Turning off allowing multiple non-unique rows

[jackz15]

I feel lazy and I am busy so i don't want to fix my perl code to only alllow insertion of unique rows. I know mysql is set to allow multiple rows of the same thing but I would like to turn that feature off. Is that possible?

 

[Kozusnik]

ALTER TABLE `tablename` ADD UNIQUE (`fieldname`)

Now remember, this will fail if there is data in the table that is not unique. You may have to copy to a new table, truncate the table, add the unique, and copy the data back.
Mark

 

[guelphdad]

You don't even need to do all that just run:

ALTER IGNORE TABLE tablename ADD UNIQUE INDEX (fieldname);