Reference Editor is intended for editing the properties of a foreign key constraint, integrity rules, and choosing referenced columns.
To open the Reference Editor, simply double-click a reference on the diagram or select the Properties item from the reference context menu.
The dialog consists of several tabs, each of which is described in details below.
This tab allows you to set up the basic reference properties.
This tab allows to choose an active constraint of the referenced table and columns participated in the reference.
In the left side of the grid there is list of columns of referenced table. In the right side there is a list of corresponding foreign key columns of the referencing table.
To change assignment of foreign key column of the referencing table:
In this tab you can change integrity rules for foreign key constraint.
When record in referenced table is changed (updated or deleted), it is possible to automatically modify associated records in the referencing table. This is the function of delete/update rules of the constraint.
For example, there are two tables: Orders and Customers. The Orders table has the foreign key column CustID which refer to the Cusomers table. You can delete a record from the Customers table and corresponding records from the Orders table, using one DELETE statement. It is possible because of cascade delete rule.
You can assign a rule both to update and delete event. In the left side there is list of update rules. In the right side there is list of delete rules. Click on the appropriate list item to change a rule.
Update constraint. Sets a rule that will be executed on update of a referenced table's record:
Delete constraint. Sets a rule that will be executed on delete of a referenced table's record:
The Note tab allows you to define a description and an annotation for the edited reference. This properties will not affect the physical database, but they can be useful for your diagram development.
In this tab you can choose the colors which will be used for displaying edited reference on the diagram.