Check Constraint

The check Constraint allows you to specify allowable values for a particular Column.

For example, you can require that a particular Column contain either a Yes or No value in every row.

If any row contains a different value for the Column, the system generates an error to the Program writing to the Table instance. If the Program does not handle the error, the job fails.

Note:

Oracle does not verify that check Constraints are not mutually exclusive. Therefore, if you create multiple check Constraints, design them carefully so their purposes do not conflict. Do not assume any particular order of evaluation of the conditions.

To define a Check Constraint:

1. Select Check Constraints from the Type drop-down list. The system refreshes the lower portion of the screen.
2. From the Column Name drop-down list, select the Column for which you want to define a list of allowable values.
3. In the Column Values section, enter one allowable Check Value value in the first row.
4. To add an additional row, click Add Another Row.
5. Click Apply.