Relationship Types of CA #ERwin

#Architecture #Datamodeling

CA ERwin supports three types of logical relationships between entities:

  1. Identifying relationships
  2. Many-to-many relationships
  3. Non-identifying relationships

This article explains these three relationship types in more detail in the following sections.

Identifying Relationships

In ERwin, an identifying relationship is represented by a solid line and is the relationship between the primary key of the parent entity and the primary key of the child entity.

In an identifying relationship, the foreign key migrates above the line and becomes part of the primary key of the child entity.

Many-to-Many Relationships

Many-to-many relationships define a relationship between two entities where a parent row might have many children and vice-versa:

Non-Identifying Relationships

Non-identifying relationships are represented by a dashed line in ERwin. It is the relationship between the primary key of the parent entity and a non-key attribute of the child table.

In a non-identifying relationship, the foreign key migrates below the line and becomes a non-key attribute in the child entity.

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