Page 1 of 1

field change into unique? MySQL

Posted: Fri May 04, 2012 7:38 am
by wvoyance
My database MySQL already had some data inside.
I would like to change one field into unique field.
May I? and, how? Thanks.

Re: field change into unique? MySQL

Posted: Fri May 04, 2012 9:44 am
by x_mutatis_mutandis_x
First make sure the data in your column is unique. Assuming it is unique, then you can use the ALTER TABLE syntax:

Code: Select all

ALTER TABLE table_name ADD CONSTRAINT constraint_name UNIQUE (column_name)