將多個計數/組查詢合並為一條語句

Question

我一直在研究一種為多個表中的用戶返回計數的方法。

<?php

    $stmt = $db->prepare("SELECT `computer_username`, `computer_name`, COUNT(`computer_name`) `totalsum` FROM `table1`
        WHERE `account_id` = ? AND (`computer_name` = 'comp1' OR `computer_name` = 'comp2' OR `computer_name` = 'comp3')
        GROUP BY `computer_username`, `computer_name`
    ");

    $stmt->execute(array($_SESSION['user']['account_id']));
    $results = $stmt->fetchAll(PDO::FETCH_ASSOC);   
    //print out the array
    echo 'table1<br /><pre>',print_r($results,true),'</pre><br /><br />';

    $stmt = $db->prepare("SELECT `computer_username`, `computer_name`, COUNT(`computer_name`) `totalsum` FROM `table2`
        WHERE `account_id` = ? AND (`computer_name` = 'comp1' OR `computer_name` = 'comp2' OR `computer_name` = 'comp3')
        GROUP BY `computer_username`, `computer_name`
    ");

    $stmt->execute(array($_SESSION['user']['account_id']));
    $results = $stmt->fetchAll(PDO::FETCH_ASSOC);   
    //print out the array
    echo 'table2<br /><pre>',print_r($results,true),'</pre><br /><br />';

    $stmt = $db->prepare("SELECT `computer_username`, `computer_name`, COUNT(`computer_name`) `totalsum` FROM `table3`
        WHERE `account_id` = ? AND (`computer_name` = 'comp1' OR `computer_name` = 'comp2' OR `computer_name` = 'comp3')
        GROUP BY `computer_username`, `computer_name`
    ");

    $stmt->execute(array($_SESSION['user']['account_id']));
    $results = $stmt->fetchAll(PDO::FETCH_ASSOC);   
    //print out the array
    echo 'table3<br /><pre>',print_r($results,true),'</pre><br /><br />';

?>

對於每個數組，結果類似於以下內容：

Array
(
    [0] => Array
        (
            [computer_username] => Bob
            [computer_name] => comp1
            [totalsum] => 1
        )

    [1] => Array
        (
            [computer_username] => Steve
            [computer_name] => comp1
            [totalsum] => 27
        )

    [2] => Array
        (
            [computer_username] => Sue
            [computer_name] => comp2
            [totalsum] => 7
        )

)

我只是想返回數據庫中每個表的每個組的總行數。 由於條件完全相同且僅表名不同，是否有一種方法可以在一次調用中返回全部內容？ 我整天都在玩它，但是到目前為止，對每個查詢使用查詢是我獲得結果的唯一方法。

理想情況下，我正在尋找一個類似以下內容的數組結果：

Array
(
    [0] => Array
        (
            [computer_username] => Bob
            [computer_name] => comp1
            [table1] => 15
            [table2] => 34
            [table3] => 131
        )

        ... and so on for each computer_name/computer_username group

)

編輯：

我在這方面取得了一些進展...

SELECT * FROM

(SELECT computer_name, username, COUNT(computer_name) usercount
FROM users
WHERE `account_id` = ?
GROUP BY `username`, `computer_name`) a

JOIN 

(SELECT computer_name, computer_username, COUNT(computer_name) t1count
FROM t1
WHERE `account_id` = ?
GROUP BY `computer_username`, `computer_name`) b

JOIN

(SELECT computer_name, computer_username, COUNT(computer_name) t2count
FROM t2
WHERE `account_id` = ?
GROUP BY `computer_username`, `computer_name`) c

JOIN

(SELECT computer_name, computer_username, COUNT(computer_name) t3count
FROM t3
WHERE `account_id` = ?
GROUP BY `computer_username`, `computer_name`) d

ON a.username = b.computer_username AND a.username = c.computer_username AND a.username = d.computer_username

我從users表開始，因為它將始終列出所有用戶名/計算機組的組合。 問題在於，要在數組中返回的任何結果，用戶名/計算機組也必須在每個其他表中都包含條目（t1，t2，t3）。

可以這么說，在computer1上的Bob在t1中有5行，在t2中有10行，在t3中有50行，我將把這些計數以t1count，t2count，t3count的形式返回到我的數組中。 在computer4上的Sue在t1、0和t2中具有5，在t3中具有12 ...因為t2中沒有行，所以不會返回她的任何結果。

有什么辦法解決這個問題，或者聯接是否明確要求從一個表到另一個表的匹配值？

示例數據和預期結果：

假設上面的所有表都有一個名為account_id = 1的列。您有一個account_id，它代表計算機的“所有者”。 用戶是所有計算機以及這些計算機上所有用戶名的表。 table1，table2，table3是與特定計算機和該計算機的特定用戶相關聯的記錄。 在那些表中的任何特定用戶/計算機對都可以有零個記錄或任何數量的記錄。

目標是在給定一個account_id和computer_name列表的情況下，為每個用戶返回記錄表（table1，table2，table3）的計數。 無需對結果進行任何排序。

Answer 1

使用提供的數據並且不提供要查詢的ID即可完成您想要的操作。 看到工作FIDDLE

SELECT 
  usr, 
  cmptr, 
  t1_count, 
  t2_count, 
  t3_count 
FROM (
  SELECT
    users.username AS usr,
    users.computer_name AS cmptr,
    count(t1.computer_name) AS t1_count
  FROM users
  JOIN t1 ON t1.computer_username = users.username AND t1.computer_name = users.computer_name
  GROUP BY users.username, users.computer_name
)AS t
LEFT JOIN(
  SELECT
    users.username,
    users.computer_name,
    count(t2.computer_name) AS t2_count
  FROM users
  JOIN t2 ON t2.computer_username = users.username AND t2.computer_name = users.computer_name
  GROUP BY users.username, users.computer_name
) AS te ON te.username = t.usr OR te.computer_name = t.cmptr
LEFT JOIN(
  SELECT
    users.username,
    users.computer_name,
    count(t3.computer_name) AS t3_count
  FROM users
  JOIN t3 ON t3.computer_username = users.username AND t3.computer_name = users.computer_name
  GROUP BY users.username, users.computer_name
) AS tem ON tem.username = t.usr OR tem.computer_name = t.cmptr
GROUP BY usr, cmptr

將多個計數/組查詢合並為一條語句

問題描述

1 個解決方案

解決方案1
1 已采納 2014-05-06 01:09:37

將多個計數/組查詢合並為一條語句

問題描述

1 個解決方案

解決方案1 1 已采納 2014-05-06 01:09:37

解決方案1
1 已采納 2014-05-06 01:09:37