日韩性视频-久久久蜜桃-www中文字幕-在线中文字幕av-亚洲欧美一区二区三区四区-撸久久-香蕉视频一区-久久无码精品丰满人妻-国产高潮av-激情福利社-日韩av网址大全-国产精品久久999-日本五十路在线-性欧美在线-久久99精品波多结衣一区-男女午夜免费视频-黑人极品ⅴideos精品欧美棵-人人妻人人澡人人爽精品欧美一区-日韩一区在线看-欧美a级在线免费观看

歡迎訪問 生活随笔!

生活随笔

當前位置: 首頁 > 编程资源 > 编程问答 >内容正文

编程问答

间隙锁例子

發布時間:2025/6/15 编程问答 19 豆豆
生活随笔 收集整理的這篇文章主要介紹了 间隙锁例子 小編覺得挺不錯的,現在分享給大家,幫大家做個參考.

?

session A:  session B:   
 ??????? 
mysql> show variables like '%iso%';mysql> show variables like '%iso%'; 
+---------------+-----------------++---------------+-----------------+ 
| Variable_name | Value???????????|| Variable_name | Value???????????| 
+---------------+-----------------++---------------+-----------------+ 
| tx_isolation??| REPEATABLE-READ || tx_isolation??| REPEATABLE-READ | 
+---------------+-----------------++---------------+-----------------+ 
1 row in set (0.00 sec)?1 row in set (0.00 sec)? 
 ??????? 
mysql> begin;??mysql> begin;?? 
Query OK, 0 rows affected (0.00 sec)Query OK, 0 rows affected (0.00 sec)
 ??????? 
mysql> select * from user;?mysql> select * from user;? 
+----+--------+??+----+--------+?? 
| id | name???|??| id | name???|?? 
+----+--------+??+----+--------+?? 
|??1 | ligang |??|??1 | ligang |?? 
|??2 | lvbu???|??|??2 | lvbu???|?? 
|??3 | zhaoyu |??|??3 | zhaoyu |?? 
+----+--------+??+----+--------+?? 
3 rows in set (0.00 sec)?3 rows in set (0.00 sec)? 
 ??????? 
mysql> update user set name='ddd' where id=4;??? 
Query OK, 0 rows affected (0.00 sec)???? 
Rows matched: 0??Changed: 0??Warnings: 0??? 
(把存在ddd之外的記錄全部加X鎖)???? 
 ???mysql> insert into user values(4,'ddd');
 ???ERROR 1205 (HY000): Lock wait timeout exceeded;?
 ???try restarting transaction? 
 ??????? 
mysql> commit;?????? 
Query OK, 0 rows affected (0.00 sec)???? 
 ??????? 
 ???mysql> insert into user values(4,'ddd');
 ???Query OK, 1 row affected (0.00 sec) 
 ??????? 
 ???mysql> select * from user;? 
 ???+----+--------+?? 
 ???| id | name???|?? 
 ???+----+--------+?? 
 ???|??4 | ddd????|?? 
 ???|??1 | ligang |?? 
 ???|??2 | lvbu???|?? 
 ???|??3 | zhaoyu |?? 
 ???+----+--------+?? 
 ???4 rows in set (0.01 sec)? 
 ??????? 
mysql> begin;?????? 
Query OK, 0 rows affected (0.00 sec)???? 
 ??????? 
mysql> select * from user;????? 
+----+--------+?????? 
| id | name???|?????? 
+----+--------+?????? 
|??1 | ligang |?????? 
|??2 | lvbu???|?????? 
|??3 | zhaoyu |?????? 
+----+--------+?????? 
3 rows in set (0.00 sec)????? 
 ??????? 
 ???mysql> commit;?? 
 ???Query OK, 0 rows affected (0.00 sec)
 ??????? 
mysql> select * from user;????? 
+----+--------+?????? 
| id | name???|?????? 
+----+--------+?????? 
|??1 | ligang |?????? 
|??2 | lvbu???|?????? 
|??3 | zhaoyu |?????? 
+----+--------+?????? 
3 rows in set (0.00 sec)????? 
 ??????? 
mysql> commit;?????? 
Query OK, 0 rows affected (0.00 sec)???? 
 ??????? 
mysql> select * from user;????? 
+----+--------+?????? 
| id | name???|?????? 
+----+--------+?????? 
|??4 | ddd????|?????? 
|??1 | ligang |?????? 
|??2 | lvbu???|?????? 
|??3 | zhaoyu |?????? 
+----+--------+?????? 
4 rows in set (0.00 sec)      

?

?

?

session A:  session B:   
 ??????? 
mysql> show variables like '%iso%';mysql> show variables like '%iso%'; 
+---------------+----------------++---------------+----------------+ 
| Variable_name | Value??????????|| Variable_name | Value??????????| 
+---------------+----------------++---------------+----------------+ 
| tx_isolation??| READ-COMMITTED || tx_isolation??| READ-COMMITTED | 
+---------------+----------------++---------------+----------------+ 
1 row in set (0.00 sec)?1 row in set (0.00 sec)? 
 ??????? 
mysql> begin;??mysql> begin;?? 
Query OK, 0 rows affected (0.00 sec)Query OK, 0 rows affected (0.00 sec)
 ??????? 
mysql> select * from user;?mysql> select * from user;? 
+----+--------+??+----+--------+?? 
| id | name???|??| id | name???|?? 
+----+--------+??+----+--------+?? 
|??4 | ddd????|??|??4 | ddd????|?? 
|??1 | ligang |??|??1 | ligang |?? 
|??2 | lvbu???|??|??2 | lvbu???|?? 
|??3 | zhaoyu |??|??3 | zhaoyu |?? 
+----+--------+??+----+--------+?? 
4 rows in set (0.02 sec)?4 rows in set (0.02 sec)? 
 ??????? 
mysql> update user set name='cvvt' where id=5;?? 
Query OK, 0 rows affected (0.01 sec)???? 
Rows matched: 0??Changed: 0??Warnings: 0??? 
 ??????? 
 ???mysql> insert into user values (5,'cvvt');
 ???Query OK, 1 row affected (0.00 sec) 
 ??????? 
 ???mysql> select * from user;? 
 ???+----+--------+?? 
 ???| id | name???|?? 
 ???+----+--------+?? 
 ???|??5 | cvvt???|?? 
 ???|??4 | ddd????|?? 
 ???|??1 | ligang |?? 
 ???|??2 | lvbu???|?? 
 ???|??3 | zhaoyu |?? 
 ???+----+--------+?? 
 ???5 rows in set (0.00 sec)? 
 ??????? 
mysql>??select * from user;???? 
+----+--------+?????? 
| id | name???|?????? 
+----+--------+?????? 
|??4 | ddd????|?????? 
|??1 | ligang |?????? 
|??2 | lvbu???|?????? 
|??3 | zhaoyu |?????? 
+----+--------+?????? 
4 rows in set (0.00 sec)????? 
 ??????? 
 ???mysql> commit;?? 
 ???Query OK, 0 rows affected (0.00 sec)
 ??????? 
mysql>??select * from user;???? 
+----+--------+?????? 
| id | name???|?????? 
+----+--------+?????? 
|??5 | cvvt???|?????? 
|??4 | ddd????|?????? 
|??1 | ligang |?????? 
|??2 | lvbu???|?????? 
|??3 | zhaoyu |?????? 
+----+--------+?????? 
5 rows in set (0.00 sec)      
本文轉自 liang3391 51CTO博客,原文鏈接:http://blog.51cto.com/liang3391/827971

總結

以上是生活随笔為你收集整理的间隙锁例子的全部內容,希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯,歡迎將生活随笔推薦給好友。