如何防止MySQL使用PDO用空字符串更新列

Question

我有確切的問題，如我如何防止MySQL用空字符串更新列

但是，唯一的不足是我將其應用於PDO而不是常規的MySQL。

我已遵循有關添加IF語句以檢查長度是否為0的問題的最高答案。這似乎不適用於PDO，但是由於表和網頁輸出未發生更新，因此： Array ( [0] => HY093 [1] => [2] => ) 1 。 注意我通過綁定函數使用准備好的語句。

我的帶有IF語句的PHP代碼包括：

    <?php
$pdo=new PDO("mysql:dbname=createyo_TestDatabase;host=localhost","createyo_james","password");

$statement=$pdo->prepare(
"UPDATE `Users` 
SET `EditIDs` = IF(LENGTH(':EditID')=0, EditIDs, ':EditID'), 
`ArticleIDs` = IF(LENGTH(':ArticleID')=0, ArticleIDs, ':ArticleID'),
`Reputation` = IF(LENGTH(':Reputation')=0, Reputation, ':Reputation'),
`VotedUpArticleIDs` = IF(LENGTH(':VotedUpArticleID')=0, VotedUpArticleIDs, ':VotedUpArticleID'),
`VotedUpEditIDs` = IF(LENGTH(':VotedUpEditID')=0, VotedUpEditIDs, ':VotedUpEditID'),
`VotedDownArticleIDs` = IF(LENGTH(':VotedDownArticleID')=0, VotedDownArticleIDs, ':VotedDownArticleID'),
`VotedDownEditIDs` = IF(LENGTH(':VotedDownEditID')=0, VotedDownEditIDs, ':VotedDownEditID'),
WHERE `UserID` = :UserID");

$statement->bindValue(':EditID', (string) trim($_GET['EditID']), PDO::PARAM_STR);
$statement->bindValue(':ArticleID', (string) trim($_GET['ArticleID']), PDO::PARAM_STR);
$statement->bindValue(':Reputation', (string) trim($_GET['Reputation']), PDO::PARAM_STR);
$statement->bindValue(':VotedUpArticleID', (string) trim($_GET['VotedUpArticleID']), PDO::PARAM_STR);
$statement->bindValue(':VotedUpEditID', (string) trim($_GET['VotedUpEditID']), PDO::PARAM_STR);
$statement->bindValue(':VotedDownArticleID', (string) trim($_GET['VotedDownArticleID']), PDO::PARAM_STR);
$statement->bindValue(':VotedDownEditID', (string) trim($_GET['VotedDownEditID']), PDO::PARAM_STR);

    $statement->bindValue(':UserID', (string) trim($_GET['UserID']), PDO::PARAM_STR);

    $statement->execute() or die(print_r($statement->errorInfo()));
$results=$statement->fetchAll(PDO::FETCH_ASSOC);
$json=json_encode($results);
print $json;
?>

編輯

我現在收到語法錯誤：SQL語法有錯誤； 請查看與您的MySQL服務器版本相對應的手冊，以在第9行的'WHERE UserID ='1234'附近使用正確的語法。我無法理解此錯誤。

新的PHP代碼：

$statement=$pdo->prepare(
"UPDATE `Users` 
SET `EditIDs` = IF(LENGTH(:EditID)=0, EditIDs, :EditID1), 
`ArticleIDs` = IF(LENGTH(:ArticleID)=0, ArticleIDs, :ArticleID1),
`Reputation` = IF(LENGTH(:Reputation)=0, Reputation, :Reputation1),
`VotedUpArticleIDs` = IF(LENGTH(:VotedUpArticleID)=0, VotedUpArticleIDs, :VotedUpArticleID1),
`VotedUpEditIDs` = IF(LENGTH(:VotedUpEditID)=0, VotedUpEditIDs, :VotedUpEditID1),
`VotedDownArticleIDs` = IF(LENGTH(:VotedDownArticleID)=0, VotedDownArticleIDs, :VotedDownArticleID1),
`VotedDownEditIDs` = IF(LENGTH(:VotedDownEditID)=0, VotedDownEditIDs, :VotedDownEditID1),
WHERE `UserID` = :UserID");
$statement->bindValue(':EditID', (string) trim($_GET['EditID']), PDO::PARAM_STR);
$statement->bindValue(':ArticleID', (string) trim($_GET['ArticleID']), PDO::PARAM_STR);
    $statement->bindValue(':Reputation', (string) trim($_GET['Reputation']), PDO::PARAM_STR);
$statement->bindValue(':VotedUpArticleID', (string) trim($_GET['VotedUpArticleID']), PDO::PARAM_STR);
$statement->bindValue(':VotedUpEditID', (string) trim($_GET['VotedUpEditID']), PDO::PARAM_STR);
$statement->bindValue(':VotedDownArticleID', (string) trim($_GET['VotedDownArticleID']), PDO::PARAM_STR);
$statement->bindValue(':VotedDownEditID', (string) trim($_GET['VotedDownEditID']), PDO::PARAM_STR);

$statement->bindValue(':EditID1', (string) trim($_GET['EditID']), PDO::PARAM_STR);
$statement->bindValue(':ArticleID1', (string) trim($_GET['ArticleID']), PDO::PARAM_STR);
$statement->bindValue(':Reputation1', (string) trim($_GET['Reputation']), PDO::PARAM_STR);
$statement->bindValue(':VotedUpArticleID1', (string) trim($_GET['VotedUpArticleID']), PDO::PARAM_STR);
$statement->bindValue(':VotedUpEditID1', (string) trim($_GET['VotedUpEditID']), PDO::PARAM_STR);
$statement->bindValue(':VotedDownArticleID1', (string) trim($_GET['VotedDownArticleID']), PDO::PARAM_STR);
$statement->bindValue(':VotedDownEditID1', (string) trim($_GET['VotedDownEditID']), PDO::PARAM_STR);

Answer 1

在SQL中，不應將:placeholder放在引號內。 這使它們成為文字字符串，因此不會從綁定參數中替換它們。

$statement=$pdo->prepare(
"UPDATE `Users` 
SET `EditIDs` = IF(LENGTH(:EditID)=0, EditIDs, :EditID), 
`ArticleIDs` = IF(LENGTH(:ArticleID)=0, ArticleIDs, :ArticleID),
`Reputation` = IF(LENGTH(:Reputation)=0, Reputation, :Reputation),
`VotedUpArticleIDs` = IF(LENGTH(:VotedUpArticleID)=0, VotedUpArticleIDs, :VotedUpArticleID),
`VotedUpEditIDs` = IF(LENGTH(:VotedUpEditID)=0, VotedUpEditIDs, :VotedUpEditID),
`VotedDownArticleIDs` = IF(LENGTH(:VotedDownArticleID)=0, VotedDownArticleIDs, :VotedDownArticleID),
`VotedDownEditIDs` = IF(LENGTH(:VotedDownEditID)=0, VotedDownEditIDs, :VotedDownEditID),
WHERE `UserID` = :UserID");

但是，您也不允許在同一查詢中多次使用相同的:placeholder 。 因此，您需要為重復的占位符賦予不同的名稱。

$statement=$pdo->prepare(
"UPDATE `Users` 
SET `EditIDs` = IF(LENGTH(:EditID)=0, EditIDs, :EditID1), 
`ArticleIDs` = IF(LENGTH(:ArticleID)=0, ArticleIDs, :ArticleID1),
`Reputation` = IF(LENGTH(:Reputation)=0, Reputation, :Reputation1),
`VotedUpArticleIDs` = IF(LENGTH(:VotedUpArticleID)=0, VotedUpArticleIDs, :VotedUpArticleID1),
`VotedUpEditIDs` = IF(LENGTH(:VotedUpEditID)=0, VotedUpEditIDs, :VotedUpEditID1),
`VotedDownArticleIDs` = IF(LENGTH(:VotedDownArticleID)=0, VotedDownArticleIDs, :VotedDownArticleID1),
`VotedDownEditIDs` = IF(LENGTH(:VotedDownEditID)=0, VotedDownEditIDs, :VotedDownEditID1)
WHERE `UserID` = :UserID");

然后，您必須綁定所有其他參數：

$statement->bindValue(':EditID1', (string) trim($_GET['EditID']), PDO::PARAM_STR);
$statement->bindValue(':ArticleID1', (string) trim($_GET['ArticleID']), PDO::PARAM_STR);
$statement->bindValue(':Reputation', (string) trim($_GET['Reputation']), PDO::PARAM_STR);
$statement->bindValue(':VotedUpArticleID1', (string) trim($_GET['VotedUpArticleID']), PDO::PARAM_STR);
$statement->bindValue(':VotedUpEditID1', (string) trim($_GET['VotedUpEditID']), PDO::PARAM_STR);
$statement->bindValue(':VotedDownArticleID1', (string) trim($_GET['VotedDownArticleID']), PDO::PARAM_STR);
$statement->bindValue(':VotedDownEditID1', (string) trim($_GET['VotedDownEditID']), PDO::PARAM_STR);

Answer 2

具有自己的trim功能，例如

  function nulltrim($str)
  {
      $s = trim($str);
      if ( empty($s) ) 
            return null;
      return $s;
  }

和

  $statement->bindValue(':EditID', (string) nulltrim($_GET['EditID']), PDO::PARAM_STR);

應該解決它。