檢索數據庫的結果與JOIN

Question

我試圖函數的操作的數量減少到只有一個查詢，但現在我無法檢索到任何結果：

function retrive_avaible_operator($Hostname, $Username, $Password, $DatabaseName, $SupportUserPerDepaTable, $SupportUserTable,$dep){ 
    $query = "SELECT b.id 
       FROM ".$SupportUserTable." b 
       INNER JOIN ".$SupportUserPerDepaTable." a 
        ON b.id=a.user_id 
       WHERE a.department_id=? AND b.holiday='0' AND a.user_id!=".$_SESSION['id']." 
       ORDER BY b.assigned_tickets ASC LIMIT 1"; 

    $mysqli = new mysqli($Hostname, $Username, $Password, $DatabaseName); 
    $stmt = $mysqli->stmt_init(); 
    $prepared = $stmt->prepare($query); 

    if($prepared){ 
     if($stmt->bind_param('i', $dep)){ 
      if($stmt->execute()){ 
       $stmt->store_result(); 
       $result = $stmt->bind_result($camaro); 
       if($stmt->num_rows>0){ 
        while (mysqli_stmt_fetch($stmt)) 
         $selopid=$camaro; 
        return $selopid; 
       } 
       else 
        return 'No Operator Available'; 
      } 
      else 
       return mysqli_stmt_error($stmt); 
     } 
     else 
      return mysqli_stmt_error($stmt); 
    } 
    else 
     return mysqli_stmt_error($stmt); 
} 

在此之前嘗試的操作是（這些是2個不同的查詢）：

1. 從$SupportUserPerDepaTable選擇所有id其中a.department_id=?
2. 從$SupportUserTable選擇所有id其中id是previo內部我們的結果和holiday='0'

它的工作，但現在它只返回No Operator Available

而且這些都是表：

CREATE TABLE IF NOT EXISTS `razorphyn_support_user_departments` (
`id`    BIGINT(11) UNSIGNED NOT NULL AUTO_INCREMENT, 
`department_id`  BIGINT(11) UNSIGNED NOT NULL, 
`department_name` VARCHAR(70)    NOT NULL, 
`user_id`   BIGINT(11) UNSIGNED NOT NULL, 
`holiday`   ENUM('0','1')   NOT NULL DEFAULT '0', 
PRIMARY KEY (`id`), 
UNIQUE KEY(`department_name`,`user_id`), 
INDEX(`department_id`,`department_name`,`user_id`) 
) ENGINE=MyISAM DEFAULT CHARSET=utf8 AUTO_INCREMENT=0; 

和

CREATE TABLE IF NOT EXISTS `razorphyn_support_users` (
`id`    BIGINT(15)  UNSIGNED  NOT NULL AUTO_INCREMENT, 
`name`    VARCHAR(50)      NOT NULL, 
`mail`    VARCHAR(50)      NOT NULL, 
`password`   VARCHAR(200)     NOT NULL, 
`reg_key`   VARCHAR(260)     , 
`tmp_password`  VARCHAR(87)      , 
`ip_address`  VARCHAR(50)      NOT NULL, 
`status`   ENUM('0','1','2','3','4')  NOT NULL DEFAULT '3', 
`holiday`   ENUM('0','1')     NOT NULL DEFAULT '0', 
`mail_alert`  ENUM('no','yes')    NOT NULL DEFAULT 'yes', 
`assigned_tickets` INT(5)   UNSIGNED  NOT NULL DEFAULT 0, 
`solved_tickets` BIGINT(11)  UNSIGNED  NOT NULL DEFAULT 0, 
`number_rating`  BIGINT(6)  UNSIGNED  NOT NULL DEFAULT 0, 
`rating`   DECIMAL(4,2) UNSIGNED  NOT NULL DEFAULT 0, 
PRIMARY KEY (`id`), 
UNIQUE KEY(`mail`), 
INDEX (`name`,`mail`,`status`,`holiday`,`assigned_tickets`,`solved_tickets`) 
) ENGINE=MyISAM DEFAULT CHARSET=utf8 AUTO_INCREMENT=55; 

編輯
我發現（不幸的是，怎麼一回事，因爲是很醜陋和雜亂）前面的代碼（我已刪除了所有的控制，如果，但它的工作原理）：

function retrive_avaible_operator($Hostname, $Username, $Password, $DatabaseName, $SupportUserPerDepaTable, $SupportUserTable,$dep){ 

$query = "SELECT `user_id` FROM ".$SupportUserPerDepaTable." WHERE `department_id`=? AND `user_id`!=".$_SESSION['id'] ; 
$mysqli = new mysqli($Hostname, $Username, $Password, $DatabaseName); 
$stmt = $mysqli->stmt_init(); 
$prepared = $stmt->prepare($query); 
    $stmt->bind_param('i', $dep) 
     $stmt->execute() 
      $stmt->store_result(); 
      $operator=array(); 
      $result = $stmt->bind_result($camaro); 
      if($stmt->num_rows>0){ 
       while (mysqli_stmt_fetch($stmt)) 
        $operator[]=$camaro; 
       $operator=join(',',$operator); 
       $query = "SELECT `id` FROM ".$SupportUserTable." WHERE `id` IN (".$operator.") AND `holiday`='0' ORDER BY `assigned_tickets` ASC LIMIT 1" ; 
       $prepared = $stmt->prepare($query); 
       $prepared) 
        $stmt->execute() 
         $stmt->store_result(); 
         $result = $stmt->bind_result($camaro); 
         if($stmt->num_rows>0){ 
          while (mysqli_stmt_fetch($stmt)) 
           $selopid=$camaro; 
          return $selopid; 
         } 
         else{ 
          $query = "SELECT `id` FROM ".$SupportUserTable." WHERE `status`=2 AND `holiday`=0 AND `id`!=".$_SESSION['id']." ORDER BY `assigned_tickets` ASC, `solved_tickets` ASC LIMIT 1" ; 
          $prepared = $stmt->prepare($query); 
          $prepared 
           $stmt->execute() 
            $stmt->store_result(); 
            $result = $stmt->bind_result($camaro); 
            if($stmt->num_rows>0){ 
             while (mysqli_stmt_fetch($stmt)) 
              $selopid=$camaro; 
             return $selopid; 
            } 
            else 
             return 'No Operator Available'; 
         } 
      } 
      else{ 
       $query = "SELECT `id` FROM ".$SupportUserTable." WHERE `status`='2' AND `holiday`='0' AND `id`!=".$_SESSION['id']." ORDER BY `assigned_tickets` ASC, `solved_tickets` ASC LIMIT 1" ; 
       $prepared = $stmt->prepare($query); 
        $stmt->execute() 
         $stmt->store_result(); 
         $result = $stmt->bind_result($camaro); 
         if($stmt->num_rows>0){ 
          while (mysqli_stmt_fetch($stmt)) 
           $selopid=$camaro; 
          return $selopid; 
         } 
         else 
          return 'No Operator Available'; 
      } 
$mysqli->close(); 
} 

Answer 1

你應該能夠大大凝結這一點。在開始時，您只需查詢$SupportUserPerDepaTable即可獲取user_id，僅用於將它們加入第二個查詢的逗號分隔字符串中。您應該能夠通過將其轉換爲子查詢來消除此問題。第3個和第4個查詢是多餘的，這是前一個if/else情況的一個結果，所以你可以結合那些現在已經消除了top條件的情況。使用底部「醜」代碼，我它冷凝以這樣的：

$mysqli = new mysqli($Hostname, $Username, $Password, $DatabaseName); 
$stmt = $mysqli->stmt_init(); 
$query = " 
SELECT  `id` 
FROM  ".$SupportUserTable." 
WHERE  `id` IN (
    SELECT  `user_id` 
    FROM  ".$SupportUserPerDepaTable." 
    WHERE  `department_id`= ? 
    AND   `user_id`!=".$_SESSION['id']." 
) 
AND   `holiday`='0' 
ORDER BY `assigned_tickets` ASC 
LIMIT  1" ; 

$prepared = $stmt->prepare($query); 
$stmt->bind_param('i', $dep); 
$stmt->execute(); 
$stmt->store_result(); 
$operator=array(); 
$result = $stmt->bind_result($camaro); 
if($stmt->num_rows>0){ 
    while (mysqli_stmt_fetch($stmt)) 
     $selopid=$camaro; 
    return $selopid; 
} 
else{ 
    $query = " 
    SELECT  `id` 
    FROM  ".$SupportUserTable." 
    WHERE  `status`= 2 
    AND   `holiday`=0 
    AND   `id`!=".$_SESSION['id']." 
    ORDER BY `assigned_tickets` ASC 
       ,`solved_tickets` ASC 
    LIMIT  1" ; 
    $prepared = $stmt->prepare($query); 
    $stmt->execute(); 
    $stmt->store_result(); 
    $result = $stmt->bind_result($camaro); 
    if($stmt->num_rows>0){ 
     while (mysqli_stmt_fetch($stmt)) 
      $selopid=$camaro; 
     return $selopid; 
    } 
    else{ 
     return 'No Operator Available'; 
    } 
} 
$mysqli->close(); 

您可以進一步通過使用UNION具有1像的組合限制所述2次的查詢凝結成1：

(
    SELECT  `id` 
    FROM  ".$SupportUserTable." 
    WHERE  `id` IN (
     SELECT  `user_id` 
     FROM  ".$SupportUserPerDepaTable." 
     WHERE  `department_id`= ? 
     AND   `user_id`!=".$_SESSION['id']." 
    ) 
    AND   `holiday`='0' 
    ORDER BY `assigned_tickets` ASC 
    UNION 
    SELECT  `id` 
     FROM  ".$SupportUserTable." 
     WHERE  `status`= 2 
     AND   `holiday`=0 
     AND   `id`!=".$_SESSION['id']." 
     ORDER BY `assigned_tickets` ASC 
        ,`solved_tickets` ASC 
) 
LIMIT  1; 

或可能使用OR條件取決於dept表像一個僱員的身份代碼：

SELECT  `id` 
FROM  ".$SupportUserTable." 
WHERE  `holiday`='0' 
AND (  
     `id` IN (
      SELECT  `user_id` 
      FROM  ".$SupportUserPerDepaTable." 
      WHERE  `department_id`= ? 
      AND   `user_id`!=".$_SESSION['id']." 
     ) 
     AND  `status`= ('some code other than 2?') 
    ) 
    OR (
       `status`= 2 
     AND  `id`! = ".$_SESSION['id']." 
) 
ORDER BY status (asc or desc?) 
      ,`assigned_tickets` ASC 
      ,`solved_tickets` ASC 
LIMIT  1; 

我還沒有測試這個，因爲這將花費太多時間來設置建立數據庫表，輸入樣本數據並全部測試，所以如果有任何小錯誤，請原諒我，但這應該指向正確的方向。如果這不起作用，你想發佈一些示例數據到http://sqlfiddle.com/，並給出一些預期輸出的例子，我會重試一些查詢，看看我能做些什麼。