Mysql: On duplicate key ignore?

This question already has an answer here:

• “INSERT IGNORE” vs “INSERT … ON DUPLICATE KEY UPDATE” 

Guys I'm trying to finish this query -> my tag field is set to UNIQUE and I simply want 

the database to ignore any duplicate tag.

INSERT INTO table_tags (tag) VALUES ('tag_a'),('tab_b'),('tag_c')
ON DUPLICATE KEY IGNORE '*the offending tag and carry on*'

or even this would be acceptable

INSERT INTO table_tags (tag) VALUES ('tag_a'),('tab_b'),('tag_c')
ON DUPLICATE KEY UPDATE '*the offending tag and carry on*'

 Answers

Would suggest NOT using INSERT IGNORE as it ignores ALL errors (ie its a sloppy global 

ignore). Instead, since in your example tag is the unique key, use:

INSERT INTO table_tags (tag) VALUES ('tag_a'),('tab_b'),('tag_c') ON DUPLICATE 

KEY UPDATE tag=tag;

on duplicate key produces:

Query OK, 0 rows affected (0.07 sec)