Check Constraints, Designer

List of Check Constraints

In this section, you manage the check constraints for the table and set their properties.

Check Constraints

Lists the constraints in the order that they will appear in the generated code. Type a name for the check constraint. This name can contain up to 18 characters and can be an ordinary identifier or a delimited identifier.

Check Constraint Properties

Set the property values for the check constraint that is selected in the Check Constraints list. An unavailable property is a limitation of the database that you are using.

Select a property to see its description in the box under the properties list. If the description exceeds the size of the box, hover the mouse pointer over the last line of text in the box. After a brief pause, the full description is shown in a ScreenTip.

Constraint Expression

In this section, you specify the expression for the check constraint that is selected in the Selected Check Constraint list. Check constraints are not checked for inconsistencies, duplicate conditions, or equivalent conditions. Therefore, contradictory or redundant check constraints can result in errors at run time.

The DB2 syntax for a check constraint is:  CHECK (check-condition)

Additional information is available in your DB2 documentation. You can also find information in DB2 SQL documentation that is available through The SQL Reference for Cross-Platform Development Web page on developerWorks.

To use the Visual Studio Query Builder to create a constraint that is an SQL expression, right-click in this editor, and then select Query Builder on the shortcut menu. When you close the Query Builder, the SQL code in the Query Builder is automatically pasted in this editor at the insertion point.