Laravel 3 中的复杂 sql 语句

Question

这是我目前的代码

    $piv0 = "SET @pivot_query = NULL;";
    $piv1 = "SELECT GROUP_CONCAT(DISTINCT CONCAT('MAX(IF(custom_field = \"\"',custom_field,\"\"', cf_values, NULL)) AS ',custom_field)) INTO @pivot_query FROM custom_fields_values; ";

    $piv2 = "SET @pivot = CONCAT('SELECT subscriber_id, ', @pivot_query, ' FROM custom_fields_values GROUP BY subscriber_id');";

    $piv3 = "SET @sql = CONCAT('SELECT * FROM user_data_3 LEFT JOIN (',@pivot,') piv ON user_data_5.aw_id = piv.subscriber_id');";
    $piv4 = "PREPARE stmt FROM @sql; ";
    $piv5 = "EXECUTE stmt;";
    $piv6 = "DEALLOCATE PREPARE stmt;";

    $db = DB::connection()->pdo;
    $db->setAttribute(PDO::MYSQL_ATTR_USE_BUFFERED_QUERY, true);

    $query = $db->prepare($piv0);
    $query->execute();

    $query = $db->prepare($piv1);
    $query->execute();

    $query = $db->prepare($piv2);
    $query->execute();

    $query = $db->prepare($piv3);
    $query->execute();

    $query = $db->prepare($piv4);
    $query->execute();

    $query = $db->prepare($piv5);
    $query->execute();

    $query = $db->prepare($piv6);
    $query->execute();

    $result = $query->fetchAll();

但是，我收到了错误：

General error: 2014 Cannot execute queries while other unbuffered queries are active.  Consider using PDOStatement::fetchAll().  Alternatively, if your code is only ever going to run against mysql, you may enable query buffering by setting the PDO::MYSQL_ATTR_USE_BUFFERED_QUERY attribute.

我查看了其他一些 SO 问题，有人提到 $query->fetchAll() 和/或 $query->closeCursor() 应该有帮助，但他们在这里没有帮助我。

我在$query = $db->prepare($piv4); 收到错误

我还应该尝试什么？

Answer 1

我想出了一个解决方法：

$middleQueryRes = DB::query("SELECT GROUP_CONCAT(DISTINCT CONCAT('MAX(IF(custom_field =''', custom_field,''', cf_values, NULL)) AS ',custom_field)) FROM custom_fields_values;");
foreach ($middleQueryRes[0] as $value) {
   $middleQueryRes = $value
   break;
 }

$middleQuery2 = "SELECT subscriber_id, $middleQueryRes FROM custom_fields_values GROUP BY subscriber_id";

$finalRes = DB::query("SELECT * FROM user_data_3 LEFT JOIN ($middleQuery2) piv ON user_data_5.aw_id = piv.subscriber_id");

Answer 2

您正在执行部分或一个查询，而您应该通过. 添加它们。尝试像那样执行它们。

$piv = "SET @pivot_query = NULL;";
$piv .= "SELECT GROUP_CONCAT(DISTINCT CONCAT('MAX(IF(custom_field = \"\"',custom_field,\"\"', cf_values, NULL)) AS ',custom_field)) INTO @pivot_query FROM custom_fields_values; ";

$piv .= "SET @pivot = CONCAT('SELECT subscriber_id, ', @pivot_query, ' FROM custom_fields_values GROUP BY subscriber_id');";

$piv .= "SET @sql = CONCAT('SELECT * FROM user_data_3 LEFT JOIN (',@pivot,') piv ON user_data_5.aw_id = piv.subscriber_id');";
$piv .= "PREPARE stmt FROM @sql; ";
$piv .= "EXECUTE stmt;";
$piv .= "DEALLOCATE PREPARE stmt;";  
 $db = DB::connection()->pdo;

$query = $db->prepare($piv);
$query->execute();
$result = $query->fetchAll();

编辑：

 $piv = "SET @pivot_query = NULL;
         SELECT GROUP_CONCAT(DISTINCT CONCAT('MAX(IF(custom_field = \"\"',custom_field,\"\"', cf_values, NULL)) AS ',custom_field)) INTO @pivot_query FROM custom_fields_values; 
         SET @pivot = CONCAT('SELECT subscriber_id, ', @pivot_query, ' FROM custom_fields_values GROUP BY subscriber_id');
         SET @sql = CONCAT('SELECT * FROM user_data_3 LEFT JOIN (',@pivot,') piv ON user_data_5.aw_id = piv.subscriber_id');
         PREPARE stmt FROM @sql; 
         EXECUTE stmt;
         DEALLOCATE PREPARE stmt;";