[mysql] MySQL: Insert record if not exists in table

I had a problem, and the method Mike advised worked partly, I had an error Dublicate Column name = '0', and changed the syntax of your query as this`

     $tQ = "INSERT  INTO names (name_id, surname_id, sum, sum2, sum3,sum4,sum5) 
                SELECT '$name', '$surname', '$sum', '$sum2', '$sum3','$sum4','$sum5' 
FROM DUAL
                WHERE NOT EXISTS (
                SELECT sum FROM names WHERE name_id = '$name' 
AND surname_id = '$surname') LIMIT 1;";

The problem was with column names. sum3 was equal to sum4 and mysql throwed dublicate column names, and I wrote the code in this syntax and it worked perfectly,