
+---------------------+---------------------------------+--------------------+

Ignored errors normally generate a warning.

A property of the IGNORE clause consists in causing transactional engines and
non-transactional engines (like XtraDB and Aria) to behave the same way. For
example, normally a multi-row insert which tries to violate a UNIQUE contraint
is completely rolled back on XtraDB/InnoDB, but might be partially executed on
Aria. With the IGNORE clause, the statement will be partially executed in both
engines.

Duplicate key errors also generate warnings. The OLD_MODE server variable can
be used to prevent this.

URL: https://mariadb.com/kb/en/ignore/