The idea to add a UNIQUE index is OK, but the way you propose it is not correct.

You are adding a UNIQUE KEY which consists of both the questions field and all the option_? fields, which means that for the same question but with a different set of options, you get a different entry in the index and hence the "NOT UNIQUE" error doesn't trigger.

The solution is therefore to add a UNIQUE KEY on the questions field only and then you can add only one record with this question and all later records with the same question (but with perhaps different options) will not get added to the database.

CountZero

"If you have four groups working on a compiler, you'll get a 4-pass compiler." - Conway's Law

In reply to Re: Re: OT: routine for finding duplicate entries from a MySQL Table by CountZero
in thread OT: routine for finding duplicate entries from a MySQL Table by soon_j

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