PHP PDO不会在重复的键插入上引发异常 [英] PHP PDO does not throw exception on duplicate key insert

问题描述

我有一个奇怪的问题，即插入重复值时PDO不会引发异常.在这种情况下，我确实期望出现错误.

I have a strange problem with PDO not throwing an exception when a duplicate value is inserted. In this case I did expect an error.

相关代码:

try
{
  $db_conn = new PDO("mysql:host=".$config["database"]["hostname"].";charset=utf8", $config["database"]["username"], $config["database"]["password"], []);
  $db_conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
  $db_conn->exec(file_get_contents("some_file_with_data.sql");
}
catch(Exception $e)
{
  // PDOException extends RuntimeException extends Exception so exceptions should be catched here
  // however for the duplicate key entry it will not throw an exception
}

包含SQL数据的文件包含多个插入，如下所示:

The file with SQL data contains multiple inserts like this:

INSERT INTO `a` (`b`, `c`) VALUES
  (1, 1),
  (2, 2),
  (3, 2);

INSERT INTO `a` (`b`, `c`) VALUES
  (1, 1);

表a中的字段b设置为主键.当我使用phpMyAdmin在完全相同的结构中插入完全相同的数据时，出现此错误:#1062 - Duplicate entry '65533' for key 'PRIMARY'

The field b in table a is set to being the primary key. When I insert the exact same data in the exact same structure using phpMyAdmin I get this error: #1062 - Duplicate entry '65533' for key 'PRIMARY'

在这种情况下，为什么PDO不会引发错误?甚至当我将错误模式设置为异常时?

Why does PDO not throw an error in this case? Even when I set the error mode to exception?

这是用于此特定表的表结构

This is the table structure used for this specific table

CREATE TABLE IF NOT EXISTS `a` (
  `b` smallint(5) unsigned NOT NULL,
  `c` smallint(5) unsigned NOT NULL,
  PRIMARY KEY (`b`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

推荐答案

通常将其报告为具有PDO的错误:

This has often been reported as bug with PDO: https://bugs.php.net/bug.php?id=61613

仅当 FIRST 语句无效时，才会引发异常.如果第一条语句运行顺利，则不会出现任何错误-并且第一条语句是有效的:

It will only throw an exception if the FIRST Statement is invalid. If the first statement runs smooth, you won't get any error - And your first statement is valid:

INSERT INTO `a` (`b`, `c`) VALUES
  (1, 1),
  (2, 2),
  (3, 2);

作为一种解决方法-或根据您的常识正确的做法-您需要一张一行地处理行集(摘自错误报告注释):

as a workaround - or according to Your Common Sense the right way of doing it - you need to process the rowsets one-by-one (taken from the bug reports comments):

$pdo->beginTransaction();
try {
    $statement = $pdo->prepare($sql);
    $statement->execute();
    while ($statement->nextRowset()) {/* https://bugs.php.net/bug.php?id=61613 */};
    $pdo->commit();
} catch (\PDOException $e) {
    $pdo->rollBack();
    throw $e;
}

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