Creating a Check Constraint

Creating a check constraint specifies a condition that any value must pass before it is inserted into the table.

A check constraint specifies a condition that any value must pass before it is inserted into the table. You can create a check constraint at the table or column level. Column-level check constraints reference a single column. Table-level check constraints apply to the entire table.

In the left pane of the Administration Console, expand ASE Servers > Schema Objects > Tables, then choose one of the following:
- User Tables
- Proxy Tables
Click the Name field of the table, then click the drop-down arrow and select Properties.
In the left pane, click Check Constraint.
Select New.
On the Name screen, enter a name for the check constraint.
On the Expression screen, enter an expression that defines the constraint.
For example, salary > 0. The comparable command line syntax using alter table is:
```
alter table sample.dbo.employee
add constraint test_const
CHECK  (salary > 0)
```
(Optional) Click Summary to review the check constraint expression.
Click Finish .