Add Relations

The Add Relations dialog box in Server Explorer in Visual Studio enables you to create primary key and foreign key relations in SQL Server Compact. 

Options

Relation Name

Specify a name for the relation.

Update Rule

Enables you to update rules by using the following options:

NO ACTION, CASCADE, SET NULL, SET Default

If you specify NO ACTION, SQL Server Compact returns an error, and the update action on the referenced row in the parent table is rolled back. 

If you specify the CASCADE option and the corresponding referenced row is updated in the parent table, the row is updated in the referencing table.

For example, you might have two tables, A and B, in a database. Table A has a referential relationship with table B: The A.ItemID foreign key references the B.ItemID primary key.

If an UPDATE statement is executed on a row in table B and an ON UPDATE CASCADE action is specified for A.ItemID, SQL Server Compact checks for one or more dependent rows in table A. If any exist, the dependent rows in table A are updated and the row that is referenced in table B is updated.

Delete Rule

Enables you to delete rules by using the following options:

NO ACTION, CASCADE, SET NULL, SET Default

If you specify NO ACTION, SQL Server Compact returns an error, and the delete action on the referenced row in the parent table is rolled back. 

If you specify the CASCADE option and the corresponding referenced row is deleted in the parent table, the row is deleted in the referencing table.

For example, you might have two tables, A and B, in a database. Table A has a referential relationship with table B: The A.ItemID foreign key references the B.ItemID primary key.

If an UPDATE statement is executed on a row in table B and an ON UPDATE CASCADE action is specified for A.ItemID, SQL Server Compact checks for one or more dependent rows in table A. If any exist, the dependent rows in table A are deleted and the row referenced in table B is deleted.

Primary Key Table

Select the primary key table.

Foreign key table

Select the foreign key table.

Primary Key Table Column

Select the columns under the Primary key table list.

Foreign Key Table Column

Select the columns under the Foreign key table list.

Add Columns

Click Add Column to add the list of Primary key table columns and Foreign key table columns to the Manage Rules in Relation group box.

Delete Column

Click Delete to remove the selected Primary key table columns and Foreign key table columns that were added to the Manage Rules in Relation group box.

Add Relation

Click the Add Relation button to create the relation between the primary key table columns and the foreign key table columns that appear in the Manage Rules in Relation group box.