How do MySQL’s LAST_INSERT_ID() and INSERT … ON DUPLICATE KEY Work Together

What happens when an INSERT ... ON DUPLICATE KEY statement is followed by LAST_INSERT_ID() when an update is made? Does LAST_INSERT_ID() return the ID of the row updated? MySQL's documentation on INSERT ... ON DUPLICATE KEY states that... If a table contains an AUTO_INCREMENT column and INSERT ... ON DUPLICATE KEY UPDATE inserts or updates… Continue reading How do MySQL’s LAST_INSERT_ID() and INSERT … ON DUPLICATE KEY Work Together