PHP + MySQL事务的例子

我真的没有find正在使用MySQL交易的PHP文件的正常例子。 你能告诉我一个简单的例子吗?

还有一个问题。 我已经做了很多编程,并没有使用交易。 我可以把一个PHP函数或什么东西在header.php ,如果一个mysql_query失败,那么其他人也失败了?


我想我已经明白了,是不是?

 mysql_query("SET AUTOCOMMIT=0"); 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"); } 

我通常在处理事务时使用的想法如下所示(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 // ie no query has failed, and we can commit the transaction $db->commit(); } catch (Exception $e) { // An exception has been thrown // We must rollback the transaction $db->rollback(); } 

请注意,有了这个想法,如果查询失败,则必须抛出一个exception:

  • PDO可以做到这一点,这取决于你如何configuration它
    • 请参阅PDO::setAttribute
    • PDO::ATTR_ERRMODEPDO::ERRMODE_EXCEPTION
  • 否则,在使用其他API的情况下,您可能需要testing用于执行查询的函数的结果,并自己抛出exception。

不幸的是,没有涉及的魔法。 您不能只在某个地方放置指令,并自动完成交易:您仍然必须指定在事务中必须执行哪组查询。

例如,在事务之前(在begin之前)以及在事务之后的另外几个查询(在commitrollback ,经常会有几个查询,并且不pipe发生了什么事情(或不)在交易中。

我想我已经明白了,是不是?

 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"; } ?> 

由于这是“php mysql transaction”的谷歌第一个结果,我想我会添加一个答案,明确演示如何做到这一点与mysqli(作为原作者想要的例子)。 下面是PHP / mysqli事务的一个简单例子:

 // let's pretend that a user wants to create a new "group". we will do so // while at the same time creating a "membership" for the group which // consists solely of the user themselves (at first). accordingly, the group // and membership records should be created together, or not at all. // this sounds like a job for: TRANSACTIONS! (*cue music*) $group_name = "The Thursday Thumpers"; $member_name = "EleventyOne"; $conn = new mysqli($db_host,$db_user,$db_passwd,$db_name); // error-check this // note: this is meant for InnoDB tables. won't work with MyISAM tables. try { $conn->autocommit(FALSE); // ie, start transaction // assume that the TABLE groups has an auto_increment id field $query = "INSERT INTO groups (name) "; $query .= "VALUES ('$group_name')"; $result = $conn->query($query); if ( !$result ) { $result->free(); throw new Exception($conn->error); } $group_id = $conn->insert_id; // last auto_inc id from *this* connection $query = "INSERT INTO group_membership (group_id,name) "; $query .= "VALUES ('$group_id','$member_name')"; $result = $conn->query($query); if ( !$result ) { $result->free(); throw new Exception($conn->error); } // our SQL queries have been successful. commit them // and go back to non-transaction mode. $conn->commit(); $conn->autocommit(TRUE); // ie, end transaction } catch ( Exception $e ) { // before rolling back the transaction, you'd want // to make sure that the exception was db-related $conn->rollback(); $conn->autocommit(TRUE); // ie, end transaction } 

另外,请记住,PHP 5.5有一个新的方法mysqli :: begin_transaction 。 不过,这个还没有被PHP团队logging下来,而且我仍然被困在PHP 5.3中,所以我不能评论它。

请检查您正在使用哪个存储引擎。 如果是MyISAM,则不支持Transaction('COMMIT','ROLLBACK')因为只有InnoDB存储引擎,而不是MyISAM,支持事务。

我做了一个函数来获得一个查询的vector,做一个事务,也许有人会发现它是有用的:

 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; } } 

我有这个,但不知道这是否正确。 也可以试试这个。

 mysql_query("START TRANSACTION"); $flag = true; $query = "INSERT INTO testing (myid) VALUES ('test')"; $query2 = "INSERT INTO testing2 (myid2) VALUES ('test2')"; $result = mysql_query($query) or trigger_error(mysql_error(), E_USER_ERROR); if (!$result) { $flag = false; } $result = mysql_query($query2) or trigger_error(mysql_error(), E_USER_ERROR); if (!$result) { $flag = false; } if ($flag) { mysql_query("COMMIT"); } else { mysql_query("ROLLBACK"); } 

想法从这里: http : //www.phpknowhow.com/mysql/transactions/

使用PDO连接时:

 $pdo = new PDO('mysql:host=localhost;dbname=mydb;charset=utf8', $user, $pass, [ PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION, // this is important ]); 

我经常使用下面的代码进行事务pipe理:

 function transaction(Closure $callback) { global $pdo; // let's assume our PDO connection is in a global var // start the transaction outside of the try block, because // you don't want to rollback a transaction that failed to start $pdo->beginTransaction(); try { $callback(); $pdo->commit(); } catch (Exception $e) // it's better to replace this with Throwable on PHP 7+ { $pdo->rollBack(); throw $e; // we still have to complain about the exception } } 

用法示例:

 transaction(function() { global $pdo; $pdo->query('first query'); $pdo->query('second query'); $pdo->query('third query'); }); 

这样,整个项目中的交易pipe理代码就不会重复。 这是一件好事,因为从这个线程中的其他PDO相关的回答来看,很容易犯这个错误。 最常见的是忘记重新抛出exception并在try块内启动事务。

使用mysqli_multi_query另一个过程样式示例假定$query填充了以分号分隔的语句。

 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);