外键和锁 - 数据库编程

InnoDB通常不会回滚大部分错误异常，但是除了死锁，发生死锁，InnoDB会立马回滚事务，这点需要注意

[plain] 
会话A：  
mysql> begin;  
Query OK, 0 rows affected (0.00 sec)  
  
mysql> select * from t where id=1 for update;  
+----+  
| id |  
+----+  
|  1 |  
+----+  
1 row in set (0.00 sec)  
  
会话B：  
mysql> begin;  
Query OK, 0 rows affected (0.00 sec)  
  
mysql> select * from t where id=2 for update;  
+----+  
| id |  
+----+  
|  2 |  
+----+  
1 row in set (0.00 sec)  
  
会话A：  
mysql>




 select * from t where id=2 for update;  
--被阻塞  
  
会话B：  
mysql> select * from t where id=1 for update;  
ERROR 1213 (40001): Deadlock found when trying to get lock; try restarting transaction  
  
会话A：  
+----+  
| id |  
+----+  
|  2 |  
+----+  
1 row in set (16.69 sec)

外键和锁(二)