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  • mysqli::commit()

    (PHP 5, PHP 7)

    提交一个事务

    说明

    面向对象风格
    mysqli::commit(void): bool
    过程化风格
    mysqli_commit(mysqli$link): bool

    提交数据库连接的当前事务

    参数

    $link

    仅以过程化样式:由mysqli_connect()或mysqli_init()返回的链接标识。

    返回值

    成功时返回TRUE,或者在失败时返回FALSE

    范例

    Example #1 mysqli::commit() example

    面向对象风格

    <?php
    $mysqli = new mysqli("localhost", "my_user", "my_password", "world");
    /* check connection */
    if (mysqli_connect_errno()) {
        printf("Connect failed: %s\n", mysqli_connect_error());
        exit();
    }
    $mysqli->query("CREATE TABLE Language LIKE CountryLanguage");
    /* set autocommit to off */
    $mysqli->autocommit(FALSE);
    /* Insert some values */
    $mysqli->query("INSERT INTO Language VALUES ('DEU', 'Bavarian', 'F', 11.2)");
    $mysqli->query("INSERT INTO Language VALUES ('DEU', 'Swabian', 'F', 9.4)");
    /* commit transaction */
    $mysqli->commit();
    /* drop table */
    $mysqli->query("DROP TABLE Language");
    /* close connection */
    $mysqli->close();
    ?>
    

    过程化风格

    <?php
    $link = mysqli_connect("localhost", "my_user", "my_password", "test");
    /* check connection */
    if (!$link) {
        printf("Connect failed: %s\n", mysqli_connect_error());
        exit();
    }
    /* set autocommit to off */
    mysqli_autocommit($link, FALSE);
    mysqli_query($link, "CREATE TABLE Language LIKE CountryLanguage");
    /* Insert some values */
    mysqli_query($link, "INSERT INTO Language VALUES ('DEU', 'Bavarian', 'F', 11.2)");
    mysqli_query($link, "INSERT INTO Language VALUES ('DEU', 'Swabian', 'F', 9.4)");
    /* commit transaction */
    mysqli_commit($link);
    /* close connection */
    mysqli_close($link);
    ?>
    

    参见

    • mysqli_autocommit() 打开或关闭本次数据库连接的自动命令提交事务模式
    • mysqli_rollback() 回退当前事务
    I never recomend to use the ? with only one value variant like: $var = expression ? $var : other_value or $var = expression ? null : other_value ,and php suport Exception catchin so,use it :)
    here my opinion abut lorenzo's post:
     <?php
     
    //variants combined
    $mysqli->autocommit(FALSE);
    try{
     $mysqli->query("INSERT INTO myCity (id) VALUES (100)") or throw new Exception('error!');
    // or we can use
     if( !$mysqli->query("INSERT INTO myCity (id) VALUES (200)"){ 
      throw new Exception('error!'); 
     }
    }catch( Exception $e ){
     $mysqli->rollback();
    }
    $mysqli->commit();
    ?>
    
    Please note that calling mysqli::commit() will NOT automatically set mysqli::autocommit() back to 'true'.
    This means that any queries following mysqli::commit() will be rolled back when your script exits.
    This is an example to explain the powerful of the rollback and commit functions.
    Let's suppose you want to be sure that all queries have to be executed without errors before writing data on the database.
    Here's the code:
    <?php
    $all_query_ok=true; // our control variable
    //we make 4 inserts, the last one generates an error
    //if at least one query returns an error we change our control variable
    $mysqli->query("INSERT INTO myCity (id) VALUES (100)") ? null : $all_query_ok=false;
    $mysqli->query("INSERT INTO myCity (id) VALUES (200)") ? null : $all_query_ok=false;
    $mysqli->query("INSERT INTO myCity (id) VALUES (300)") ? null : $all_query_ok=false;
    $mysqli->query("INSERT INTO myCity (id) VALUES (100)") ? null : $all_query_ok=false; //duplicated PRIMARY KEY VALUE
    //now let's test our control variable
    $all_query_ok ? $mysqli->commit() : $mysqli->rollback();
    $mysqli->close();
    ?>
    hope to be helpful!
    When you have alot of transactions to make, say you are applying inserting items to the database from a loop, it will be better to use the mysqli_commit for this kind of process as it will only hit the database once.
    //Wrong way
    Example 1:
    $con = mysqli_connect("host", "username", "password", "database") or die("Could not establish connection to database");
    $users = ["chris", "james", "peter", "mark", "joe", "alice", "bob"]
    for($i=0; $i<count($users); $i++){
        $user= $users[$i];
        $query = mysqli_query($con, "INSERT INTO users (username) VALUES ('$user') ");
    } 
    //Correct Way
    Example 2
    $con = mysqli_connect("host", "username", "password", "database") or die("Could not establish connection to database");
    $users = ["chris", "james", "peter", "mark", "joe", "alice", "bob"]
    //Turn off autocommit 
    mysqli_autocommit($con, FALSE)
    //Make some transactions
    for($i=0; $i<count($users); $i++){
       $user= $users[$i];
       $query = mysqli_query($con, "INSERT INTO users (username) VALUES ('$user') ");
    } 
    //Make a one-time hit to the database 
    mysqli_commit($con)
    As with the Example 1, since we had 7 items in the list, this means that their will be a 7 times hit to our database which can really affect performance. But with the Example 2, since we already turned off autocommit this means that the transactions will be queued ontill will explicitly call mysqli_commit($con)
    This is to clarify the Flags parameters and what they mean:
    MYSQLI_TRANS_COR_AND_CHAIN: 
    Appends "AND CHAIN" to mysqli_commit or mysqli_rollback.
    MYSQLI_TRANS_COR_AND_NO_CHAIN: 
    Appends "AND NO CHAIN" to mysqli_commit or mysqli_rollback.
    MYSQLI_TRANS_COR_RELEASE: 
    Appends "RELEASE" to mysqli_commit or mysqli_rollback.
    MYSQLI_TRANS_COR_NO_RELEASE:
    Appends "NO RELEASE" to mysqli_commit or mysqli_rollback.
    To clarify those options:
    The AND CHAIN clause causes a new transaction to begin as soon as the current one ends, and the new transaction has the same isolation level as the just-terminated transaction. 
    The RELEASE clause causes the server to disconnect the current client session after terminating the current transaction.
    The compactness of Lorenzo's code is admirable.
    However, it is a good idea to also check $mysqli->affected_rows to make sure that the INSERT statement did not fail. 
    <?php
    $result_query = @mysqli_query($query, $connect);
            if (($result_query == false) &&
              (mysqli_affected_rows($connect) == 0))
             {
              // verify the query executed completely and verify that it
              // had impact on the table
              $success = false;
              // here also, the developer could choose to add a ROLLBACK
              // statement
            }
    ?>