MySQL中開啟和應用通用查詢日記的實例教程

MySQL中開啟和應用通用查詢日記的實例教程。本站提示廣大學習愛好者：（MySQL中開啟和應用通用查詢日記的實例教程）文章只能為提供參考，不一定能成為您想要的結果。以下是MySQL中開啟和應用通用查詢日記的實例教程正文

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開啟通用查詢日記
由於為了機能斟酌，普通通用查詢日記general log不會開啟。slow log可以定位一些有機能成績的sql，而general log會記載一切的SQL。

mysql5.0版本，假如要開啟slow log、general log，須要重啟，從MySQL5.1.6版開端，general query log和slow query log開端支撐寫到文件或許數據庫表兩種方法，而且日記的開啟，輸入方法的修正，都可以在Global級別靜態修正。

mysql>select version();

+————+
| version() |
+————+
| 5.1.37-log |
+————+
1 row in set (0.02 sec)

設置日記輸入方法為文件（假如設置log_output=table的話，則日記成果會記載到名為gengera_log的表中，這表的默許引擎都是CSV）：

mysql>set global log_output=file;

Query OK, 0 rows affected (0.00 sec)

設置general log的日記文件途徑：

mysql>set global general_log_file='/tmp/general.log';

Query OK, 0 rows affected (0.00 sec)

 開啟general log：

mysql>set global general_log=on;

Query OK, 0 rows affected (0.02 sec)

過一段時光後，封閉general log：

mysql>set global general_log=off;

Query OK, 0 rows affected (0.02 sec)

通用查詢日記的體系變量

log_output=[none|file|table|file,table] #通用查詢日記輸入格局

general_log=[on|off]      #能否啟用通用查詢日記

general_log_file[=filename]    #通用查詢日記地位及名字

通用查詢日記的備份

在Linux或Unix中，你可以經由過程上面的敕令從新定名文件

並創立一個新文件：

shell> mv hostname.log hostname-old.log

shell> mysqladmin flush-logs

shell> cp hostname-old.log to-backup-directory

shell> rm hostname-old.log

在Windows中，辦事器翻開日記文件時代不克不及從新定名日記文件。必需先停滯辦事器然後從新定名日記文件。然後重啟辦事器來創立新日記文件。

演示通用查詢日記的應用

a、啟用通用查詢日記

--演示情況
root@localhost[(none)]> show variables like '%version%';

+-------------------------+------------------------------+
| Variable_name  | Value  |
+-------------------------+------------------------------+
| innodb_version | 5.5.39  |
| protocol_version | 10   |
| slave_type_conversions |   |
| version  | 5.5.39-log  |
| version_comment | MySQL Community Server (GPL) |
| version_compile_machine | x86_64  |
| version_compile_os | Linux  |
+-------------------------+------------------------------+

--檢查體系變量
root@localhost[(none)]> show variables like '%general%';

+------------------+----------------------------+
| Variable_name | Value  |
+------------------+----------------------------+
| general_log | OFF  |
| general_log_file | /var/lib/mysql/suse11b.log |
+------------------+----------------------------+

--檢查以後的通用日記，顯示無日記文件
root@localhost[(none)]> system ls /var/lib/mysql/suse11b.log 

ls: cannot access /var/lib/mysql/suse11b.log: No such file or directory

--設置變量general_log以開啟通用查詢日記
root@localhost[(none)]> set @@global.general_log=1;

Query OK, 0 rows affected (0.00 sec)

--再次檢查通用日記文件已存在
root@localhost[(none)]> system ls /var/lib/mysql/suse11b.log 
/var/lib/mysql/suse11b.log
root@localhost[(none)]> select * from tempdb.tb1; --履行查詢

+------+------+
| id | val |
+------+------+
| 1 | jack |
+------+------+

--檢查通用日記文件內容
root@localhost[(none)]> system more /var/lib/mysql/suse11b.log
/usr/sbin/mysqld, Version: 5.5.39-log (MySQL Community Server (GPL)). started with:

Tcp port: 3306 Unix socket: /var/lib/mysql/mysql.sock
Time  Id Command Argument
141003 16:18:12 4 Query show variables like '%general%'
141003 16:18:55 4 Query select * from tempdb.tb1

b、更改通用查詢日記地位

root@localhost[(none)]> exit

Bye
suse11b:~ # service mysql stop
Shutting down MySQL...   done
suse11b:~ # mysqld --general_log_file=/tmp/suse11b.log --user=mysql &
[1] 47009
suse11b:~ # ps -ef|grep mysql|grep -v grep
mysql 47009 44514 1 16:22 pts/0 00:00:00 mysqld --general_log_file=/tmp/suse11b.log --user=mysql
root 47053 44514 0 16:22 pts/0 00:00:00 grep mysql
suse11b:~ # mysql

root@localhost[(none)]> system ls /tmp/suse11b.log

ls: cannot access /tmp/suse11b.log: No such file or directory

root@localhost[(none)]> show variables like '%gener%';

+------------------+------------------+
| Variable_name | Value |
+------------------+------------------+
| general_log | OFF  |
| general_log_file | /tmp/suse11b.log |
+------------------+------------------+

root@localhost[(none)]> set global general_log=on;

Query OK, 0 rows affected (0.01 sec)

--此時從體系變量看出，通用日記曾經到/tmp目次下
root@localhost[(none)]> show variables like '%gener%';

+------------------+------------------+
| Variable_name | Value |
+------------------+------------------+
| general_log | ON  |
| general_log_file | /tmp/suse11b.log |
+------------------+------------------+

--宣布查詢
root@localhost[(none)]> select count(*) from tempdb.tb1;

+----------+
| count(*) |
+----------+
| 1 |
+----------+

--檢查通用日記文件內容
root@localhost[(none)]> system more /tmp/suse11b.log

mysqld, Version: 5.5.39-log (MySQL Community Server (GPL)). started with:
Tcp port: 3306 Unix socket: /var/lib/mysql/mysql.sock
Time  Id Command Argument
141003 16:30:03 1 Query show variables like '%gener%'
141003 16:30:09 1 Query select count(*) from tempdb.tb1

c、通用查詢日記輸入方法

--可以輸入為文件，表和不輸入，即TABLE，FILE，NONE
--體系變量log_output
root@localhost[(none)]> show variables like 'log_output';

+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| log_output | FILE |
+---------------+-------+

--上面修正為輸入為表方法
root@localhost[(none)]> set global log_output='TABLE';

Query OK, 0 rows affected (0.00 sec)

root@localhost[(none)]> show variables like 'log_output';

+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| log_output | TABLE |
+---------------+-------+

--宣布查詢
root@localhost[(none)]> select * from tempdb.tb1;

+------+------+
| id | val |
+------+------+
| 1 | jack |
+------+------+

root@localhost[(none)]> system more /tmp/suse11b.log

mysqld, Version: 5.5.39-log (MySQL Community Server (GPL)). started with:
Tcp port: 3306 Unix socket: /var/lib/mysql/mysql.sock
Time  Id Command Argument
141003 16:30:03 1 Query show variables like '%gener%'
141003 16:30:09 1 Query select count(*) from tempdb.tb1
141003 16:31:00 1 Query show variables like 'log_output'
141003 17:00:48 1 Query set global log_output='TABLE' #通用查詢日記輸入到文件僅僅記載到全局變量的修正

--mysql.general_log記載了通用查詢日記的信息
root@localhost[(none)]> desc mysql.general_log;

+--------------+------------------+------+-----+-------------------+-----------------------------+
| Field | Type | Null | Key | Default  | Extra  |
+--------------+------------------+------+-----+-------------------+-----------------------------+
| event_time | timestamp | NO | | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP |
| user_host | mediumtext | NO | | NULL  |  |
| thread_id | int(11) | NO | | NULL  |  |
| server_id | int(10) unsigned | NO | | NULL  |  |
| command_type | varchar(64) | NO | | NULL  |  |
| argument | mediumtext | NO | | NULL  |  |
+--------------+------------------+------+-----+-------------------+-----------------------------+

--從通用查詢日記內外檢查通用查詢日記的內容
root@localhost[(none)]> select thread_id,command_type,argument from mysql.general_log; 

+-----------+--------------+---------------------------------------------------------------+
| thread_id | command_type | argument    |
+-----------+--------------+---------------------------------------------------------------+
| 1 | Query | show variables like 'log_output'   |
| 1 | Query | select * from tempdb.tb1   |
| 1 | Query | desc mysql.general_log   |
| 1 | Query | select thread_id,command_type,argument from mysql.general_log |
+-----------+--------------+---------------------------------------------------------------+

root@localhost[(none)]> show variables like 'log_output';

+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| log_output | TABLE |
+---------------+-------+

--應用FILE,TABLE 2者混雜輸入通用日記
root@localhost[(none)]> set global log_output='file,table';

Query OK, 0 rows affected (0.00 sec)

root@localhost[(none)]> select @@global.log_output;

+---------------------+
| @@global.log_output |
+---------------------+
| FILE,TABLE |
+---------------------+

root@localhost[(none)]> insert into tempdb.tb1 values(2,'robinson');

Query OK, 1 row affected (0.06 sec)

root@localhost[(none)]> commit;

Query OK, 0 rows affected (0.01 sec)

--驗證成果，表和文件裡邊存在通用的日記記載
root@localhost[(none)]> system tail /tmp/suse11b.log|grep robinson

141003 17:41:54 2 Query insert into tempdb.tb1 values(2,'robinson')

root@localhost[(none)]> select thread_id,command_type,argument from mysql.general_log
 -> where argument like '%robinson%';

+-----------+--------------+------------------------------------------------------------------------+
| thread_id | command_type | argument     |
+-----------+--------------+------------------------------------------------------------------------+
| 2 | Query | insert into tempdb.tb1 values(2,'robinson')  |
| 2 | Query | select thread_id,command_type,argument from mysql.general_log |
|  |  | where argument like ''robinson''   | 
+-----------+--------------+------------------------------------------------------------------------+

d、封閉通用查詢日記

--可以經由過程設置體系變量general_log來封閉通用查詢日記，此光陰志輸入設置為FILE,TABLE

root@localhost[(none)]> show variables like 'log_output';

+---------------+------------+
| Variable_name | Value |
+---------------+------------+
| log_output | FILE,TABLE |
+---------------+------------+

root@localhost[(none)]> set global general_log=off;

Query OK, 0 rows affected (0.01 sec)

root@localhost[(none)]> show variables like '%gener%';

+------------------+------------------+
| Variable_name | Value |
+------------------+------------------+
| general_log | OFF  |
| general_log_file | /tmp/suse11b.log |
+------------------+------------------+

root@localhost[(none)]> delete from tempdb.tb1 where id=2;

Query OK, 1 row affected (0.12 sec)

root@localhost[(none)]> commit;

Query OK, 0 rows affected (0.00 sec)

root@localhost[(none)]> system tail -n 1 /tmp/suse11b.log

141003 17:45:13 2 Query set global general_log=off

root@localhost[(none)]> select thread_id,command_type,argument from mysql.general_log
 -> where argument like '%delete%';

Empty set (0.00 sec)
--從下面的演示可知，雖然我們設置了log_output為FILE,TABLE，但general_log為OFF，通用日記無任何記載發生

root@localhost[(none)]> set global log_output=none;

Query OK, 0 rows affected (0.00 sec)

root@localhost[(none)]> set global general_log=1;

Query OK, 0 rows affected (0.00 sec)

root@localhost[(none)]> truncate table tempdb.tb1;

Query OK, 0 rows affected (0.01 sec)

root@localhost[(none)]> system tail -n 1 /tmp/suse11b.log

Time  Id Command Argument

--經由過程下面的演示，在log_output=none,general_log=on的清下下無任何通用日記輸入。