PHP 在循环中准备语句和事务 [英] PHP prepared statements and transactions in a loop

问题描述

循环代码中的经典事务:

The classic transactions in a loop code:

$mysqli->query("START TRANSACTION");
foreach ($pdata as $key => $value) {
    $sql    = "INSERT INTO temp (`fund_id`) VALUES (" . $value . ")";
    $result = $mysqli->query($sql);
}
$mysqli->query("COMMIT");

然后我们更改为准备好的语句:

Then we change to prepared statements:

$mysqli->autocommit(FALSE);
foreach ($pdata as $key => $value) {
    $sql  = "INSERT INTO temp (`fund_id`) VALUES (?)";
    $stmt = $mysqli->prepare($sql);
    $stmt->bind_param('i', $value);
    $stmt->execute();
}
$mysqli->commit();

问题:

1) 这两个代码是否相同?我是否在带有准备好的语句的第二个代码中遗漏了什么?

1) Are these two codes identical? Am I missing something in the second code with prepared statements?

2) $mysqli->commit() 和 $mysqli->query("COMMIT") 一样吗?

2) Is $mysqli->commit() the same as $mysqli->query("COMMIT")?

3) 我是否需要为准备好的语句块添加 $mysqli->query("START TRANSACTION"); 或者当我们设置 autocommit(FALSE) 时事务将自动启动)?

3) Do I need to add $mysqli->query("START TRANSACTION"); for the prepared statements block or the transaction will automatically start when we set autocommit(FALSE)?

推荐答案

可以通过将 prepare 和 bind_param 语句拉出循环来优化循环.

Your loop can be optimized by pulling the prepare and bind_param statements out of the loop.

$value = null;
$mysqli->autocommit(FALSE);
$sql  = "INSERT INTO temp (`fund_id`) VALUES (?)";
$stmt = $mysqli->prepare($sql);
$stmt->bind_param('i', $value);
foreach ($pdata as $value) {
    $stmt->execute();
}
$mysqli->commit();

您已使用 autocommit(FALSE) 行关闭自动提交，因此不需要使用 START TRANSACTION 语句.

You have turned off autocommit with your autocommit(FALSE) line and therefore don't need to use the START TRANSACTION statement.

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