Building an array, kind of?

TGIF? Apparently my brain isn't working this Friday. I'm trying to query my table to get the first 16 ID's. I then want to assign the ID's to a variable and have them comma seperated. // My query to select the first 16 rows $get_charges2 = "SELECT FIRST 16 * FROM history WHERE id = '$id"; // Executing the query $charge_result2 = ifx_query ($get_charges2, $connect_id); How would I assign the result to a variable? For instance, say my query returns rows like: 1234 1235 1236 1237 1238 1239 How would I go about putting that in a variable to equal "1234,1235,1236,1237,1238,1239" ?