MySQL中允许嵌套事务吗？

Question

MySQL是否允许使用嵌套事务？

Answer 1

InnoDB支持SAVEPOINTS。

你可以做到以下几点：

CREATE TABLE t_test (id INT NOT NULL PRIMARY KEY) ENGINE=InnoDB; 

START TRANSACTION; 

INSERT 
INTO t_test 
VALUES (1); 

SELECT * 
FROM t_test; 

id 
--- 
    1 

SAVEPOINT tran2; 

INSERT 
INTO t_test 
VALUES (2); 

SELECT * 
FROM t_test; 

id 
--- 
    1 
    2 

ROLLBACK TO tran2; 

SELECT * 
FROM t_test; 

id 
--- 
    1 

ROLLBACK; 

SELECT * 
FROM t_test; 

id 
--- 

Answer 2

如果您使用PHP，那么你可以是有趣的https://github.com/Enelar/phpsql 它支持MySQL和pgsql的，并可延伸到其它连接器。

function TransferMoney() 
{ // Nested transaction code could not even know that he nested 
    $trans3 = db::Begin(); 
    if (!db::Query("--Withdraw money from user", [$uid, $amount], true)) 
    return $trans3->Rollback(); 
    db::Query("--Deposit money to system"); 
    return $trans3->Commit(); 
} 

$trans = db::Begin(); 
db::Query("--Give item to user inventory"); 
    $trans2 = $trans->Begin(); 
    $trans2->Query("--Try some actions and then decide to rollback"); 
    $trans2->Rollback(); 
// Commit or rollback depending on money transfer result 
return $trans->Finish(TransferMoney()); 

Answer 3

从

MySQL文档：

事务不能被嵌套。当您发出START TRANSACTION语句或其同义词之一时，这是对任何当前事务执行的隐式提交的结果。 https://dev.mysql.com/doc/refman/5.7/en/implicit-commit.html