Add an example of a weak entity

2 files changed, 25 insertions, 0 deletions

diff --git a/assignments/1/README.md b/assignments/1/README.md
index 1929ff0..a91c1e5 100644
--- a/assignments/1/README.md
+++ b/assignments/1/README.md
@@ -50,6 +50,17 @@ a. Associative entity
   ![associative entity example](./associative-entity.png)
 
 b. Weak entity
+
+  A strong entity is a type of entity that exists independent of any other entity types.
+  A weak entity is a type of entity that exists when some other type exists so it is dependent on an identifying owner.
+
+  Customer (id, name)
+  Address(id, customer_id, street, city, country)
+
+  Customer --<- Dependent
+
+  ![weak entity example](./weak-entity.png)
+
 c. Unary relationship
 
 ### Question 3 (20 marks)
diff --git a/assignments/1/weak-entity.yml b/assignments/1/weak-entity.yml
new file mode 100644
index 0000000..ff5b968
--- /dev/null
+++ b/assignments/1/weak-entity.yml
@@ -0,0 +1,14 @@
+@startuml
+entity "Customer" as customer {
+  *id: number
+  *name: varchar(255)
+}
+entity "Address" as address {
+  *id: number
+  *customer_id: number
+  *street: varchar(255)
+  *city: varchar(255)
+  *country: varchar(255)
+}
+customer ||..|{ address
+@enduml