【MYSQL】判斷欄位是否存在

$result = db_query("DESCRIBE imw_meeting");
while($rs = db_fetch_object($result)){
 $row[] = $rs->Field;
}

// 是否有我要的欄位
if (!in_array('proxy_user_id',$row)){
 db_query("ALTER TABLE imw_meeting ADD proxy_user_id INT NOT NULL AFTER user_id;");
}
if (!in_array('proxy_user_type_id',$row)){
 db_query("ALTER TABLE imw_meeting ADD proxy_user_type_id INT NOT NULL AFTER proxy_user_id;");
}