[英]PHP PDO - Using MySQL Variables
我正在嘗試使用 PDO 在 PHP 中運行查詢。 查詢在頂部有一些變量來確定排名,除了在 $sql 中使用 SET @var 時,它返回一個空行集。 但是,如果我刪除了有問題的 SQL,它會返回正常。
我不想在我的腳本中返回 @prev_value、@rank_count 或 @rank_increasing,只返回它在 SELECT 中創建的排名。
你能告訴我我做錯了什么嗎?
謝謝
$sql = "
SET @prev_value = NULL;
SET @rank_count = 0;
SET @rank_increasing = 0;
SELECT a.*
, @rank_increasing := @rank_increasing + 1 AS row_num
, CASE
WHEN @prev_value = score
THEN @rank_count
WHEN @prev_value := score
THEN @rank_count := @rank_increasing
END AS rank
FROM (
-- INLINE VIEW --
) a
";
try {
$sth = $dbh->prepare($sql);
$sth->execute(array($var1, $var2));
return $sth->fetchAll(PDO::FETCH_ASSOC);
} catch (Exception $e) {
return $e;
}
在這里找到解決方案: https : //stackoverflow.com/a/4685040/1266457
謝謝 :)
修理:
// Prepare and execute the variables first
$sql = "
SET @prev_value = NULL;
SET @rank_count = 0;
SET @rank_increasing = 0;
";
$sth = $dbh->prepare($sql);
$sth->execute();
// Run the main query
$sql = "
SELECT a.*
, @rank_increasing := @rank_increasing + 1 AS row_num
, CASE
WHEN @prev_value = score
THEN @rank_count
WHEN @prev_value := score
THEN @rank_count := @rank_increasing
END AS rank
FROM (
-- INLINE VIEW --
) a
"; ...
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