I like using this syntax in MySql coz it have a simple syntax and so efficient when I want to insert a record but if it already exist, it'll update the data... but it not too recommended, coz from the statement below.. REPLACE INTO will slower the performer...
1. Try to insert the new row into the table 2. While the insertion fails because a duplicate-key error occurs for a primary key or unique index: 1. Delete from the table the conflicting row that has the duplicate key value 2. Try again to insert the new row into the table
Syntac :: REPLACE INTO F SELECT * FROM T; REPLACE INTO F(a, b, c) SELECT a, b, c FROM T; Summary: REPLACE INTO becomes more efficient from DELETE FROM… INSERT INTO… but much slower performer than an UPDATE statement. Better use “INSERT … ON DUPLICATE KEY UPDATE…” as an alternative if you’re looking at a single unique column table (Primary Key).