[Resolved] preventing duplicate rows

Davidc316

There's a command you can do in MySQL that prevents table rows from being duplicated.

The way it works is you declare certain rows in your table as being unique.

It's in the MySQL manual somewhere. I've used this function before, but I forget what the excact MySQL command is and I'm absolutely kicking myself!!!

I'm looking through the MySQL manual right now. I know it's there somewhere. But if you can help me to figure out what the command is, I'm be very grateful.

Thanks!

PS- what an idiot I am for not writing that one down!!!

bad76

Hi,
you can set a field as UNIQUE when you create the table, or with ALTER TABLE. But the easiest way is to use phpmyadmin or any other mysql frontend. Edit table properties and set the field you want as unique...

see you

LordShryku

Should be be able to do it when you create your table by setting a unique constraint or primary key

CREATE TABLE test (
    test1 VARCHAR(10) ,
    test2 VARCHAR( 12 ) NOT NULL,
  PRIMARY KEY(test1),
  UNIQUE (test2)
);

Davidc316

Thanks guys.

The trouble with that is...

In my case, I'm hoping to make 4 separate columns unique.

They would be "event", "location", "email" and "telnum".

So, I'm hoping to have it so that a person would be able to theoretically submit lots of entries with the same entry for "email" (for instance), BUT if they happened to submit the same entries for all of those four columns, then I'm hoping that the thing would not insert the record.

So, do any of you know a way to make a collective group of four columns unique? Thanks!

PS- this is for the page www.topgig.com/tickets.php incase anyone's interested

laserlight

hmm... in that case, maybe you should just attempt to select from a row with all the 4 given columns.

If a record is found that matches, then you deny the new record.

Davidc316

Lazer- that's exactly what I had to do. You were right!

It was just a case of finding the right MySQL command and fortunately I think finally found the command I've been looking for.

Thanks folks! I owe you one! 😃