在MySQL中如何給普通用戶授予查看所有用戶線程/連接的許可權，當然,預設情況下show processlist是可以查看當前用戶的線程/連接的。 mysql> grant process on MyDB.* to test; ERROR 1221 (HY000): Incorrect usage o... ...
在MySQL中如何給普通用戶授予查看所有用戶線程/連接的許可權，當然,預設情況下show processlist是可以查看當前用戶的線程/連接的。
mysql> grant process on MyDB.* to test;
ERROR 1221 (HY000): Incorrect usage of DB GRANT and GLOBAL PRIVILEGES
第一次授予這樣的許可權，錯誤原因是process許可權是一個全局許可權，不可以指定在某一個庫上（個人測試庫為MyDB），所以，把授權語句更改為如下即可：
mysql> grant process on *.* to test;
Query OK, 0 rows affected (0.01 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)
如果不給擁有授予PROESS許可權 ，show processlist命令只能看到當前用戶的線程，而授予了PROCESS許可權後，使用show processlist就能看到所有用戶的線程。官方文檔的介紹如下：
SHOW PROCESSLIST shows you which threads are running. You can also get this information from the INFORMATION_SCHEMA PROCESSLIST table or the mysqladmin processlist command. If you have the PROCESS privilege, you can see all threads. Otherwise, you can see only your own threads (that is, threads associated with the MySQL account that you are using). If you do not use the FULL keyword, only the first 100 characters of each statement are shown in the Info field.
我們先創建下麵賬號test2,然後測試如下：
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> grant select,insert,update,delete on MyDB.* to test2@'%' identified by 'test2';
Query OK, 0 rows affected (0.00 sec)mysql> flush privileges;Query OK, 0 rows affected (0.01 sec)
mysql> select user();
+-----------------+
| user() |+-----------------+
| test2@localhost |
+-----------------+
1 row in set (0.00 sec)
mysql> show processlist;
+----+-------+-----------+------+---------+------+-------+------------------+
| Id | User | Host | db | Command | Time | State | Info |
+----+-------+-----------+------+---------+------+-------+------------------+
| 25 | test2 | localhost | NULL | Query | 0 | init | show processlist |+----+-------+-----------+------+---------+------+-------+------------------+
1 row in set (0.00 sec)
mysql> show full processlist;+----+-------+-----------+------+---------+------+-------+-----------------------+
| Id | User | Host | db | Command | Time | State | Info |
+----+-------+-----------+------+---------+------+-------+-----------------------+
| 25 | test2 | localhost | NULL | Query | 0 | init | show full processlist |
+----+-------+-----------+------+---------+------+-------+-----------------------+
1 row in set (0.01 sec)
mysql>
![clip_image001[4]](http://images2017.cnblogs.com/blog/73542/201708/73542-20170824105645277-17847368.png "clip_image001[4]")
然後我們給用戶test2授予process許可權, 如下所示,再測試show processlist 就能看到所有用戶的線程/連接信息（如果是之前已經建立連接的會話，必須退出重新登錄，否則依然只能看到當前用戶的線程。）
mysql> grant process on *.* to test2;
Query OK, 0 rows affected (0.00 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
mysql> show processlist;
+----+-------+-----------+------+---------+------+-------+------------------+
| Id | User | Host | db | Command | Time | State | Info |
+----+-------+-----------+------+---------+------+-------+------------------+
| 19 | root | localhost | NULL | Sleep | 16 | | NULL |
| 22 | test | localhost | MyDB | Sleep | 738 | | NULL || 24 | test | localhost | NULL | Sleep | 692 | | NULL |
| 25 | test2 | localhost | NULL | Sleep | 531 | | NULL |
| 27 | test2 | localhost | NULL | Query | 0 | init | show processlist |+----+-------+-----------+------+---------+------+-------+------------------+
5 rows in set (0.00 sec)
mysql>
The PROCESS privilege pertains to display of information about the threads executing within the server (that is, information about the statements being executed by sessions). The privilege enables use of SHOW PROCESSLIST or mysqladmin processlist to see threads belonging to other accounts; you can always see your own threads. The PROCESS privilege also enables use of SHOW ENGINE.
如上官方文檔所說，如果給用戶授予了PROCESS許可權， 那麼用戶就擁有了使用SHOW ENGINES命令的許可權，如下所示：
mysql> select user();
+----------------+
| user() |+----------------+
| test@localhost |
+----------------+
1 row in set (0.00 sec)
mysql> show engines;
+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
| Engine | Support | Comment | Transactions | XA | Savepoints |
+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
| MRG_MYISAM | YES | Collection of identical MyISAM tables | NO | NO | NO |
| CSV | YES | CSV storage engine | NO | NO | NO |
| MyISAM | YES | MyISAM storage engine | NO | NO | NO |
| BLACKHOLE | YES | /dev/null storage engine (anything you write to it disappears) | NO | NO | NO |
| MEMORY | YES | Hash based, stored in memory, useful for temporary tables | NO | NO | NO |
