You have a table that you would like to have a primary key. You would like to add a new column to be the primary key. How do you do this?
Here is a SQL command that is an illustration. Assuming the table's name is "contint" and the new column you want to add is "continual_col" with a value type of integer, issue this command:
ALTER TABLE ADD COLUMN continual_col int PRIMARY KEY;
This is just an example. Your primary key may have a different data type and a different name for the column. Substitute "contint" and "continual_col" accordingly. Then run the command.