Converting ER diagrams to relational schema in DBMS Theory - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the first step in converting an ER diagram to a relational schema?

Identify all the entities in the ER diagram and create a separate table for each entity.

beginner

How are attributes of an entity represented in the relational schema?

Attributes of an entity become columns (fields) in the corresponding table.

intermediate

How is a one-to-many (1:N) relationship represented in a relational schema?

Add the primary key of the 'one' side entity as a foreign key in the table of the 'many' side entity.

intermediate

How do you convert a many-to-many (M:N) relationship from an ER diagram to a relational schema?

Create a new table for the relationship with foreign keys referencing the primary keys of the related entities. This table may also include attributes of the relationship.

beginner

What is the role of primary keys in the relational schema derived from an ER diagram?

Primary keys uniquely identify each record in a table and are usually derived from the entity's key attributes in the ER diagram.

When converting an ER diagram, what does each entity become in the relational schema?

A A foreign key

B A column

C A table

D A relationship

Each entity in an ER diagram is converted into a table in the relational schema.

How are attributes of an entity represented in the relational schema?

A As rows in a table

B As columns in a table

C As separate tables

D As foreign keys

Attributes become columns (fields) in the table representing the entity.

In a one-to-many relationship, where is the foreign key placed?

A In the 'many' side table

B In a new table

C No foreign key is needed

D In the 'one' side table

The foreign key is placed in the table on the 'many' side to reference the 'one' side.

What do you create to represent a many-to-many relationship in a relational schema?

A A new table with foreign keys

B A foreign key in one table

C A column with multiple values

D No table is needed

A new table (junction table) is created with foreign keys referencing the related entities.

What uniquely identifies each record in a relational table?

A Foreign key

B Relationship

C Attribute

D Primary key

The primary key uniquely identifies each record in a table.

Explain the process of converting a one-to-many relationship from an ER diagram into a relational schema.

Think about where the foreign key should go to link the tables.

Describe how many-to-many relationships are handled when converting ER diagrams to relational schemas.

Consider how to represent connections that involve multiple records on both sides.