Question

how to set primary key manually​

Answer 1

Answer:

To set the primary key: Open the database that you want to modify. In the Navigation Pane, right click the table in which you want to set the primary key and, on the shortcut menu, click Design View. Tip: If you don't see the Navigation Pane, press F11 to display it.

Answer 2

SQL PRIMARY KEY on ALTER TABLE. ADD CONSTRAINT PK_Person PRIMARY KEY (ID,LastName); Note: If you use the ALTER TABLE statement to add a primary key, the primary key column(s) must already have been declared to not contain NULL values (when the table was first created).