Question

I have a table with a unique key for two columns:

CREATE  TABLE `xpo`.`user_permanent_gift` (
`id` INT UNSIGNED NOT NULL AUTO_INCREMENT ,
`fb_user_id` INT UNSIGNED NOT NULL ,
`gift_id` INT UNSIGNED NOT NULL ,
`purchase_timestamp` TIMESTAMP NULL DEFAULT now() ,
PRIMARY KEY (`id`) ,
UNIQUE INDEX `user_gift_UNIQUE` (`fb_user_id` ASC, `gift_id` ASC) );

I want to insert a row into that table, but if the key exists, to do nothing! I don’t want an error to be generated because the keys exist.

I know that there is the following syntax:

INSERT ... ON DUPLICATE KEY UPDATE ...

but is there something like:

INSERT ... ON DUPLICATE KEY DO NOTHING 

?

Answer 1

Yes, use INSERT ... ON DUPLICATE KEY UPDATE id=id (it won’t trigger row update even though id is assigned to itself).

If you don’t care about errors (conversion errors, foreign key errors) and autoincrement field exhaustion (it’s incremented even if the row is not inserted due to duplicate key), then use INSERT IGNORE like this:

INSERT IGNORE INTO <table_name> (...) VALUES (...)