@startuml
!define Table(name,desc) class name as "desc" << (T,#FFAAAA) >>
!define primary_key(x) <b>x</b>
!define foreign_key(x) <b>x</b>
!define unique(x) <color:green>x</color>
!define not_null(x) <u>x</u>
hide methods
hide stereotypes

' entities
Table(customer, "Customer") {
  primary_key(id) INTEGER
  not_null(name) VARCHAR[255]
}

Table(address, "Address") {
  primary_key(id) INTEGER
  foreign_key(customer_id) INTEGER
  not_null(street) VARCHAR[255]
  not_null(city) VARCHAR[255]
  not_null(country) VARCHAR[255]
}

' relationships
customer --|{ address
@enduml