Creating Alternate Keys

An alternate key is a key associated with one or more columns whose values uniquely identify every row in the table, but which is not the primary key. For example, where the primary key for a table may be the employee id, the alternate key might combine the first, middle, and last names of the employee. Each alternate key can generate a unique index or a unique constraint in a target database.

1. Open the property sheet of a table and select the Columns tab.
2. Select the column or columns to associate with the alternate key and click the Create Key tool.
   The new key property sheet opens.
3. Enter a name for the key. Alternate keys are conventionally named AKx_ColumnCodes (for example AK1_CUSNAME).
4. [optional] Modify the default Constraint Name.
5. Click OK to complete the creation of your alternate key and return to the table property sheet.
   Note: You can also create an alternative key using the Add a Row tool on the table property sheet Keys tab, click the Properties tool to open its property sheet, and select the Columns tab to manually associate columns with the key.