Only insert if the value doesn't exist

Question

+----+----------+-----------+
| id | gamertag | timestamp |
+----+----------+-----------+

So I have the table above I want to only insert a gamertag if it doesn't already exist. How could I do that?

$gamertag = "l RaH l";
mysql_query("INSERT INTO `gamertags`(`gamertag`)VALUES ('".$gamertag."')");

Answer 1

You should do both things: Create a unique index on column gamertag and use insert ignore.

The unique index prevents a duplicate row from being added.

The insert ignore prevents mysql from issuing a warning when the duplicate row is not added.