在pdo中多次分配相同的参数值 [英] Assigning the same parameter value multiple times in pdo execute
问题描述
我最初有一条SQL语句,
I originally had an SQL statement, this:
SELECT *, COUNT(friend_one) AS pending_count , COUNT(friend_two) AS requests_sent
FROM friends
WHERE friend_one OR friend_two = ?
AND status = ?
我在其中分配了像这样的参数:
In which I assigned my parameters like :
$pending_friend_count_stmt->execute(array($user_id, $status_one));
但是,查询没有得到我想要的结果.有人向我展示了另一种方法,但是它多次包含变量$user_id
,因此我不知道如何调整代码以使用参数.
However, the query was not getting the results I wanted. Someone showed me a different way of doing it, but it has the variable $user_id
in it multiple times, so I do not know how to adjust the code to be able to use a parameter.
您可以在此处查看新查询:
You can see the new query here:
我能做到吗
SELECT COUNT(CASE WHEN `friend_one` = ? THEN 1 END) as `requests_count`,
COUNT(CASE WHEN `friend_two` = ? THEN 1 END) as `pending_count`
FROM `friends`
WHERE ? IN ( `friend_one` , `friend_two` )
AND `status` = ?
$pending_friend_count_stmt->execute(array($user_id, $user_id, $user_id $status_one));
推荐答案
使用PDO,您可以使用命名参数,但是在您的问题中,您希望对多个值使用1个参数,这意味着必须启用仿真:
Using PDO you have the ability to use named parameters, however in your question you want to use 1 parameters for multiple values and that means emulation has to be on:
$db->setAttribute(PDO::ATTR_EMULATE_PREPARES, true);
现在您可以执行以下操作:
Now you can do the following:
$stmt = $db->prepare("SELECT * FROM table WHERE userid = :userid AND userid = :userid");
$stmt->excecute([
':userid' => 1
]);
结果:
"SELECT * FROM table WHERE userid = 1 AND userid = 1"
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