我想我已经弄明白了，对吗?：

mysql_query("START TRANSACTION");

$a1 = mysql_query("INSERT INTO rarara (l_id) VALUES('1')");
$a2 = mysql_query("INSERT INTO rarara (l_id) VALUES('2')");

if ($a1 and $a2) {
    mysql_query("COMMIT");
} else {        
    mysql_query("ROLLBACK");
}

<?php

// trans.php
function begin(){
    mysql_query("BEGIN");
}

function commit(){
    mysql_query("COMMIT");
}

function rollback(){
    mysql_query("ROLLBACK");
}

mysql_connect("localhost","Dude1", "SuperSecret") or die(mysql_error());

mysql_select_db("bedrock") or die(mysql_error());

$query = "INSERT INTO employee (ssn,name,phone) values ('123-45-6789','Matt','1-800-555-1212')";

begin(); // transaction begins

$result = mysql_query($query);

if(!$result){
    rollback(); // transaction rolls back
    echo "transaction rolled back";
    exit;
}else{
    commit(); // transaction is committed
    echo "Database transaction was successful";
}

?>

请检查您正在使用的存储引擎。如果是MyISAM，则不支持事务('COMMIT'，'ROLLBACK')，因为只有InnoDB存储引擎支持事务，MyISAM不支持事务。

我在处理事务时通常使用的思想是这样的(半伪代码):

try {
    // First of all, let's begin a transaction
    $db->beginTransaction();
    
    // A set of queries; if one fails, an exception should be thrown
    $db->query('first query');
    $db->query('second query');
    $db->query('third query');
    
    // If we arrive here, it means that no exception was thrown
    // i.e. no query has failed, and we can commit the transaction
    $db->commit();
} catch (\Throwable $e) {
    // An exception has been thrown
    // We must rollback the transaction
    $db->rollback();
    throw $e; // but the error must be handled anyway
}

Note that, with this idea, if a query fails, an Exception must be thrown:

PDO可以做到这一点，这取决于您如何配置它 看到PDO:: setAttribute 和PDO::ATTR_ERRMODE和PDO::ERRMODE_EXCEPTION 否则，使用一些其他API，您可能必须测试用于执行查询的函数的结果，并自己抛出异常。

Unfortunately, there is no magic involved. You cannot just put an instruction somewhere and have transactions done automatically: you still have to specific which group of queries must be executed in a transaction.

例如，您经常会在事务之前(开始之前)有几个查询，在事务之后(提交或回滚之后)有另外两个查询，您希望无论事务中发生了什么(或没有发生什么)，都能执行这些查询。

另一个mysqli_multi_query的过程式示例，假设$query由分号分隔的语句填充。

mysqli_begin_transaction ($link);

for (mysqli_multi_query ($link, $query);
    mysqli_more_results ($link);
    mysqli_next_result ($link) );

! mysqli_errno ($link) ?
    mysqli_commit ($link) : mysqli_rollback ($link);

我做了一个函数来获取查询向量并进行交易，也许有人会发现它有用:

function transaction ($con, $Q){
        mysqli_query($con, "START TRANSACTION");

        for ($i = 0; $i < count ($Q); $i++){
            if (!mysqli_query ($con, $Q[$i])){
                echo 'Error! Info: <' . mysqli_error ($con) . '> Query: <' . $Q[$i] . '>';
                break;
            }   
        }

        if ($i == count ($Q)){
            mysqli_query($con, "COMMIT");
            return 1;
        }
        else {
            mysqli_query($con, "ROLLBACK");
            return 0;
        }
    }