我有一个查询,可以让我更改用户订单。
这是我的查询:
update test set orderID =
case orderID
when (select orderID from ( select * from test where orderID > ( select orderID from test where id = 'id I want to move up' ) limit 1) as nextOrderID ) then ( select orderID from ( select * from test where id = 'id I want to move up') as nextOrderID )
when ( select orderID from ( select * from test where id = 'id I want to move up' ) as nextOrderID ) then (select orderID from ( select * from test where orderID > ( select orderID from test where id = 'id I want to move up' ) limit 1) as nextOrderID )
else
orderID
end
我想知道执行该查询是否不会花费很多时间,如果会,如何使其加载更快,是否可以减少该查询?
更新:
我对代码进行了一些编辑,所以现在我认为它会更快地执行查询。这是代码的一部分:
$query = "
SELECT (
SELECT orderID
FROM test WHERE id = 'user id that i want to move up'
) AS user_order,
(
SELECT orderID
FROM test WHERE orderID > user_order
ORDER BY orderID
LIMIT 0,1
) AS nextUser_order
";
$result = mysql_query($query);
$data = mysql_fetch_assoc($result);
$query = "
UPDATE test SET orderID = IF(orderID='{$data[nextUser_order]}',
'{$data[user_order]}', '{$data[nextUser_order]}')
WHERE orderID IN ('{$data[nextUser_order]}', '{$data[user_order]}');
";
$result = mysql_query($query);