Question

Consider the following set of requirement for a BANK database. Then draw an ER diagram based the requirement.

The database keeps track of each back’s name, routing number, address. Banks has bank branch (you could name the relationship as BRANCHES). The bank branch described as branch name, branch location and branch ID. The branch ID is unique for each bank, but not unique in general.

Users open account in bank branches. The accounts described by account number, account type, account password.

Users could own several account. One user should have at least one account.

Account could create transactions. The transaction described by transaction ID, amount and type of transactions.

You should draw entity types, attributes and relationships in the ER diagram [10 points].

Specify key attributes of each entity type [3 points].

Use double lined rectangular to represent weak entity types [2 points].

Specify (min, max) on relationships [10 points].

Answer 1

The ER diagram of the given scenario is given below. It consist of 5 entities connected via 4 relationship. Each entity has certain set of attribute and primary key is mention as underlined attribute.

In ERD entity branch is week entity as branch id does not uniquely identifies a branch, it should be combined with bank routing_num to identify a branch. Hence is shown in double lined rectangle.

Cardinality between the entities is shown using crow's foot notation.