How do I create contextual AUTO_INCREMENT in MySql?

Question

I want to Create a Contextual increment, not sure of term I am using is correct. here is my table

CREATE TABLE IF NOT EXISTS `test` (
  `id` int(10) NOT NULL         


        

Answer 1

You've got to swap the order of your indexes:

CREATE TABLE IF NOT EXISTS `test` (
    `id` int(10) NOT NULL AUTO_INCREMENT,
    `abc` varchar(50) NOT NULL,
    `data` varchar(100) NOT NULL,
    PRIMARY KEY (`abc`, `id`)   -- id got to be second
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;

I cite from the manual:

For MyISAM tables, you can specify AUTO_INCREMENT on a secondary column in a multiple-column index.

Working example in this fiddle