PDO查詢不起作用

Question

我已經看了幾個小時的相同代碼，試圖找出爲什麼我的查詢不起作用。我下面列出的兩個是不工作的兩個。

$getRequestIdQuery = "SELECT request_id 
    FROM request_table 
    WHERE request_key = '$requestKey' 
    AND sort_order = $so"; 

$getRequestId = $pdo->prepare($getRequestIdQuery); 
$getRequestId->execute(); 
foreach($getRequestId as $idRow) 
{ 
    $requestId = $idRow['request_id']; 
} 

// This will update the ready status of the request id returned above 
$updateReadyStatusQuery = "UPDATE request_table 
    SET request_ready = 1 
    WHERE request_id = $requestId"; 
$updateReadyStatus = $pdo->prepare($updateReadyStatusQuery); 
$updateReadyStatus->execute(); 

上述情況在文件副本返回true時運行。我已經確定這是在運行，因爲在每次測試運行期間都會顯示上面的錯誤日誌。我也確定有問題的查詢工作正常，因爲我在phpmyadmin中成功運行了查詢（如錯誤日誌中顯示的那樣）。以下是上面的代碼只有這幾行代碼，可運行正常：

$checkForComposedQuery = "SELECT * 
    FROM composed_files 
    WHERE file_source_id = '$fsi' 
    AND file_number = '$fn'"; 

$checkForComposed = $pdo->prepare($checkForComposedQuery); 
$checkForComposed->execute(); 

任何提示，以什麼可能會導致這不行？如果有幫助，上述兩個片段都在foreach循環中發生。

非常感謝提前。

UPDATE：

下結合的代碼，其中包括由以下查爾斯補充建議：

$gotCopied = copy($sourceHymnFile, $destHymnFile); 

if ($gotCopied == true) { 
    error_log("The file has been successfully copied."); 

    $idRow; 
    $getRequestIdQuery = "SELECT request_id 
     FROM request_table 
     WHERE request_key = ? 
     AND sort_order = ?"; 
    $getRequestId = $pdo->prepare($getRequestIdQuery); 
    $getRequestId->execute(array($requestKey, $so)); 
    error_log("this is the value of request key : ".$requestKey); 
    // Displays correct $requestKey value 
    error_log("This is the value of sort order : ".$so); 
    // Displays correct $so value 
    $idRow = $getRequestId->fetch(PDO::FETCH_ASSOC); 
    $requestId = $idRow['request_id']; 
    error_log("This is the value of the request id : ".$requestId); 
    // No output in error log for $requestId above 

    // This will update the ready status of the request id returned above 
    $updateReadyStatusQuery = "UPDATE request_table 
     SET ready = 1 
     WHERE request_id = ?"; 
    error_log("This updates the status of the song request if the song is played : ".$updateReadyStatusQuery); 
    $updateReadyStatus = $pdo->prepare($updateReadyStatusQuery); 
    $updateReadyStatus->execute(array($requestId)); 
} 

以下爲進入正常運行正常常量：

if ($gotCopied == true) { 
    error_log("The file has been successfully copied."); 

    $idRow; 
    $getRequestIdQuery = "SELECT request_id 
     FROM request_table 
     WHERE request_key = ? 
     AND sort_order = ?"; 
    $getRequestId = $pdo->prepare($getRequestIdQuery); 
    $getRequestId->execute(array(5, 2)); 
    error_log("this is the value of request key : ".$requestKey); 
    error_log("This is the value of sort order : ".$so); 
    $idRow = $getRequestId->fetch(PDO::FETCH_ASSOC); 
    $requestId = $idRow['request_id']; 
    error_log("This is the value of the request id : ".$requestId); 
    // No output in error log for $requestId above 

    // This will update the ready status of the request id returned above 
    $updateReadyStatusQuery = "UPDATE request_table 
     SET ready = 1 
     WHERE request_id = ?"; 
    error_log("This updates the status of the song request if the song is played : ".$updateReadyStatusQuery); 
    $updateReadyStatus = $pdo->prepare($updateReadyStatusQuery); 
    // This execute works correctly if a value is set for $requestId 
    $updateReadyStatus->execute(array($requestId)); 
} 

Answer 1

你有兩個問題這裏。

首先，佔位符和綁定。你的代碼很容易被SQL注入。 PDO包含一個工具來幫助減輕這種威脅。

$getRequestIdQuery = "SELECT request_id 
    FROM request_table 
    WHERE request_key = ? -- new! 
    AND sort_order = ?"; 

$getRequestId = $pdo->prepare($getRequestIdQuery); 
$getRequestId->execute(array($requestKey, $so)); 

查詢中的?是佔位符。傳遞給execute的數組提供了任何佔位符的替換列表。它們會根據需要自動轉義並引用。

其次，您檢索結果不正確。您需要在語句句柄上調用fetch method（或fetchAll method）。例如：

$idRow = $getRequestId->fetch(PDO::FETCH_ASSOC); 
$requestId = $idRow['request_id']; 

請注意，這裏沒有循環。你以前的循環會預期有多個結果，但它會在每個循環中重寫相同的變量。看起來你只需要一個結果，所以你只需要擔心一個結果。

我們還應該更新您的其他查詢以使用佔位符。

$updateReadyStatusQuery = "UPDATE request_table 
    SET request_ready = 1 
    WHERE request_id = ?"; 
$updateReadyStatus = $pdo->prepare($updateReadyStatusQuery); 
$updateReadyStatus->execute(array($requestId)); 

...和你的第三個......

$checkForComposedQuery = "SELECT * 
    FROM composed_files 
    WHERE file_source_id = ? 
    AND file_number = ?"; 

$checkForComposed = $pdo->prepare($checkForComposedQuery); 
$checkForComposed->execute(array($fsi, $fn));