连接信息
use information_schema
;
select * from information_schema
.`PROCESSLIST
` where info
is not null;
注释查询
select table_name
,column_name
,column_comment
from information_schema
.columns
where table_schema
='dbA' and COLUMN_NAME
like '%columnName%';
select table_name 表名
,TABLE_COMMENT 表注释
from INFORMATION_SCHEMA
.TABLES
Where table_schema
= 'dbA' AND table_name
="tableA";
select table_name
,column_name
,column_comment
from information_schema
.columns
where table_schema
='dbA' and column_comment
like '%注释%';
数据库配置
show global status like 'Thread%';
show variables
like '%connect%';
变量
set @uname='张三';
UPDATE table p
SET p
.user_name
=@uname WHERE p
.no='1234';
慢查询
use mysql
;
show global variables
like '%log_output%';
set global log_output
= 'TABLE';
set global log_queries_not_using_indexes
=off; 慢查询中不写入无索引查询的日志。
show variables
like "%slow%";
set global slow_query_log
= ON;
set long_query_time
=1; 开启慢查询，超过
1秒的记录入日志
mysqldumpslow
-s t
-t
2 /tmp
/mysqlslow
.log 查看慢查询日志
（
-s
, 是表示按照何种方式排序，c、t、l、r分别是按照记录次数、时间、查询时间、返回的记录数来排序，ac、at、al、ar，表示相应的倒叙；
-t
, 是
top n的意思，即为返回前面多少条的数据；
-g
, 后边可以写一个正则匹配模式，大小写不敏感的；
）
普通日志
show global variables
like '%general%';
set global general_log
= ON;
SELECT argument
from general_log
where argument
not like '%SELECT%' AND (argument
like '%UPDATE%' OR argument
like '%INSERT%') order by event_time
desc;
密码重置
MYSQL密码重置：
mysqld_safe
mysql
-u root mysql
update user set Password
=PASSWORD
('newPassword') where User='root';
flush
privileges;
