Question: I have the code below to query a table which retrieves arrays. The parameter $idList could have several values and may therefore produce duplicates. I am only interested in inserting one unique memalertid.

Any advice on how to remove the duplicates would be much appreciated.

```
$sql = mysql_query("SELECT  memalertid from memlist where listID IN ($idList) AND (emailyes = '1') ");
while ($info = mysql_fetch_array($sql)){
$insert_query = "insert into subsalerts (memalertid, idMembers, emailid) VALUES('".$info['memalertid']."','$idMembers','$emailid')";
$insert_buffer = mysql_query($insert_query);    

```

Thanks very much

Answer: 
```
$newArray = array_unique($yourArray);

```

This will create a new array only with unique values; excluding any duplicates.
No need to get PHP involved. Just `SELECT` using `GROUP BY`.

```
INSERT INTO subsalerts (memalertid, idMembers, emailid)
    SELECT memalertid, $idMembers, $emailid FROM memlist WHERE listID IN ($idList) AND emailyes = 1 GROUP BY memalertid;

```