<< Click to Display Table of Contents >>

Representation of Relations

Top Previous Next

Each relationship between two tables is represented by a line connecting the parent table shape with the child table shape. Depending on the auto-layout options, the foreign key's name is optionally displayed next to the line.

The child side of the connection is pictured by a solid dot.

ErDgr3

The parent side of the connection line leads directly into the parent shape when the relation is mandatory. That happens only if all foreign-key columns in the child table have the not null attribute.

A box shape is used to indicate the parent side of an optional connection.

ErDgr2

 

Relationships based on a foreign key with the cascading delete option use a red line (as in the first illustration above).