PHP PDO：使用参数两次时参数号无效？

2022-02-26 00:00:00 position parameters php mysql pdo

我有一个问题，当我使用位置参数两次时，我不能在PDO(PHP/MySQL)中使用SQL语句：

SELECT `ID` FROM `_LOGIN_` WHERE `LoginName` = :loginName AND `sha512`= SHA2(CONCAT(:pw, (SELECT `salt` FROM `_LOGIN_` WHERE `LoginName` = :loginName)), 512)

如您所见，我使用了两次"：loginName"。因此出现以下错误消息：

PHP Fatal error:  Uncaught PDOException: SQLSTATE[HY093]: Invalid parameter number in ...

我是否遗漏了什么，或者是否有其他方法准备语句，以便我可以多次使用参数？

下面是要复制的完整代码：

<!DOCTYPE html>
<html>
  <head>
    <title>pdo</title>   

    <meta   charset = "utf-8" />
  </head>

  <body>
      <h1>PDO Prepare</h1>

      <!--
      DB:

DROP   DATABASE IF EXISTS `pdoTestDB`;
CREATE DATABASE           `pdoTestDB`;
ALTER  DATABASE           `pdoTestDB` DEFAULT CHARACTER SET 'utf8' DEFAULT COLLATE 'utf8_general_ci';

CREATE TABLE `_LOGIN_` (
 `ID`           int(11)      NOT NULL
,`LoginName`    TEXT         NOT NULL 
,`SALT`         varchar(  6) NOT NULL 
,`sha512`       varchar(128) NOT NULL 
,`registerTS`   TIMESTAMP    NOT NULL DEFAULT CURRENT_TIMESTAMP 
,`lastLoginTS`  TIMESTAMP    NOT NULL DEFAULT CURRENT_TIMESTAMP 
, PRIMARY KEY (`ID`)
) ;

SELECT @SALT:=SUBSTRING(MD5(RAND()) FROM 1 FOR 6);

INSERT INTO `_LOGIN_`
(`ID`, `LoginName`, `salt`, `sha512`                                     , `registerTS`         ) VALUES
(   1, 'muma'      , @SALT, SHA2(CONCAT('123', @SALT), 512), '2018-06-04'         );
      -->

<?php
$PDOcharset = 'utf8mb4';
// set data source name:
$dsn = "mysql:host=localhost;dbname=pdoTestDB;charset=$PDOcharset";
$opt = [
    PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
    PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
    PDO::ATTR_EMULATE_PREPARES   => false,
];
$pdo = new PDO($dsn, "santisPHP", "123", $opt);

// the sql
$sql = "SELECT `ID` FROM `_LOGIN_` WHERE `LoginName` = :loginName AND `sha512`= SHA2(CONCAT(:pw, (SELECT `salt` FROM `_LOGIN_` WHERE `LoginName` = :loginName)), 512)";

$stmt = $pdo->prepare($sql);

$paramsAssoc = ['loginName' => "muma", 'pw' => "123"];
        //echo $paramsAssoc;
var_dump($stmt);
var_dump($paramsAssoc);

$result = $stmt->execute($paramsAssoc);

$fetched = $stmt->fetch();

echo "stmt: ";
var_dump($stmt);
echo "<br />";

echo "result: ";
var_dump($result);
echo "<br />";

echo "fetched: ";
var_dump($fetched);
echo "<br />";
?>

  </body>

</html>

解决方案

或者，您可以将设置更改为PDO::ATTR_EMULATE_PREPARES => true。这将允许您通过在PDO本身(而不是在MySQL服务器上)准备语句来多次绑定相同的命名参数。

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