mysql - PDO 使用 bindParam 返回 MySQL 错误

Question

嘿伙计们，我在这里运行这个小功能

function getBeaches() {

$request=Slim::getInstance()->request();

$args=filter_var_array(func_get_args(),FILTER_SANITIZE_STRING); 
$sql="SELECT * FROM beaches WHERE state=:state AND city=:city"; 

    //  var_export($args); die();
    //  array ( 0 => 'wa', 1 => 'seattle', )

try {
    $db         = getConnection();
    $stmt       = $db->prepare($sql);


        $stmt->bindValue('state',   $args[0], PDO::PARAM_STR); //should bind wa 
        $stmt->bindValue('city',    $args[1], PDO::PARAM_STR); //should bind seattle
        $stmt->execute();

    $stmt       = $db->query($sql);
    $beaches    = $stmt->fetchObject();
    $db         = null;

    echo '{"map": ' . stripslashes(json_encode($beaches)) . '}';
} catch(PDOException $e) {
    echo '{"error":{"text":'. $e->getMessage() .'}}';
}

    /* {"error":{"text":SQLSTATE[42000]: Syntax error or access violation: 
     * 1064 You have an error in your SQL syntax; check the manual that  
     * corresponds to your MySQL server version for the right syntax to use 
     * near ':state AND city=:city' at line 1}}
     */

}

并且收到我在底部评论的错误，尝试像这样运行

mysql$ SELECT * FROM beach WHERE state='wa' AND city='seattle';

这可能会敲响一些警钟吗？

Answer 1

您的参数名称之前需要使用分号: (不是 100% true，请参阅编辑)

$stmt->bindValue(':state',   $args[0], PDO::PARAM_STR); //should bind wa 
$stmt->bindValue(':city',    $args[1], PDO::PARAM_STR); //should bind seattle

来自 PDOStatement::bindValue() 上的 PHP 文档:

Parameter identifier. For a prepared statement using named placeholders, this will be a parameter name of the form :name. For a prepared statement using question mark placeholders, this will be the 1-indexed position of the parameter.

编辑正如@jeroen指出的问题(与您的pastebin中的问题相同)，您在从中获取数据之前覆盖了$stmt变量。在您的代码中，问题出在第 17 行左右:

$stmt->execute();  // $stmt now has query results (from the query with parameters bounded)

$stmt       = $db->query($sql); // You redo the query. Now $stmt has no query results and no parameters are bound
$beaches    = $stmt->fetchObject(); // Statement assumes you want to execute query and does so but not parameters are bound

您可以通过将上面的行更改为来解决此问题:

$stmt->execute();
$beaches = $stmt->fetchObject();