Difference Between Strong and Weak Entity

In this post, we will understand the difference between strong entity and weak entity −

Strong Entity

• It has primary key.

• It doesn’t depend on any other entity.

• It can be represented using a single rectangle.

• The relationship between two strong entities can be represented using a single diamond.

• It can either have total participation or no participation.

Weak Entity

• A weak entity has a partial discriminator key.

• It depends on the strong entity.

• It can be represented using a double rectangle.

• The relationship between a strong and a weak entity can be represented using a double diamond.

• They always have total participation.