Online Documentation for SQL Manager for SQL server

Checks


A Check specifies an expression producing a Boolean result which new or updated rows must satisfy for an insert or update operation to succeed. Expressions evaluating to TRUE or UNKNOWN succeed. Should any row of an insert or update operation produce a FALSE result an error exception is raised and the insert or update does not alter the database. A check constraint specified as a column constraint should reference that column's value only, while an expression appearing in a table constraint may reference multiple columns.

 

Table checks are managed within the Checks tab of Table Editor.

 

 

Creating Checks

 

To create a new check:

  • open the table in Table Editor;
  • proceed to the Checks tab there;
  • right-click the tab area and select the New Check Constraint context menu item, or press the Ins key;
  • define the check properties using the Check Editor dialog.

 

Editing Checks

 

To view an existing check:

  • open the table in Table Editor;
  • proceed to the Checks tab there;
  • right-click the check and select the Edit Check <check_name> context menu item, or simply double-click the check;
  • edit the check properties using the Check Editor dialog.

 

Dropping Checks

 

To drop a check:

  • open the table in Table Editor;
  • proceed to the Checks tab there;
  • right-click the check and select the Drop Check <check_name> context menu item;
  • confirm dropping in the dialog window.