Specifying a Table Column as a Primary Key

You can specify a table column as a primary key from the Columns page of the Table Editor tab.

To specify a table column as a primary key

1. From the Object Explorer, open the table that you want to edit.
   The table appears in the Table Editor tab.
2. In the Columns page, right-click the grid row of the table column that you want to specify as a primary key.
3. Select Primary Key from the popup menu. A primary key icon is displayed in the Headings Row column, indicating that the primary key contains the column.

Notes

• A primary key column cannot accept NULL values.
• The unique combination of values in a composite primary key forms an index.
  For best performance, place the columns in the order that you use them.
• Columns containing BYTE or TEXT data types cannot be selected as primary keys.