我们有时候需要查看mysql的执行历史,比如我们做sql优化的时候,起码要知道执行的sql是什么,框架一般会帮我们拼装sql,所以在程序中不一定能够打印出sql,这个时候就需要mysql的general
log了。
<code class="hljs lasso">show VARIABLES like '%general_log%'; set GLOBAL general_log = off;// on-打开; off-关闭 general_log ON general_log_file /var/log/mysql/query.log </code>
使用mysql general log
<code class="hljs lasso"><code class="hljs sql">tail -f /path/to/log/query.log | grep yourtable 13518 Prepare SELECT count(*) AS `count` FROM `babysitter_tips` WHERE (tip_type = '1') AND (is_enable = 1) AND (is_tip = 2) 13518 Query DESCRIBE `babysitter_tips` 13518 Close stmt 13518 Prepare SELECT `babysitter_tips`.* FROM `babysitter_tips` WHERE (tip_type = '1') AND (is_enable = 1) AND (is_tip = 2) ORDER BY `created_time` desc LIMIT 5 13518 Reset stmt 13518 Close stmt 13518 Prepare SELECT count(*) AS `count` FROM `babysitter_tips` WHERE (tip_type = '1') AND (is_enable = 1) AND (is_tip = 2) AND (tip_id > 15440) 13518 Close stmt 13518 Prepare SELECT count(*) AS `count` FROM `babysitter_tips` WHERE (tip_type = '3') AND (is_enable = 1) AND (is_tip = 2) 13518 Query DESCRIBE `babysitter_tips` 13518 Close stmt 13518 Prepare SELECT `babysitter_tips`.* FROM `babysitter_tips` WHERE (tip_type = '3') AND (is_enable = 1) AND (is_tip = 2) ORDER BY `created_time` desc LIMIT 5 13518 Reset stmt 13518 Close stmt 13518 Prepare SELECT count(*) AS `count` FROM `babysitter_tips` WHERE (tip_type = '3') AND (is_enable = 1) AND (is_tip = 2) AND (tip_id > '') 13518 Close stmt 13518 Prepare SELECT count(*) AS `count` FROM `babysitter_tips` WHERE (tip_type = '2') AND (is_enable = 1) AND (is_tip = 2) 13518 Query DESCRIBE `babysitter_tips` 13518 Close stmt 13518 Prepare SELECT `babysitter_tips`.* FROM `babysitter_tips` WHERE (tip_type = '2') AND (is_enable = 1) AND (is_tip = 2) ORDER BY `created_time` desc LIMIT 5 13518 Reset stmt 13518 Close stmt</code></code>
<code class="hljs sql">清理mysql general log
<code class="hljs sql">general log会比较大,所以默认市关闭的,所以最好需要的时候打开,随手关闭。如果发现query.log过大,可以手动删除。在general log打开的情况下,query.log文件类似于mysql表的lock情况,不允许修改和删除,关闭general log就可以操作了。