mysql常用

 

#数据库主从

show processlist;

show master statusG;

show variables like 'server_id';

flush privileges;

select user,host,password from mysql.user;

#主上执行

grant replication slave,file on *.* to 'slavebak'@'1.1.1.1' identified by 'newpasswd';

#在从上执行以下

change master to master_host='1.1.1.1', master_user='test', master_password='newpasswd', master_log_file='mysql-bin.000005', master_log_pos=340;

 

change master to master_host='1.1.1.1', master_user='slavebak', master_password='newpasswd',MASTER_AUTO_POSITION=1;

#权限赋予

flush tables with read lock;

unlock tables;

 

CREATE USER auditor@localhost IDENTIFIED BY 'newpasswd';

GRANT ALL ON yiibaidb.* TO auditor@localhost;

grant create,execute,insert,delete,select on *.* to usertest1@localhost;

grant create,execute,insert,delete,select on *.* to usertest1@'%' identified by 'newpasswd';

SHOW GRANTS FOR usertest1@'%';

#字符集编码修改

create database if not exists test3 character set utf8;

alter database test3 character set latin1;

#修改root密码

ALTER USER 'root'@'localhost' IDENTIFIED BY '新密码';

update user set password=password("12345") where user="root";

 

忘记root密码，停数据库 使用

mysqld_safe --skip-grant-tables

 

set password = password("newpasswd");

#允许远程登录

GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY '1234' WITH GRANT OPTION;  

flush privileges;  

 

#查看同步状态参数

Seconds_Behind_Master，为0说明同步完成

pt-table-checksum    检查数据一致性，会有影响（注意）。

#查看数据库表的行数

use information_schema;

select table_name,table_rows from tables where TABLE_SCHEMA = 'mysql' order by table_rows desc;

 

查看单表行数

select table_name,table_rows from information_schema.tables where TABLE_NAME = 'history' order by table_rows;

select table_name,table_rows from tables where TABLE_NAME = 'orders' order by table_rows ;

select table_name,table_rows from tables where TABLE_NAME = 'books' order by table_rows ;

select table_name,table_rows from tables where TABLE_NAME = 'book_parts' order by table_rows ;

#查询数据库中的存储过程和函数

select `name` from mysql.proc where db = 'xx' and `type` = 'PROCEDURE' ;        #存储过程

select `name` from mysql.proc where db = 'xx' and `type` = 'FUNCTION'   ;       #函数

show procedure status;                                                           #存储过程

show function status;                                                            #函数

查看存储过程或函数的创建代码

show create procedure proc_name;

show create function func_name;

 

查看视图

SELECT * from information_schema.VIEWS   #视图

SELECT * from information_schema.TABLES  #表

查看触发器

SHOW TRIGGERS [FROM db_name] [LIKE expr]

SELECT * FROM triggers T WHERE trigger_name=”mytrigger” G

#查看数据库大小

1、进入information_schema 数据库（存放了其他的数据库的信息）

use information_schema;

2、查询所有数据的大小：

select concat(round(sum(data_length/1024/1024),2),'MB') as data from tables;

3、查看指定数据库的大小：

比如查看数据库home的大小

select concat(round(sum(data_length/1024/1024),2),'MB') as data from information_schema.tables where table_schema='home';

4、查看指定数据库的某个表的大小

比如查看数据库home中 members 表的大小

select concat(round(sum(data_length/1024/1024),2),'MB') as data from information_schema.tables where table_schema='home' and table_name='members';

5，看每个表大小

SELECT TABLE_NAME,DATA_LENGTH+INDEX_LENGTH,TABLE_ROWS,concat(round((DATA_LENGTH+INDEX_LENGTH)/1024/1024,2), 'MB') as data FROM TABLES WHERE TABLE_SCHEMA='mysql';

设置从机的复制模式

change master to master_auto_position=0;

reset slave all ;

查看是否安全保护

SHOW VARIABLES LIKE 'sql_safe_updates';

select @@sql_safe_updates;

检查数据一致性

pt-table-checksum --nocheck-replication-filters --no-check-binlog-format --create-replicate-table --databases=ifeng  --tables=  -u root -p eba41b786d57213b09b12ca38ed9fa63 -h 127.0.0.1

 

pt-table-checksum --nocheck-replication-filters --no-check-binlog-format

--replicate=ifeng --create-replicate-table --databases=ifeng  --tables=book_parts -u chechdb -p 123comER -h 10.89.11.152

 

grant all on *.* to chechdb@'10.89.%.%' identified by '123comER';

 

死锁

show  processlist;

1：查看当前的事务

SELECT * FROM INFORMATION_SCHEMA.INNODB_TRX;

2：查看当前锁定的事务

SELECT * FROM INFORMATION_SCHEMA.INNODB_LOCKS;

3：查看当前等锁的事务

SELECT * FROM INFORMATION_SCHEMA.INNODB_LOCK_WAITS;

sql

后10条数据

select id,createTime from message_filesn order by id desc  limit 10;

 

select id,createTime from message_filesn where createTime < DATE_SUB(CURDATE(),INTERVAL 1 day) order by id asc limit 10;

 

SELECT DATE_SUB(CURDATE(),INTERVAL 10 day)  2018-08-19

SELECT DATE_SUB(CURDATE(),INTERVAL 1 year)  2017-08-29

SELECT DATE_SUB(CURDATE(),INTERVAL 3 month) 2018-05-29

SELECT DATE_SUB(CURDATE(),INTERVAL -1 month) 2018-09-29

释放表空间

optimize table tables_name;

 

改字符集

SET character_set_client = utf8;

SET character_set_results = utf8;

SET character_set_connection = utf8;

SET character_set_database = utf8;

SET character_set_server = utf8;

SET character_set_system = utf8;

 

 

改表名

alter table message_filesntest rename to message_filesn ;