java-具有两个sql插入的事务

我有两个sql插入(例如表A和B中的示例),它们在事务中,因为我希望数据库保持一致,也就是说,A中的元组必须在B中具有引用.

在第二个插入中,我需要第一个插入的ID,但是直到对事务进行提交后,我才能获得该ID.
所以我被卡住了.我不想从事务中取出第一个插入,可能会发生第一个插入正常但第二个插入没问题的情况,这使我在数据库中处于不一致状态.

在这种情况下最佳做法是什么？

编辑：这是代码：

TransactionStatus txStatus = transactionManager.getTransaction(txDefinition);
try{
    Integer aId = insertIntoA();
    insertIntoB(aId);
}catch(){
    transactionManager.rollback(txStatus);
    throw new CustomException(); 
}
transactionManager.commit(txStatus);

我要指出的是,在提交事务之前,我不会获得aId,因此将null插入B中.

最佳答案

在MySQL上,您可以在insertIntoA中执行以下操作：

SELECT LAST_INSERT_ID()

…在您用于插入的同一连接上,假设它是您要查找的标识列值.

编辑：如果您正在这样做并且不起作用(根据您的评论),我将查看中间层以查看正在发生的情况. MySQL可以：

mysql> create table A (id int(11) not null auto_increment,descr varchar(64),primary key (id));
Query OK,0 rows affected (0.13 sec)

mysql> create table B (fk int(11) not null,descr varchar(64));
Query OK,0 rows affected (0.06 sec)

mysql> start transaction;
Query OK,0 rows affected (0.00 sec)

mysql> insert into A (descr) values ('Testing 1 2 3');
Query OK,1 row affected (0.00 sec)

mysql> select last_insert_id();
+------------------+
| last_insert_id() |
+------------------+
|                1 |
+------------------+
1 row in set (0.03 sec)

mysql> insert into B (fk,descr) values (1,'Test complete');
Query OK,1 row affected (0.00 sec)

mysql> commit;
Query OK,0 rows affected (0.03 sec)

mysql> select * from A;
+----+---------------+
| id | descr         |
+----+---------------+
|  1 | Testing 1 2 3 |
+----+---------------+
1 row in set (0.02 sec)

mysql> select * from B;
+----+---------------+
| fk | descr         |
+----+---------------+
|  1 | Test complete |
+----+---------------+
1 row in set (0.00 sec)

mysql> start transaction;
Query OK,0 rows affected (0.00 sec)

mysql> insert into A (descr) values ('Second test');
Query OK,1 row affected (0.01 sec)

mysql> select last_insert_id();
+------------------+
| last_insert_id() |
+------------------+
|                2 |
+------------------+
1 row in set (0.00 sec)

mysql> insert into B (fk,descr) values (2,'Second test complete');
Query OK,0 rows affected (0.08 sec)

mysql> select * from A;
+----+---------------+
| id | descr         |
+----+---------------+
|  1 | Testing 1 2 3 |
|  2 | Second test   |
+----+---------------+
2 rows in set (0.02 sec)

mysql> select * from B;
+----+----------------------+
| fk | descr                |
+----+----------------------+
|  1 | Test complete        |
|  2 | Second test complete |
+----+----------------------+
2 rows in set (0.00 sec)

mysql> start transaction;
Query OK,0 rows affected (0.00 sec)

mysql> insert into A (descr) values ('We''ll roll this one back.');
Query OK,1 row affected (0.00 sec)

mysql> select last_insert_id();
+------------------+
| last_insert_id() |
+------------------+
|                3 |
+------------------+
1 row in set (0.00 sec)

mysql> insert into B (fk,descr) values (3,'Won''t see this one.');
Query OK,1 row affected (0.00 sec)

mysql> select * from B;
+----+----------------------+
| fk | descr                |
+----+----------------------+
|  1 | Test complete        |
|  2 | Second test complete |
|  3 | Won't see this one.  |
+----+----------------------+
3 rows in set (0.00 sec)

mysql> rollback;
Query OK,0 rows affected (0.03 sec)

mysql> select * from A;
+----+---------------+
| id | descr         |
+----+---------------+
|  1 | Testing 1 2 3 |
|  2 | Second test   |
+----+---------------+
2 rows in set (0.00 sec)

mysql> select * from B;
+----+----------------------+
| fk | descr                |
+----+----------------------+
|  1 | Test complete        |
|  2 | Second test complete |
+----+----------------------+
2 rows in set (0.00 sec)