Php 使查询更高效（真正缓慢的查询永远耗时！）

我想做的是让所有的用户都具备合适的条件 因此，我正在构建一个

foreach statment

sub_查询，以使其工作

问题是我在数据库中得到了100000多条记录。 而这种查询需要永远运行

我知道我做的不是最好的方式，但我也尝试了左连接，这也是非常缓慢的

这是我正在使用的函数：

    public function get_affected_users_by_conditions($conditions, $mobile_type)
    {
        // Basic Query 
        // Selecting all of the users from `enswitch_mobile users` table
        // The total and the `users` with the conditions
        $sql = "SELECT COUNT(*) AS `users`,
                       (SELECT COUNT(*) FROM `enswitch_mobile_users`) AS `total`
                FROM 
                    `enswitch_mobile_users` AS `musers`
                WHERE 
                    `musers`.`phone_type` = :mobile_type";

        $value_counter = 0;
        $values = array();
        // This is the foreach loop I was talking about
        // I am looping all the conditons.
        // and when theres a value i'm adding it as a subquery.
        foreach($conditions as $cnd) {
            switch ($cnd['condition']) {

                // REALLY SLOW SUB-QUERY:
                case 'talked_atleast':
                    $value_counter++;
                    // Here I'm trying to CUT the query by users who talked atleast $value seconds
                    $sql .= " AND (SELECT SUM(TIME_TO_SEC(TIMEDIFF(`finished_call`,`start_call`))) FROM `enswitch_calls` WHERE `user_id` = `musers`.`id`) >= :value".$value_counter;
                    $values[$value_counter] = $cnd['value'];
                    break;

// REALLY SLOW SUB-QUERY:
                case 'purchase_atleast':
                    // Here I am trying to CUT the users by subquery who check if the users has bought at least $value times
                    $value_counter++;
                    $sql .= " AND (SELECT COUNT(*) FROM (SELECT user_id FROM enswitch_new_iphone_purchases
                                                    UNION
                                                  SELECT user_id FROM enswitch_new_android_purchases) AS p WHERE `status` > 0 AND user_id` = `musers`.`id`) >= :value".$value_counter;
                    $values[$value_counter] = $cnd['value'];
                    break;
// REALLY SLOW SUB-QUERY:
                case 'never_purchase':
                    // Here I am trying to CUT the users by subquery to get only the users who never made a puchase.
                    $sql .= ' AND (SELECT COUNT(*) FROM (SELECT user_id FROM enswitch_new_iphone_purchases
                                                    UNION
                                                  SELECT user_id FROM enswitch_new_android_purchases) AS p WHERE `status` = 0 AND `user_id` = `musers`.`id`) = 0';
                    break;
            }
        }


        $query = DB::query(Database::SELECT, $sql);
        $query->bind(':mobile_type', $mobile_type);
        // Looping the values and binding it into the SQL query!
        foreach ($values as $k => $v) {
            $query->bind(':value'.$k, $values[$k]);
        }
        // Executing query
        $result = $query->execute();
        return array('total_users' =>$result[0]['total'], 'affected_users'=>$result[0]['users']);
    }

编辑： 请求的最慢查询：（MySQL）

---

第二个

SELECT

列中的子查询将对通过

其中

条件的每个

MU用户

行执行：

SELECT
  COUNT(*) AS users,
  (SELECT COUNT(*) FROM enswitch_mobile_users) AS total <-- here's the problem
FROM enswitch_mobile_users AS musers
WHERE musers.phone_type = whatever

---

CASE

检查电话类型，如果它与您感兴趣的电话类型匹配，则会生成一个

1

，并将其计算在内。如果不匹配，它将生成一个

NULL

，该值不被计算。

因为这不是一个真正的php问题，如果您只发布生成的sql语句，它可能会更有用，更容易阅读。显示生成的查询和数据库架构。并显示问题查询的解释，以查看索引（如果有）它实际上是在使用。每行运行一个子查询基本上是让事情变得疯狂缓慢的最佳方式。

SELECT
  COUNT(*) AS users,
  (SELECT COUNT(*) FROM enswitch_mobile_users) AS total <-- here's the problem
FROM enswitch_mobile_users AS musers
WHERE musers.phone_type = whatever

SELECT
  COUNT(CASE WHEN musers.phone_type = whatever THEN 1 END) AS users,
  COUNT(*) AS total
FROM enswitch_mobile_users