如何在不使用“IN”的情况下在 MySQL 连接中使用字符串

Question

I have an variable of order ids like:

$OrderIds = "1,2,3,4,5,6"; //thousands of ids

I want to use this string with MySQL join, without using "IN" statement because "IN" statement take much time to execute and I think "IN" statement is not good for that kind of things.

Thanks in advance.

Answer 1

If you don't want to use IN you can use UNION:

$sql=""
$OrderIds=explode(',',$OrderIds);
for($i=0;$i++;$i<count($OrderIds)){
   $where.=" SELECT * FROM mytable WHERE orderId=".$OrderIds[$i]; //quote the id
   if($i<count($OrderIds)-1) $where.=" UNION ";
}
$db->query($sql);

But I would use IN!