Defining Unique Constraints

Constraints define the conditions that must be met before values are accepted in the columns of a table.

To define a unique constraint

1. In the Table Editor, open the table where you want to define a unique constraint. The table appears in the Table Editor document.
2. Click the Constraints tab.
3. Click the cell in the empty row of the Type column. A default constraint name appears.
4. Enter a new name if you want to change the default constraint name.
5. Select Unique from the list box. The Unique Columns dialog box is displayed.
6. Check the boxes of the table columns that define the unique constraint.
7. Click OK to display the settings on the Constraints page.
8. Choose Table -> Execute to save your settings to the database.

Tip

BYTE and TEXT data type columns cannot be a part of a unique constraint.