Remove duplicates in Arrays from MYSQL query and then insert into another table

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']."','$idMember开发者_开发技巧s','$emailid')";
$insert_buffer = mysql_query($insert_query);    

Thanks very much

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Simply use SELECT DISTINCT to select distinct rows.

SELECT DISTINCT memalertid FROM memlist WHERE listID IN ($idList) AND (emailyes = '1')

You could also GROUP BY memalertid instead.

SELECT memalertid FROM memlist WHERE listID IN ($idList) AND (emailyes = '1') GROUP BY memalertid

For more information: http://dev.mysql.com/doc/refman/5.5/en/select.html.

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$newArray = array_unique($yourArray);

This will create a new array only with unique values; excluding any duplicates.

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You can use group by clause to group the results with the same id, so that you'll get only unique ids

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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;