How to delete duplicate rows from a MySQL table

Question

I have a MySQL table like:

ID, Col1, Col2, Col3, Col4, etc...

ID is a primary key and has been w

Answer 1

You can run an alter query and achieve this:

ALTER IGNORE TABLE tbl_1
ADD UNIQUE INDEX unq_idx(col1, col2, col3);

I cant guarantee it will retain the first record among the duplicates, but MySQL usually does that.