How to create a new identifier column on an existing table (Enterprise Manager)

To create a new identifier column on an existing table

1. Expand a server group; then expand a server.
2. Expand Databases, expand the database in which the table belongs, and then click Tables.
3. In the details pane, right-click the table, and then click Design Table.
4. In a blank row, specify the column name and data type for the identifier column. Each row represents one column in the table.
5. Clear the Allow Nulls check box.
6. Check the box inside the:
   • Is RowGuid cell to create a globally unique identifier column. Globally unique identifier columns must have a data type of uniqueidentifier. A Default Value of newid() is created automatically.
   • Identity cell to create a unique identifier column. Identifier columns must have data types of int, smallint, tinyint, decimal, or numeric.
7. Optionally, for the Identity column, type a value in the Identity Seed cell.

   This value will be assigned to the first row in the table. If you leave this cell blank, the value 1 will be assigned by default.

8. Optionally, for the Identity column, type a value in the Identity Increment cell.

   This value is the increment that will be added to the Identity Seed for each subsequent row. If you leave this cell blank, the value 1 will be assigned by default.

   For example, suppose you want to automatically generate a 5-digit Order ID for each row added to the orders table, beginning with 1000 and incremented by a value of 10. To do this, you would check the Identity property box, type an Identity Seed of 1000, and type an Identity Increment of 10.

See Also

Creating and Modifying Identifier Columns