Creating a Table Check Constraint

A table check constraint ensures that no row in a table violates the constraint, which may include more than one column in its specification.

Prerequisites

Database Version	Table Constraint Privileges
SAP Sybase IQ 15.3 and 15.4	Requires one of: DBA authority. ALTER permission on the underlying table. You own the underlying table.
SAP Sybase IQ 16.0	Requires one of: ALTER ANY OBJECT system privilege. ALTER ANY TABLE system privilege. You have ALTER permission on the underlying table. You own the underlying table.

The SAP Sybase IQ resource is authenticated and running.
In a multiplex configuration, the coordinator node is running.

Task

In the Perspective Resources view, select the resource and select Resource > Administration Console.
In the Administration Console, expand IQ Servers > Schema Objects > Tables.
Select Tables or Global Temporary Tables, select the table in the right pane, click the drop-down arrow that appears to the right, and select Properties.
Select Constraints.
Click New.
The Create Constraint Wizard appears.
On the Welcome page, specify a table check key constraint:

Option Description

Select the type of constraint From the Select an item pull-down, select Table check constraint.
Click Next.
On the Constraint Name page, specify:

Option Description

What do you want to name the new check constraint? Specify a descriptive name for the check constraint.
Click Next.
On the Definition page, specify:

Option Description

Specify a condition to restrict the values. SQL definition of the check constraint.
Use this example as a model when specifying a definition:
```
CHECK(TerminationDate >= StartDate);
```
This example adds a constraint on the Employees table to ensure that the TerminationDate is always later than, or equal to, the StartDate.

Tip: The table check constraint definition can include multiple columns.
Click Next.
On the Comment page, add an optional, descriptive comment. Comments help you organize your database.
Click Finish to close the Create Constraint Wizard.
The Properties view appears.
Tip: Although you closed the Create Constraint Wizard, the constraint is still in-progress until you click Apply and OK in step 14. If there is a problem with the constraint, modify the in-progress constraint by clicking Properties and then making the necessary changes.
Click Apply and OK.