args)
+		if err != nil {
+			return
+		}
+	}
+
+	if len(d.GroupBys) > 0 {
+		sql.WriteString(" GROUP BY ")
+		sql.WriteString(strings.Join(d.GroupBys, ", "))
+	}
+
+	if len(d.HavingParts) > 0 {
+		sql.WriteString(" HAVING ")
+		args, err = appendToSql(d.HavingParts, sql, " AND ", args)
+		if err != nil {
+			return
+		}
+	}
+
+	if len(d.OrderByParts) > 0 {
+		sql.WriteString(" ORDER BY ")
+		args, err = appendToSql(d.OrderByParts, sql, ", ", args)
+		if err != nil {
+			return
+		}
+	}
+
+	if len(d.Limit) > 0 {
+		sql.WriteString(" LIMIT ")
+		sql.WriteString(d.Limit)
+	}
+
+	if len(d.Offset) > 0 {
+		sql.WriteString(" OFFSET ")
+		sql.WriteString(d.Offset)
+	}
+
+	if len(d.Suffixes) > 0 {
+		sql.WriteString(" ")
+
+		args, err = appendToSql(d.Suffixes, sql, " ", args)
+		if err != nil {
+			return
+		}
+	}
+
+	sqlStr = sql.String()
+	return
+}
+
+// Builder
+
+// SelectBuilder builds SQL SELECT statements.
+type SelectBuilder builder.Builder
+
+func init() {
+	builder.Register(SelectBuilder{}, selectData{})
+}
+
+// Format methods
+
+// PlaceholderFormat sets PlaceholderFormat (e.g. Question or Dollar) for the
+// query.
+func (b SelectBuilder) PlaceholderFormat(f PlaceholderFormat) SelectBuilder {
+	return builder.Set(b, "PlaceholderFormat", f).(SelectBuilder)
+}
+
+// Runner methods
+
+// RunWith sets a Runner (like database/sql.DB) to be used with e.g. Exec.
+// For most cases runner will be a database connection.
+//
+// Internally we use this to mock out the database connection for testing.
+func (b SelectBuilder) RunWith(runner BaseRunner) SelectBuilder {
+	return setRunWith(b, runner).(SelectBuilder)
+}
+
+// Exec builds and Execs the query with the Runner set by RunWith.
+func (b SelectBuilder) Exec() (sql.Result, error) {
+	data := builder.GetStruct(b).(selectData)
+	return data.Exec()
+}
+
+// Query builds and Querys the query with the Runner set by RunWith.
+func (b SelectBuilder) Query() (*sql.Rows, error) {
+	data := builder.GetStruct(b).(selectData)
+	return data.Query()
+}
+
+// QueryRow builds and QueryRows the query with the Runner set by RunWith.
+func (b SelectBuilder) QueryRow() RowScanner {
+	data := builder.GetStruct(b).(selectData)
+	return data.QueryRow()
+}
+
+// Scan is a shortcut for QueryRow().Scan.
+func (b SelectBuilder) Scan(dest ...interface{}) error {
+	return b.QueryRow().Scan(dest...)
+}
+
+// SQL methods
+
+// ToSql builds the query into a SQL string and bound args.
+func (b SelectBuilder) ToSql() (string, []interface{}, error) {
+	data := builder.GetStruct(b).(selectData)
+	return data.ToSql()
+}
+
+func (b SelectBuilder) toSqlRaw() (string, []interface{}, error) {
+	data := builder.GetStruct(b).(selectData)
+	return data.toSqlRaw()
+}
+
+// MustSql builds the query into a SQL string and bound args.
+// It panics if there are any errors.
+func (b SelectBuilder) MustSql() (string, []interface{}) {
+	sql, args, err := b.ToSql()
+	if err != nil {
+		panic(err)
+	}
+	return sql, args
+}
+
+// Prefix adds an expression to the beginning of the query
+func (b SelectBuilder) Prefix(sql string, args ...interface{}) SelectBuilder {
+	return b.PrefixExpr(Expr(sql, args...))
+}
+
+// PrefixExpr adds an expression to the very beginning of the query
+func (b SelectBuilder) PrefixExpr(expr Sqlizer) SelectBuilder {
+	return builder.Append(b, "Prefixes", expr).(SelectBuilder)
+}
+
+// Distinct adds a DISTINCT clause to the query.
+func (b SelectBuilder) Distinct() SelectBuilder {
+	return b.Options("DISTINCT")
+}
+
+// Options adds select option to the query
+func (b SelectBuilder) Options(options ...string) SelectBuilder {
+	return builder.Extend(b, "Options", options).(SelectBuilder)
+}
+
+// Columns adds result columns to the query.
+func (b SelectBuilder) Columns(columns ...string) SelectBuilder {
+	parts := make([]interface{}, 0, len(columns))
+	for _, str := range columns {
+		parts = append(parts, newPart(str))
+	}
+	return builder.Extend(b, "Columns", parts).(SelectBuilder)
+}
+
+// RemoveColumns remove all columns from query.
+// Must add a new column with Column or Columns methods, otherwise
+// return a error.
+func (b SelectBuilder) RemoveColumns() SelectBuilder {
+	return builder.Delete(b, "Columns").(SelectBuilder)
+}
+
+// Column adds a result column to the query.
+// Unlike Columns, Column accepts args which will be bound to placeholders in
+// the columns string, for example:
+//   Column("IF(col IN ("+squirrel.Placeholders(3)+"), 1, 0) as col", 1, 2, 3)
+func (b SelectBuilder) Column(column interface{}, args ...interface{}) SelectBuilder {
+	return builder.Append(b, "Columns", newPart(column, args...)).(SelectBuilder)
+}
+
+// From sets the FROM clause of the query.
+func (b SelectBuilder) From(from string) SelectBuilder {
+	return builder.Set(b, "From", newPart(from)).(SelectBuilder)
+}
+
+// FromSelect sets a subquery into the FROM clause of the query.
+func (b SelectBuilder) FromSelect(from SelectBuilder, alias string) SelectBuilder {
+	// Prevent misnumbered parameters in nested selects (#183).
+	from = from.PlaceholderFormat(Question)
+	return builder.Set(b, "From", Alias(from, alias)).(SelectBuilder)
+}
+
+// JoinClause adds a join clause to the query.
+func (b SelectBuilder) JoinClause(pred interface{}, args ...interface{}) SelectBuilder {
+	return builder.Append(b, "Joins", newPart(pred, args...)).(SelectBuilder)
+}
+
+// Join adds a JOIN clause to the query.
+func (b SelectBuilder) Join(join string, rest ...interface{}) SelectBuilder {
+	return b.JoinClause("JOIN "+join, rest...)
+}
+
+// LeftJoin adds a LEFT JOIN clause to the query.
+func (b SelectBuilder) LeftJoin(join string, rest ...interface{}) SelectBuilder {
+	return b.JoinClause("LEFT JOIN "+join, rest...)
+}
+
+// RightJoin adds a RIGHT JOIN clause to the query.
+func (b SelectBuilder) RightJoin(join string, rest ...interface{}) SelectBuilder {
+	return b.JoinClause("RIGHT JOIN "+join, rest...)
+}
+
+// InnerJoin adds a INNER JOIN clause to the query.
+func (b SelectBuilder) InnerJoin(join string, rest ...interface{}) SelectBuilder {
+	return b.JoinClause("INNER JOIN "+join, rest...)
+}
+
+// CrossJoin adds a CROSS JOIN clause to the query.
+func (b SelectBuilder) CrossJoin(join string, rest ...interface{}) SelectBuilder {
+	return b.JoinClause("CROSS JOIN "+join, rest...)
+}
+
+// Where adds an expression to the WHERE clause of the query.
+//
+// Expressions are ANDed together in the generated SQL.
+//
+// Where accepts several types for its pred argument:
+//
+// nil OR "" - ignored.
+//
+// string - SQL expression.
+// If the expression has SQL placeholders then a set of arguments must be passed
+// as well, one for each placeholder.
+//
+// map[string]interface{} OR Eq - map of SQL expressions to values. Each key is
+// transformed into an expression like "<key> = ?", with the corresponding value
+// bound to the placeholder. If the value is nil, the expression will be "<key>
+// IS NULL". If the value is an array or slice, the expression will be "<key> IN
+// (?,?,...)", with one placeholder for each item in the value. These expressions
+// are ANDed together.
+//
+// Where will panic if pred isn't any of the above types.
+func (b SelectBuilder) Where(pred interface{}, args ...interface{}) SelectBuilder {
+	if pred == nil || pred == "" {
+		return b
+	}
+	return builder.Append(b, "WhereParts", newWherePart(pred, args...)).(SelectBuilder)
+}
+
+// GroupBy adds GROUP BY expressions to the query.
+func (b SelectBuilder) GroupBy(groupBys ...string) SelectBuilder {
+	return builder.Extend(b, "GroupBys", groupBys).(SelectBuilder)
+}
+
+// Having adds an expression to the HAVING clause of the query.
+//
+// See Where.
+func (b SelectBuilder) Having(pred interface{}, rest ...interface{}) SelectBuilder {
+	return builder.Append(b, "HavingParts", newWherePart(pred, rest...)).(SelectBuilder)
+}
+
+// OrderByClause adds ORDER BY clause to the query.
+func (b SelectBuilder) OrderByClause(pred interface{}, args ...interface{}) SelectBuilder {
+	return builder.Append(b, "OrderByParts", newPart(pred, args...)).(SelectBuilder)
+}
+
+// OrderBy adds ORDER BY expressions to the query.
+func (b SelectBuilder) OrderBy(orderBys ...string) SelectBuilder {
+	for _, orderBy := range orderBys {
+		b = b.OrderByClause(orderBy)
+	}
+
+	return b
+}
+
+// Limit sets a LIMIT clause on the query.
+func (b SelectBuilder) Limit(limit uint64) SelectBuilder {
+	return builder.Set(b, "Limit", fmt.Sprintf("%d", limit)).(SelectBuilder)
+}
+
+// Limit ALL allows to access all records with limit
+func (b SelectBuilder) RemoveLimit() SelectBuilder {
+	return builder.Delete(b, "Limit").(SelectBuilder)
+}
+
+// Offset sets a OFFSET clause on the query.
+func (b SelectBuilder) Offset(offset uint64) SelectBuilder {
+	return builder.Set(b, "Offset", fmt.Sprintf("%d", offset)).(SelectBuilder)
+}
+
+// RemoveOffset removes OFFSET clause.
+func (b SelectBuilder) RemoveOffset() SelectBuilder {
+	return builder.Delete(b, "Offset").(SelectBuilder)
+}
+
+// Suffix adds an expression to the end of the query
+func (b SelectBuilder) Suffix(sql string, args ...interface{}) SelectBuilder {
+	return b.SuffixExpr(Expr(sql, args...))
+}
+
+// SuffixExpr adds an expression to the end of the query
+func (b SelectBuilder) SuffixExpr(expr Sqlizer) SelectBuilder {
+	return builder.Append(b, "Suffixes", expr).(SelectBuilder)
+}
diff --git a/vendor/github.com/Masterminds/squirrel/select_ctx.go b/vendor/github.com/Masterminds/squirrel/select_ctx.go
new file mode 100644
index 0000000..4c42c13
--- /dev/null
+++ b/vendor/github.com/Masterminds/squirrel/select_ctx.go
@@ -0,0 +1,69 @@
+// +build go1.8
+
+package squirrel
+
+import (
+	"context"
+	"database/sql"
+
+	"github.com/lann/builder"
+)
+
+func (d *selectData) ExecContext(ctx context.Context) (sql.Result, error) {
+	if d.RunWith == nil {
+		return nil, RunnerNotSet
+	}
+	ctxRunner, ok := d.RunWith.(ExecerContext)
+	if !ok {
+		return nil, NoContextSupport
+	}
+	return ExecContextWith(ctx, ctxRunner, d)
+}
+
+func (d *selectData) QueryContext(ctx context.Context) (*sql.Rows, error) {
+	if d.RunWith == nil {
+		return nil, RunnerNotSet
+	}
+	ctxRunner, ok := d.RunWith.(QueryerContext)
+	if !ok {
+		return nil, NoContextSupport
+	}
+	return QueryContextWith(ctx, ctxRunner, d)
+}
+
+func (d *selectData) QueryRowContext(ctx context.Context) RowScanner {
+	if d.RunWith == nil {
+		return &Row{err: RunnerNotSet}
+	}
+	queryRower, ok := d.RunWith.(QueryRowerContext)
+	if !ok {
+		if _, ok := d.RunWith.(QueryerContext); !ok {
+			return &Row{err: RunnerNotQueryRunner}
+		}
+		return &Row{err: NoContextSupport}
+	}
+	return QueryRowContextWith(ctx, queryRower, d)
+}
+
+// ExecContext builds and ExecContexts the query with the Runner set by RunWith.
+func (b SelectBuilder) ExecContext(ctx context.Context) (sql.Result, error) {
+	data := builder.GetStruct(b).(selectData)
+	return data.ExecContext(ctx)
+}
+
+// QueryContext builds and QueryContexts the query with the Runner set by RunWith.
+func (b SelectBuilder) QueryContext(ctx context.Context) (*sql.Rows, error) {
+	data := builder.GetStruct(b).(selectData)
+	return data.QueryContext(ctx)
+}
+
+// QueryRowContext builds and QueryRowContexts the query with the Runner set by RunWith.
+func (b SelectBuilder) QueryRowContext(ctx context.Context) RowScanner {
+	data := builder.GetStruct(b).(selectData)
+	return data.QueryRowContext(ctx)
+}
+
+// ScanContext is a shortcut for QueryRowContext().Scan.
+func (b SelectBuilder) ScanContext(ctx context.Context, dest ...interface{}) error {
+	return b.QueryRowContext(ctx).Scan(dest...)
+}
diff --git a/vendor/github.com/Masterminds/squirrel/squirrel.go b/vendor/github.com/Masterminds/squirrel/squirrel.go
new file mode 100644
index 0000000..46d456e
--- /dev/null
+++ b/vendor/github.com/Masterminds/squirrel/squirrel.go
@@ -0,0 +1,183 @@
+// Package squirrel provides a fluent SQL generator.
+//
+// See https://github.com/Masterminds/squirrel for examples.
+package squirrel
+
+import (
+	"bytes"
+	"database/sql"
+	"fmt"
+	"strings"
+
+	"github.com/lann/builder"
+)
+
+// Sqlizer is the interface that wraps the ToSql method.
+//
+// ToSql returns a SQL representation of the Sqlizer, along with a slice of args
+// as passed to e.g. database/sql.Exec. It can also return an error.
+type Sqlizer interface {
+	ToSql() (string, []interface{}, error)
+}
+
+// rawSqlizer is expected to do what Sqlizer does, but without finalizing placeholders.
+// This is useful for nested queries.
+type rawSqlizer interface {
+	toSqlRaw() (string, []interface{}, error)
+}
+
+// Execer is the interface that wraps the Exec method.
+//
+// Exec executes the given query as implemented by database/sql.Exec.
+type Execer interface {
+	Exec(query string, args ...interface{}) (sql.Result, error)
+}
+
+// Queryer is the interface that wraps the Query method.
+//
+// Query executes the given query as implemented by database/sql.Query.
+type Queryer interface {
+	Query(query string, args ...interface{}) (*sql.Rows, error)
+}
+
+// QueryRower is the interface that wraps the QueryRow method.
+//
+// QueryRow executes the given query as implemented by database/sql.QueryRow.
+type QueryRower interface {
+	QueryRow(query string, args ...interface{}) RowScanner
+}
+
+// BaseRunner groups the Execer and Queryer interfaces.
+type BaseRunner interface {
+	Execer
+	Queryer
+}
+
+// Runner groups the Execer, Queryer, and QueryRower interfaces.
+type Runner interface {
+	Execer
+	Queryer
+	QueryRower
+}
+
+// WrapStdSql wraps a type implementing the standard SQL interface with methods that
+// squirrel expects.
+func WrapStdSql(stdSql StdSql) Runner {
+	return &stdsqlRunner{stdSql}
+}
+
+// StdSql encompasses the standard methods of the *sql.DB type, and other types that
+// wrap these methods.
+type StdSql interface {
+	Query(string, ...interface{}) (*sql.Rows, error)
+	QueryRow(string, ...interface{}) *sql.Row
+	Exec(string, ...interface{}) (sql.Result, error)
+}
+
+type stdsqlRunner struct {
+	StdSql
+}
+
+func (r *stdsqlRunner) QueryRow(query string, args ...interface{}) RowScanner {
+	return r.StdSql.QueryRow(query, args...)
+}
+
+func setRunWith(b interface{}, runner BaseRunner) interface{} {
+	switch r := runner.(type) {
+	case StdSqlCtx:
+		runner = WrapStdSqlCtx(r)
+	case StdSql:
+		runner = WrapStdSql(r)
+	}
+	return builder.Set(b, "RunWith", runner)
+}
+
+// RunnerNotSet is returned by methods that need a Runner if it isn't set.
+var RunnerNotSet = fmt.Errorf("cannot run; no Runner set (RunWith)")
+
+// RunnerNotQueryRunner is returned by QueryRow if the RunWith value doesn't implement QueryRower.
+var RunnerNotQueryRunner = fmt.Errorf("cannot QueryRow; Runner is not a QueryRower")
+
+// ExecWith Execs the SQL returned by s with db.
+func ExecWith(db Execer, s Sqlizer) (res sql.Result, err error) {
+	query, args, err := s.ToSql()
+	if err != nil {
+		return
+	}
+	return db.Exec(query, args...)
+}
+
+// QueryWith Querys the SQL returned by s with db.
+func QueryWith(db Queryer, s Sqlizer) (rows *sql.Rows, err error) {
+	query, args, err := s.ToSql()
+	if err != nil {
+		return
+	}
+	return db.Query(query, args...)
+}
+
+// QueryRowWith QueryRows the SQL returned by s with db.
+func QueryRowWith(db QueryRower, s Sqlizer) RowScanner {
+	query, args, err := s.ToSql()
+	return &Row{RowScanner: db.QueryRow(query, args...), err: err}
+}
+
+// DebugSqlizer calls ToSql on s and shows the approximate SQL to be executed
+//
+// If ToSql returns an error, the result of this method will look like:
+// "[ToSql error: %s]" or "[DebugSqlizer error: %s]"
+//
+// IMPORTANT: As its name suggests, this function should only be used for
+// debugging. While the string result *might* be valid SQL, this function does
+// not try very hard to ensure it. Additionally, executing the output of this
+// function with any untrusted user input is certainly insecure.
+func DebugSqlizer(s Sqlizer) string {
+	sql, args, err := s.ToSql()
+	if err != nil {
+		return fmt.Sprintf("[ToSql error: %s]", err)
+	}
+
+	var placeholder string
+	downCast, ok := s.(placeholderDebugger)
+	if !ok {
+		placeholder = "?"
+	} else {
+		placeholder = downCast.debugPlaceholder()
+	}
+	// TODO: dedupe this with placeholder.go
+	buf := &bytes.Buffer{}
+	i := 0
+	for {
+		p := strings.Index(sql, placeholder)
+		if p == -1 {
+			break
+		}
+		if len(sql[p:]) > 1 && sql[p:p+2] == "??" { // escape ?? => ?
+			buf.WriteString(sql[:p])
+			buf.WriteString("?")
+			if len(sql[p:]) == 1 {
+				break
+			}
+			sql = sql[p+2:]
+		} else {
+			if i+1 > len(args) {
+				return fmt.Sprintf(
+					"[DebugSqlizer error: too many placeholders in %#v for %d args]",
+					sql, len(args))
+			}
+			buf.WriteString(sql[:p])
+			fmt.Fprintf(buf, "'%v'", args[i])
+			// advance our sql string "cursor" beyond the arg we placed
+			sql = sql[p+1:]
+			i++
+		}
+	}
+	if i < len(args) {
+		return fmt.Sprintf(
+			"[DebugSqlizer error: not enough placeholders in %#v for %d args]",
+			sql, len(args))
+	}
+	// "append" any remaning sql that won't need interpolating
+	buf.WriteString(sql)
+	return buf.String()
+}
diff --git a/vendor/github.com/Masterminds/squirrel/squirrel_ctx.go b/vendor/github.com/Masterminds/squirrel/squirrel_ctx.go
new file mode 100644
index 0000000..c20148a
--- /dev/null
+++ b/vendor/github.com/Masterminds/squirrel/squirrel_ctx.go
@@ -0,0 +1,93 @@
+// +build go1.8
+
+package squirrel
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+)
+
+// NoContextSupport is returned if a db doesn't support Context.
+var NoContextSupport = errors.New("DB does not support Context")
+
+// ExecerContext is the interface that wraps the ExecContext method.
+//
+// Exec executes the given query as implemented by database/sql.ExecContext.
+type ExecerContext interface {
+	ExecContext(ctx context.Context, query string, args ...interface{}) (sql.Result, error)
+}
+
+// QueryerContext is the interface that wraps the QueryContext method.
+//
+// QueryContext executes the given query as implemented by database/sql.QueryContext.
+type QueryerContext interface {
+	QueryContext(ctx context.Context, query string, args ...interface{}) (*sql.Rows, error)
+}
+
+// QueryRowerContext is the interface that wraps the QueryRowContext method.
+//
+// QueryRowContext executes the given query as implemented by database/sql.QueryRowContext.
+type QueryRowerContext interface {
+	QueryRowContext(ctx context.Context, query string, args ...interface{}) RowScanner
+}
+
+// RunnerContext groups the Runner interface, along with the Context versions of each of
+// its methods
+type RunnerContext interface {
+	Runner
+	QueryerContext
+	QueryRowerContext
+	ExecerContext
+}
+
+// WrapStdSqlCtx wraps a type implementing the standard SQL interface plus the context
+// versions of the methods with methods that squirrel expects.
+func WrapStdSqlCtx(stdSqlCtx StdSqlCtx) RunnerContext {
+	return &stdsqlCtxRunner{stdSqlCtx}
+}
+
+// StdSqlCtx encompasses the standard methods of the *sql.DB type, along with the Context
+// versions of those methods, and other types that wrap these methods.
+type StdSqlCtx interface {
+	StdSql
+	QueryContext(context.Context, string, ...interface{}) (*sql.Rows, error)
+	QueryRowContext(context.Context, string, ...interface{}) *sql.Row
+	ExecContext(context.Context, string, ...interface{}) (sql.Result, error)
+}
+
+type stdsqlCtxRunner struct {
+	StdSqlCtx
+}
+
+func (r *stdsqlCtxRunner) QueryRow(query string, args ...interface{}) RowScanner {
+	return r.StdSqlCtx.QueryRow(query, args...)
+}
+
+func (r *stdsqlCtxRunner) QueryRowContext(ctx context.Context, query string, args ...interface{}) RowScanner {
+	return r.StdSqlCtx.QueryRowContext(ctx, query, args...)
+}
+
+// ExecContextWith ExecContexts the SQL returned by s with db.
+func ExecContextWith(ctx context.Context, db ExecerContext, s Sqlizer) (res sql.Result, err error) {
+	query, args, err := s.ToSql()
+	if err != nil {
+		return
+	}
+	return db.ExecContext(ctx, query, args...)
+}
+
+// QueryContextWith QueryContexts the SQL returned by s with db.
+func QueryContextWith(ctx context.Context, db QueryerContext, s Sqlizer) (rows *sql.Rows, err error) {
+	query, args, err := s.ToSql()
+	if err != nil {
+		return
+	}
+	return db.QueryContext(ctx, query, args...)
+}
+
+// QueryRowContextWith QueryRowContexts the SQL returned by s with db.
+func QueryRowContextWith(ctx context.Context, db QueryRowerContext, s Sqlizer) RowScanner {
+	query, args, err := s.ToSql()
+	return &Row{RowScanner: db.QueryRowContext(ctx, query, args...), err: err}
+}
diff --git a/vendor/github.com/Masterminds/squirrel/statement.go b/vendor/github.com/Masterminds/squirrel/statement.go
new file mode 100644
index 0000000..9420c67
--- /dev/null
+++ b/vendor/github.com/Masterminds/squirrel/statement.go
@@ -0,0 +1,104 @@
+package squirrel
+
+import "github.com/lann/builder"
+
+// StatementBuilderType is the type of StatementBuilder.
+type StatementBuilderType builder.Builder
+
+// Select returns a SelectBuilder for this StatementBuilderType.
+func (b StatementBuilderType) Select(columns ...string) SelectBuilder {
+	return SelectBuilder(b).Columns(columns...)
+}
+
+// Insert returns a InsertBuilder for this StatementBuilderType.
+func (b StatementBuilderType) Insert(into string) InsertBuilder {
+	return InsertBuilder(b).Into(into)
+}
+
+// Replace returns a InsertBuilder for this StatementBuilderType with the
+// statement keyword set to "REPLACE".
+func (b StatementBuilderType) Replace(into string) InsertBuilder {
+	return InsertBuilder(b).statementKeyword("REPLACE").Into(into)
+}
+
+// Update returns a UpdateBuilder for this StatementBuilderType.
+func (b StatementBuilderType) Update(table string) UpdateBuilder {
+	return UpdateBuilder(b).Table(table)
+}
+
+// Delete returns a DeleteBuilder for this StatementBuilderType.
+func (b StatementBuilderType) Delete(from string) DeleteBuilder {
+	return DeleteBuilder(b).From(from)
+}
+
+// PlaceholderFormat sets the PlaceholderFormat field for any child builders.
+func (b StatementBuilderType) PlaceholderFormat(f PlaceholderFormat) StatementBuilderType {
+	return builder.Set(b, "PlaceholderFormat", f).(StatementBuilderType)
+}
+
+// RunWith sets the RunWith field for any child builders.
+func (b StatementBuilderType) RunWith(runner BaseRunner) StatementBuilderType {
+	return setRunWith(b, runner).(StatementBuilderType)
+}
+
+// Where adds WHERE expressions to the query.
+//
+// See SelectBuilder.Where for more information.
+func (b StatementBuilderType) Where(pred interface{}, args ...interface{}) StatementBuilderType {
+	return builder.Append(b, "WhereParts", newWherePart(pred, args...)).(StatementBuilderType)
+}
+
+// StatementBuilder is a parent builder for other builders, e.g. SelectBuilder.
+var StatementBuilder = StatementBuilderType(builder.EmptyBuilder).PlaceholderFormat(Question)
+
+// Select returns a new SelectBuilder, optionally setting some result columns.
+//
+// See SelectBuilder.Columns.
+func Select(columns ...string) SelectBuilder {
+	return StatementBuilder.Select(columns...)
+}
+
+// Insert returns a new InsertBuilder with the given table name.
+//
+// See InsertBuilder.Into.
+func Insert(into string) InsertBuilder {
+	return StatementBuilder.Insert(into)
+}
+
+// Replace returns a new InsertBuilder with the statement keyword set to
+// "REPLACE" and with the given table name.
+//
+// See InsertBuilder.Into.
+func Replace(into string) InsertBuilder {
+	return StatementBuilder.Replace(into)
+}
+
+// Update returns a new UpdateBuilder with the given table name.
+//
+// See UpdateBuilder.Table.
+func Update(table string) UpdateBuilder {
+	return StatementBuilder.Update(table)
+}
+
+// Delete returns a new DeleteBuilder with the given table name.
+//
+// See DeleteBuilder.Table.
+func Delete(from string) DeleteBuilder {
+	return StatementBuilder.Delete(from)
+}
+
+// Case returns a new CaseBuilder
+// "what" represents case value
+func Case(what ...interface{}) CaseBuilder {
+	b := CaseBuilder(builder.EmptyBuilder)
+
+	switch len(what) {
+	case 0:
+	case 1:
+		b = b.what(what[0])
+	default:
+		b = b.what(newPart(what[0], what[1:]...))
+
+	}
+	return b
+}
diff --git a/vendor/github.com/Masterminds/squirrel/stmtcacher.go b/vendor/github.com/Masterminds/squirrel/stmtcacher.go
new file mode 100644
index 0000000..5bf267a
--- /dev/null
+++ b/vendor/github.com/Masterminds/squirrel/stmtcacher.go
@@ -0,0 +1,121 @@
+package squirrel
+
+import (
+	"database/sql"
+	"fmt"
+	"sync"
+)
+
+// Prepareer is the interface that wraps the Prepare method.
+//
+// Prepare executes the given query as implemented by database/sql.Prepare.
+type Preparer interface {
+	Prepare(query string) (*sql.Stmt, error)
+}
+
+// DBProxy groups the Execer, Queryer, QueryRower, and Preparer interfaces.
+type DBProxy interface {
+	Execer
+	Queryer
+	QueryRower
+	Preparer
+}
+
+// NOTE: NewStmtCache is defined in stmtcacher_ctx.go (Go >= 1.8) or stmtcacher_noctx.go (Go < 1.8).
+
+// StmtCache wraps and delegates down to a Preparer type
+//
+// It also automatically prepares all statements sent to the underlying Preparer calls
+// for Exec, Query and QueryRow and caches the returns *sql.Stmt using the provided
+// query as the key. So that it can be automatically re-used.
+type StmtCache struct {
+	prep  Preparer
+	cache map[string]*sql.Stmt
+	mu    sync.Mutex
+}
+
+// Prepare delegates down to the underlying Preparer and caches the result
+// using the provided query as a key
+func (sc *StmtCache) Prepare(query string) (*sql.Stmt, error) {
+	sc.mu.Lock()
+	defer sc.mu.Unlock()
+
+	stmt, ok := sc.cache[query]
+	if ok {
+		return stmt, nil
+	}
+	stmt, err := sc.prep.Prepare(query)
+	if err == nil {
+		sc.cache[query] = stmt
+	}
+	return stmt, err
+}
+
+// Exec delegates down to the underlying Preparer using a prepared statement
+func (sc *StmtCache) Exec(query string, args ...interface{}) (res sql.Result, err error) {
+	stmt, err := sc.Prepare(query)
+	if err != nil {
+		return
+	}
+	return stmt.Exec(args...)
+}
+
+// Query delegates down to the underlying Preparer using a prepared statement
+func (sc *StmtCache) Query(query string, args ...interface{}) (rows *sql.Rows, err error) {
+	stmt, err := sc.Prepare(query)
+	if err != nil {
+		return
+	}
+	return stmt.Query(args...)
+}
+
+// QueryRow delegates down to the underlying Preparer using a prepared statement
+func (sc *StmtCache) QueryRow(query string, args ...interface{}) RowScanner {
+	stmt, err := sc.Prepare(query)
+	if err != nil {
+		return &Row{err: err}
+	}
+	return stmt.QueryRow(args...)
+}
+
+// Clear removes and closes all the currently cached prepared statements
+func (sc *StmtCache) Clear() (err error) {
+	sc.mu.Lock()
+	defer sc.mu.Unlock()
+
+	for key, stmt := range sc.cache {
+		delete(sc.cache, key)
+
+		if stmt == nil {
+			continue
+		}
+
+		if cerr := stmt.Close(); cerr != nil {
+			err = cerr
+		}
+	}
+
+	if err != nil {
+		return fmt.Errorf("one or more Stmt.Close failed; last error: %v", err)
+	}
+
+	return
+}
+
+type DBProxyBeginner interface {
+	DBProxy
+	Begin() (*sql.Tx, error)
+}
+
+type stmtCacheProxy struct {
+	DBProxy
+	db *sql.DB
+}
+
+func NewStmtCacheProxy(db *sql.DB) DBProxyBeginner {
+	return &stmtCacheProxy{DBProxy: NewStmtCache(db), db: db}
+}
+
+func (sp *stmtCacheProxy) Begin() (*sql.Tx, error) {
+	return sp.db.Begin()
+}
diff --git a/vendor/github.com/Masterminds/squirrel/stmtcacher_ctx.go b/vendor/github.com/Masterminds/squirrel/stmtcacher_ctx.go
new file mode 100644
index 0000000..53603cf
--- /dev/null
+++ b/vendor/github.com/Masterminds/squirrel/stmtcacher_ctx.go
@@ -0,0 +1,86 @@
+// +build go1.8
+
+package squirrel
+
+import (
+	"context"
+	"database/sql"
+)
+
+// PrepareerContext is the interface that wraps the Prepare and PrepareContext methods.
+//
+// Prepare executes the given query as implemented by database/sql.Prepare.
+// PrepareContext executes the given query as implemented by database/sql.PrepareContext.
+type PreparerContext interface {
+	Preparer
+	PrepareContext(ctx context.Context, query string) (*sql.Stmt, error)
+}
+
+// DBProxyContext groups the Execer, Queryer, QueryRower and PreparerContext interfaces.
+type DBProxyContext interface {
+	Execer
+	Queryer
+	QueryRower
+	PreparerContext
+}
+
+// NewStmtCache returns a *StmtCache wrapping a PreparerContext that caches Prepared Stmts.
+//
+// Stmts are cached based on the string value of their queries.
+func NewStmtCache(prep PreparerContext) *StmtCache {
+	return &StmtCache{prep: prep, cache: make(map[string]*sql.Stmt)}
+}
+
+// NewStmtCacher is deprecated
+//
+// Use NewStmtCache instead
+func NewStmtCacher(prep PreparerContext) DBProxyContext {
+	return NewStmtCache(prep)
+}
+
+// PrepareContext delegates down to the underlying PreparerContext and caches the result
+// using the provided query as a key
+func (sc *StmtCache) PrepareContext(ctx context.Context, query string) (*sql.Stmt, error) {
+	ctxPrep, ok := sc.prep.(PreparerContext)
+	if !ok {
+		return nil, NoContextSupport
+	}
+	sc.mu.Lock()
+	defer sc.mu.Unlock()
+	stmt, ok := sc.cache[query]
+	if ok {
+		return stmt, nil
+	}
+	stmt, err := ctxPrep.PrepareContext(ctx, query)
+	if err == nil {
+		sc.cache[query] = stmt
+	}
+	return stmt, err
+}
+
+// ExecContext delegates down to the underlying PreparerContext using a prepared statement
+func (sc *StmtCache) ExecContext(ctx context.Context, query string, args ...interface{}) (res sql.Result, err error) {
+	stmt, err := sc.PrepareContext(ctx, query)
+	if err != nil {
+		return
+	}
+	return stmt.ExecContext(ctx, args...)
+}
+
+// QueryContext delegates down to the underlying PreparerContext using a prepared statement
+func (sc *StmtCache) QueryContext(ctx context.Context, query string, args ...interface{}) (rows *sql.Rows, err error) {
+	stmt, err := sc.PrepareContext(ctx, query)
+	if err != nil {
+		return
+	}
+	return stmt.QueryContext(ctx, args...)
+}
+
+// QueryRowContext delegates down to the underlying PreparerContext using a prepared statement
+func (sc *StmtCache) QueryRowContext(ctx context.Context, query string, args ...interface{}) RowScanner {
+	stmt, err := sc.PrepareContext(ctx, query)
+	if err != nil {
+		return &Row{err: err}
+	}
+	return stmt.QueryRowContext(ctx, args...)
+}
diff --git a/vendor/github.com/Masterminds/squirrel/stmtcacher_noctx.go b/vendor/github.com/Masterminds/squirrel/stmtcacher_noctx.go
new file mode 100644
index 0000000..deac967
--- /dev/null
+++ b/vendor/github.com/Masterminds/squirrel/stmtcacher_noctx.go
@@ -0,0 +1,21 @@
+// +build !go1.8
+
+package squirrel
+
+import (
+	"database/sql"
+)
+
+// NewStmtCacher returns a DBProxy wrapping prep that caches Prepared Stmts.
+//
+// Stmts are cached based on the string value of their queries.
+func NewStmtCache(prep Preparer) *StmtCache {
+	return &StmtCacher{prep: prep, cache: make(map[string]*sql.Stmt)}
+}
+
+// NewStmtCacher is deprecated
+//
+// Use NewStmtCache instead
+func NewStmtCacher(prep Preparer) DBProxy {
+	return NewStmtCache(prep)
+}
diff --git a/vendor/github.com/Masterminds/squirrel/update.go b/vendor/github.com/Masterminds/squirrel/update.go
new file mode 100644
index 0000000..eb2a9c4
--- /dev/null
+++ b/vendor/github.com/Masterminds/squirrel/update.go
@@ -0,0 +1,288 @@
+package squirrel
+
+import (
+	"bytes"
+	"database/sql"
+	"fmt"
+	"sort"
+	"strings"
+
+	"github.com/lann/builder"
+)
+
+type updateData struct {
+	PlaceholderFormat PlaceholderFormat
+	RunWith           BaseRunner
+	Prefixes          []Sqlizer
+	Table             string
+	SetClauses        []setClause
+	From              Sqlizer
+	WhereParts        []Sqlizer
+	OrderBys          []string
+	Limit             string
+	Offset            string
+	Suffixes          []Sqlizer
+}
+
+type setClause struct {
+	column string
+	value  interface{}
+}
+
+func (d *updateData) Exec() (sql.Result, error) {
+	if d.RunWith == nil {
+		return nil, RunnerNotSet
+	}
+	return ExecWith(d.RunWith, d)
+}
+
+func (d *updateData) Query() (*sql.Rows, error) {
+	if d.RunWith == nil {
+		return nil, RunnerNotSet
+	}
+	return QueryWith(d.RunWith, d)
+}
+
+func (d *updateData) QueryRow() RowScanner {
+	if d.RunWith == nil {
+		return &Row{err: RunnerNotSet}
+	}
+	queryRower, ok := d.RunWith.(QueryRower)
+	if !ok {
+		return &Row{err: RunnerNotQueryRunner}
+	}
+	return QueryRowWith(queryRower, d)
+}
+
+func (d *updateData) ToSql() (sqlStr string, args []interface{}, err error) {
+	if len(d.Table) == 0 {
+		err = fmt.Errorf("update statements must specify a table")
+		return
+	}
+	if len(d.SetClauses) == 0 {
+		err = fmt.Errorf("update statements must have at least one Set clause")
+		return
+	}
+
+	sql := &bytes.Buffer{}
+
+	if len(d.Prefixes) > 0 {
+		args, err = appendToSql(d.Prefixes, sql, " ", args)
+		if err != nil {
+			return
+		}
+
+		sql.WriteString(" ")
+	}
+
+	sql.WriteString("UPDATE ")
+	sql.WriteString(d.Table)
+
+	sql.WriteString(" SET ")
+	setSqls := make([]string, len(d.SetClauses))
+	for i, setClause := range d.SetClauses {
+		var valSql string
+		if vs, ok := setClause.value.(Sqlizer); ok {
+			vsql, vargs, err := vs.ToSql()
+			if err != nil {
+				return "", nil, err
+			}
+			if _, ok := vs.(SelectBuilder); ok {
+				valSql = fmt.Sprintf("(%s)", vsql)
+			} else {
+				valSql = vsql
+			}
+			args = append(args, vargs...)
+		} else {
+			valSql = "?"
+			args = append(args, setClause.value)
+		}
+		setSqls[i] = fmt.Sprintf("%s = %s", setClause.column, valSql)
+	}
+	sql.WriteString(strings.Join(setSqls, ", "))
+
+	if d.From != nil {
+		sql.WriteString(" FROM ")
+		args, err = appendToSql([]Sqlizer{d.From}, sql, "", args)
+		if err != nil {
+			return
+		}
+	}
+
+	if len(d.WhereParts) > 0 {
+		sql.WriteString(" WHERE ")
+		args, err = appendToSql(d.WhereParts, sql, " AND ", args)
+		if err != nil {
+			return
+		}
+	}
+
+	if len(d.OrderBys) > 0 {
+		sql.WriteString(" ORDER BY ")
+		sql.WriteString(strings.Join(d.OrderBys, ", "))
+	}
+
+	if len(d.Limit) > 0 {
+		sql.WriteString(" LIMIT ")
+		sql.WriteString(d.Limit)
+	}
+
+	if len(d.Offset) > 0 {
+		sql.WriteString(" OFFSET ")
+		sql.WriteString(d.Offset)
+	}
+
+	if len(d.Suffixes) > 0 {
+		sql.WriteString(" ")
+		args, err = appendToSql(d.Suffixes, sql, " ", args)
+		if err != nil {
+			return
+		}
+	}
+
+	sqlStr, err = d.PlaceholderFormat.ReplacePlaceholders(sql.String())
+	return
+}
+
+// Builder
+
+// UpdateBuilder builds SQL UPDATE statements.
+type UpdateBuilder builder.Builder
+
+func init() {
+	builder.Register(UpdateBuilder{}, updateData{})
+}
+
+// Format methods
+
+// PlaceholderFormat sets PlaceholderFormat (e.g. Question or Dollar) for the
+// query.
+func (b UpdateBuilder) PlaceholderFormat(f PlaceholderFormat) UpdateBuilder {
+	return builder.Set(b, "PlaceholderFormat", f).(UpdateBuilder)
+}
+
+// Runner methods
+
+// RunWith sets a Runner (like database/sql.DB) to be used with e.g. Exec.
+func (b UpdateBuilder) RunWith(runner BaseRunner) UpdateBuilder {
+	return setRunWith(b, runner).(UpdateBuilder)
+}
+
+// Exec builds and Execs the query with the Runner set by RunWith.
+func (b UpdateBuilder) Exec() (sql.Result, error) {
+	data := builder.GetStruct(b).(updateData)
+	return data.Exec()
+}
+
+func (b UpdateBuilder) Query() (*sql.Rows, error) {
+	data := builder.GetStruct(b).(updateData)
+	return data.Query()
+}
+
+func (b UpdateBuilder) QueryRow() RowScanner {
+	data := builder.GetStruct(b).(updateData)
+	return data.QueryRow()
+}
+
+func (b UpdateBuilder) Scan(dest ...interface{}) error {
+	return b.QueryRow().Scan(dest...)
+}
+
+// SQL methods
+
+// ToSql builds the query into a SQL string and bound args.
+func (b UpdateBuilder) ToSql() (string, []interface{}, error) {
+	data := builder.GetStruct(b).(updateData)
+	return data.ToSql()
+}
+
+// MustSql builds the query into a SQL string and bound args.
+// It panics if there are any errors.
+func (b UpdateBuilder) MustSql() (string, []interface{}) {
+	sql, args, err := b.ToSql()
+	if err != nil {
+		panic(err)
+	}
+	return sql, args
+}
+
+// Prefix adds an expression to the beginning of the query
+func (b UpdateBuilder) Prefix(sql string, args ...interface{}) UpdateBuilder {
+	return b.PrefixExpr(Expr(sql, args...))
+}
+
+// PrefixExpr adds an expression to the very beginning of the query
+func (b UpdateBuilder) PrefixExpr(expr Sqlizer) UpdateBuilder {
+	return builder.Append(b, "Prefixes", expr).(UpdateBuilder)
+}
+
+// Table sets the table to be updated.
+func (b UpdateBuilder) Table(table string) UpdateBuilder {
+	return builder.Set(b, "Table", table).(UpdateBuilder)
+}
+
+// Set adds SET clauses to the query.
+func (b UpdateBuilder) Set(column string, value interface{}) UpdateBuilder {
+	return builder.Append(b, "SetClauses", setClause{column: column, value: value}).(UpdateBuilder)
+}
+
+// SetMap is a convenience method which calls .Set for each key/value pair in clauses.
+func (b UpdateBuilder) SetMap(clauses map[string]interface{}) UpdateBuilder {
+	keys := make([]string, len(clauses))
+	i := 0
+	for key := range clauses {
+		keys[i] = key
+		i++
+	}
+	sort.Strings(keys)
+	for _, key := range keys {
+		val, _ := clauses[key]
+		b = b.Set(key, val)
+	}
+	return b
+}
+
+// From adds FROM clause to the query
+// FROM is valid construct in postgresql only.
+func (b UpdateBuilder) From(from string) UpdateBuilder {
+	return builder.Set(b, "From", newPart(from)).(UpdateBuilder)
+}
+
+// FromSelect sets a subquery into the FROM clause of the query.
+func (b UpdateBuilder) FromSelect(from SelectBuilder, alias string) UpdateBuilder {
+	// Prevent misnumbered parameters in nested selects (#183).
+	from = from.PlaceholderFormat(Question)
+	return builder.Set(b, "From", Alias(from, alias)).(UpdateBuilder)
+}
+
+// Where adds WHERE expressions to the query.
+//
+// See SelectBuilder.Where for more information.
+func (b UpdateBuilder) Where(pred interface{}, args ...interface{}) UpdateBuilder {
+	return builder.Append(b, "WhereParts", newWherePart(pred, args...)).(UpdateBuilder)
+}
+
+// OrderBy adds ORDER BY expressions to the query.
+func (b UpdateBuilder) OrderBy(orderBys ...string) UpdateBuilder {
+	return builder.Extend(b, "OrderBys", orderBys).(UpdateBuilder)
+}
+
+// Limit sets a LIMIT clause on the query.
+func (b UpdateBuilder) Limit(limit uint64) UpdateBuilder {
+	return builder.Set(b, "Limit", fmt.Sprintf("%d", limit)).(UpdateBuilder)
+}
+
+// Offset sets a OFFSET clause on the query.
+func (b UpdateBuilder) Offset(offset uint64) UpdateBuilder {
+	return builder.Set(b, "Offset", fmt.Sprintf("%d", offset)).(UpdateBuilder)
+}
+
+// Suffix adds an expression to the end of the query
+func (b UpdateBuilder) Suffix(sql string, args ...interface{}) UpdateBuilder {
+	return b.SuffixExpr(Expr(sql, args...))
+}
+
+// SuffixExpr adds an expression to the end of the query
+func (b UpdateBuilder) SuffixExpr(expr Sqlizer) UpdateBuilder {
+	return builder.Append(b, "Suffixes", expr).(UpdateBuilder)
+}
diff --git a/vendor/github.com/Masterminds/squirrel/update_ctx.go b/vendor/github.com/Masterminds/squirrel/update_ctx.go
new file mode 100644
index 0000000..ad479f9
--- /dev/null
+++ b/vendor/github.com/Masterminds/squirrel/update_ctx.go
@@ -0,0 +1,69 @@
+// +build go1.8
+
+package squirrel
+
+import (
+	"context"
+	"database/sql"
+
+	"github.com/lann/builder"
+)
+
+func (d *updateData) ExecContext(ctx context.Context) (sql.Result, error) {
+	if d.RunWith == nil {
+		return nil, RunnerNotSet
+	}
+	ctxRunner, ok := d.RunWith.(ExecerContext)
+	if !ok {
+		return nil, NoContextSupport
+	}
+	return ExecContextWith(ctx, ctxRunner, d)
+}
+
+func (d *updateData) QueryContext(ctx context.Context) (*sql.Rows, error) {
+	if d.RunWith == nil {
+		return nil, RunnerNotSet
+	}
+	ctxRunner, ok := d.RunWith.(QueryerContext)
+	if !ok {
+		return nil, NoContextSupport
+	}
+	return QueryContextWith(ctx, ctxRunner, d)
+}
+
+func (d *updateData) QueryRowContext(ctx context.Context) RowScanner {
+	if d.RunWith == nil {
+		return &Row{err: RunnerNotSet}
+	}
+	queryRower, ok := d.RunWith.(QueryRowerContext)
+	if !ok {
+		if _, ok := d.RunWith.(QueryerContext); !ok {
+			return &Row{err: RunnerNotQueryRunner}
+		}
+		return &Row{err: NoContextSupport}
+	}
+	return QueryRowContextWith(ctx, queryRower, d)
+}
+
+// ExecContext builds and ExecContexts the query with the Runner set by RunWith.
+func (b UpdateBuilder) ExecContext(ctx context.Context) (sql.Result, error) {
+	data := builder.GetStruct(b).(updateData)
+	return data.ExecContext(ctx)
+}
+
+// QueryContext builds and QueryContexts the query with the Runner set by RunWith.
+func (b UpdateBuilder) QueryContext(ctx context.Context) (*sql.Rows, error) {
+	data := builder.GetStruct(b).(updateData)
+	return data.QueryContext(ctx)
+}
+
+// QueryRowContext builds and QueryRowContexts the query with the Runner set by RunWith.
+func (b UpdateBuilder) QueryRowContext(ctx context.Context) RowScanner {
+	data := builder.GetStruct(b).(updateData)
+	return data.QueryRowContext(ctx)
+}
+
+// ScanContext is a shortcut for QueryRowContext().Scan.
+func (b UpdateBuilder) ScanContext(ctx context.Context, dest ...interface{}) error {
+	return b.QueryRowContext(ctx).Scan(dest...)
+}
diff --git a/vendor/github.com/Masterminds/squirrel/where.go b/vendor/github.com/Masterminds/squirrel/where.go
new file mode 100644
index 0000000..976b63a
--- /dev/null
+++ b/vendor/github.com/Masterminds/squirrel/where.go
@@ -0,0 +1,30 @@
+package squirrel
+
+import (
+	"fmt"
+)
+
+type wherePart part
+
+func newWherePart(pred interface{}, args ...interface{}) Sqlizer {
+	return &wherePart{pred: pred, args: args}
+}
+
+func (p wherePart) ToSql() (sql string, args []interface{}, err error) {
+	switch pred := p.pred.(type) {
+	case nil:
+		// no-op
+	case rawSqlizer:
+		return pred.toSqlRaw()
+	case Sqlizer:
+		return pred.ToSql()
+	case map[string]interface{}:
+		return Eq(pred).ToSql()
+	case string:
+		sql = pred
+		args = p.args
+	default:
+		err = fmt.Errorf("expected string-keyed map or string, not %T", pred)
+	}
+	return
+}