Question

how can i insert into a row if the pair does not exist?
* NOTE these are not primary keys, my primary KEY is set to auto increment

tried insert ignore but did not work

INSERT IGNORE INTO mytable (`myid`, `theirid`) VALUES ('5', '1')
ON DUPLICATE KEY <DO NOTHING>

table looks like:

CREATE TABLE `mytable` (
    `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
    `myid` bigint(20) NOT NULL,
    `theirid` bigint(20) NOT NULL,
    `activated` tinyint(1) NOT NULL DEFAULT '0',
    `dateStamp` timestamp NULL DEFAULT CURRENT_TIMESTAMP,
    PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=10 DEFAULT CHARSET=latin1$$

Answer 1

1) Can you add a UNIQUE constraint on (myid, theirid)? If yes, add this constraint and use:

INSERT INTO mytable (myid, theirid) 
  VALUES (5, 1) ;

and ignore the produce warnings (or replace the above with INSERT IGNORE)

2) If you can’t add such a constraint (e.g. you sometimes want to allow such duplicates and other times you don’t), you can use this:

INSERT INTO mytable (myid, theirid) 
  SELECT 5, 1 
  FROM dual 
  WHERE NOT EXISTS
        ( SELECT *
          FROM mytable
          WHERE myid = 5
            AND theirid = 1
        ) ;