"INSERT IGNORE" vs "INSERT ... ON DUPLICATE KEY UPDATE"

I would recommend using INSERT...ON DUPLICATE KEY UPDATE. If you use INSERT IGNORE, then the row won't actually be inserted if it results in a duplicate key. But the statement won't generate an error. It generates a warning instead. These cases include: Inserting a duplicate key in columns with PRIMARY KEY or UNIQUE constraints. Inserting a NULL into a column with a NOT NULL constraint. Inserting

[a_bicky]

REPLACEはDELETE + INSERTだから論外で、INSERT IGNORE使うぐらいだったらON DUPLICATE KEY UPDATEで同じ値を割り当てた方が良さそう