MYSQL 相关

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发布时间：2019-05-27

本文共 6813 字，大约阅读时间需要 22 分钟。

1.开启事务：

行级锁

session1:

#begin;

#select *from pub_sev_db.t_push_log where FmsgId = 3 for update;//注意调节语句必须为主键才能执行行锁定

#commit

session2:

可以执行select语句，但无法修改FmsgId = 3的语句：

比如执行：

update pub_sev_db.t_push_log set Fmodify_time=now() where FmsgId=3;

会在这里阻塞，

同理

begin;

select *from pub_sev_db.t_push_log where FmsgId = 3 for update;//也会阻塞

commit

直到session1 commit事务或是事务被结束！！！

1.添加PRIMARY KEY（主键索引）

mysql>ALTER TABLE `table_name` ADD PRIMARY KEY ( `column` )

2.添加UNIQUE(唯一索引)
mysql>ALTER TABLE `table_name` ADD UNIQUE ( `column` )

3.添加INDEX(普通索引)

mysql>ALTER TABLE `table_name` ADD INDEX index_name ( `column` )

4.添加FULLTEXT(全文索引)

mysql>ALTER TABLE `table_name` ADD FULLTEXT ( `column`)

5.添加多列索引
mysql>ALTER TABLE `table_name` ADD INDEX index_name ( `column1`, `column2`, `column3` )

MySQL创建用户与授权方法

一, 创建用户:

命令:CREATE USER 'username'@'host' IDENTIFIED BY 'password';

说明:username - 你将创建的用户名, host - 指定该用户在哪个主机上可以登陆,如果是本地用户可用localhost, 如果想让该用户可以从任意远程主机登陆,可以使用通配符%. password - 该用户的登陆密码,密码可以为空,如果为空则该用户可以不需要密码登陆服务器.

例子: CREATE USER 'dog'@'localhost' IDENTIFIED BY '123456';

CREATE USER 'pig'@'192.168.1.101_' IDENDIFIED BY '123456';

CREATE USER 'pig'@'%' IDENTIFIED BY '123456';

CREATE USER 'pig'@'%' IDENTIFIED BY '';

CREATE USER 'pig'@'%';

二,授权:

命令:GRANT privileges ON databasename.tablename TO 'username'@'host'

说明: privileges - 用户的操作权限,如SELECT , INSERT , UPDATE 等(详细列表见该文最后面).如果要授予所的权限则使用ALL.;databasename - 数据库名,tablename-表名,如果要授予该用户对所有数据库和表的相应操作权限则可用*表示, 如*.*.

例子: GRANT SELECT, INSERT ON test.user TO 'pig'@'%';

GRANT ALL ON *.* TO 'pig'@'%';

注意:用以上命令授权的用户不能给其它用户授权,如果想让该用户可以授权,用以下命令:

GRANT privileges ON databasename.tablename TO 'username'@'host' WITH GRANT OPTION;

三.设置与更改用户密码

命令:SET PASSWORD FOR 'username'@'host' = PASSWORD('newpassword');如果是当前登陆用户用SET PASSWORD = PASSWORD("newpassword");

例子: SET PASSWORD FOR 'pig'@'%' = PASSWORD("123456");

四.撤销用户权限

命令: REVOKE privilege ON databasename.tablename FROM 'username'@'host';

说明: privilege, databasename, tablename - 同授权部分.

例子: REVOKE SELECT ON *.* FROM 'pig'@'%';

注意: 假如你在给用户'pig'@'%'授权的时候是这样的(或类似的):GRANT SELECT ON test.user TO 'pig'@'%', 则在使用REVOKE SELECT ON *.* FROM 'pig'@'%';命令并不能撤销该用户对test数据库中user表的SELECT 操作.相反,如果授权使用的是GRANT SELECT ON *.* TO 'pig'@'%';则REVOKE SELECT ON test.user FROM 'pig'@'%';命令也不能撤销该用户对test数据库中user表的Select 权限.

具体信息可以用命令SHOW GRANTS FOR 'pig'@'%'; 查看.

五.删除用户

命令: DROP USER 'username'@'host';

附表:在MySQL中的操作权限

`ALTER`	Allows use of `ALTER TABLE`.
`ALTER ROUTINE`	Alters or drops stored routines.
`CREATE`	Allows use of `CREATE TABLE`.
`CREATE ROUTINE`	Creates stored routines.
`CREATE TEMPORARY TABLE`	Allows use of `CREATE TEMPORARY TABLE`.
`CREATE USER`	Allows use of `CREATE USER`, `DROP USER`, `RENAME USER`, and `REVOKE ALL PRIVILEGES`.
`CREATE VIEW`	Allows use of `CREATE VIEW`.
`DELETE`	Allows use of `DELETE`.
`DROP`	Allows use of `DROP TABLE`.
`EXECUTE`	Allows the user to run stored routines.
`FILE`	Allows use of `SELECT`... `INTO OUTFILE` and `LOAD DATA INFILE`.
`INDEX`	Allows use of `CREATE INDEX` and `DROP INDEX`.
`INSERT`	Allows use of `INSERT`.
`LOCK TABLES`	Allows use of `LOCK TABLES` on tables for which the user also has `SELECT` privileges.
`PROCESS`	Allows use of `SHOW FULL PROCESSLIST`.
`RELOAD`	Allows use of `FLUSH`.
`REPLICATION`	Allows the user to ask where slave or master
`CLIENT`	servers are.
`REPLICATION SLAVE`	Needed for replication slaves.
`SELECT`	Allows use of `SELECT`.
`SHOW DATABASES`	Allows use of `SHOW DATABASES`.
`SHOW VIEW`	Allows use of `SHOW CREATE VIEW`.
`SHUTDOWN`	Allows use of `mysqladmin shutdown`.
`SUPER`	Allows use of `CHANGE MASTER`, `KILL`, `PURGE MASTER LOGS`, and `SET GLOBAL` SQL statements. Allows `mysqladmin debug` command. Allows one extra connection to be made if maximum connections are reached.
`UPDATE`	Allows use of `UPDATE`.
`USAGE`	Allows connection without any specific privileges.

#############################################################

常用语句

#SELECT NOW()

#SELECT unix_timestamp(now()) from sys.sys_config limit 1

#create database pub_sev_db;

use pub_sev_db;

CREATE TABLE `pub_sev_db`.`t_access_token` (

`Fappid` VARCHAR(64) NOT NULL,

`Fsecret` VARCHAR(64) NOT NULL,

`Fappid_Type` TINYINT(2) NULL,

`Faccess_token_refresh` TINYINT(2) NULL,

`Fjsapi_ticket_refresh` TINYINT(2) NULL,

`Faccess_token` VARCHAR(1024) NULL,

`Facctok_expires` INT(11) NULL,

`Facctok_invalid_stamp` INT(11) NULL,

`Fjsapi_ticket` VARCHAR(1024) NULL,

`Fticket_expires` INT(11) NULL,

`Fticket_invalid_stamp` INT(11) NULL,

`Fcreate_time` DATETIME NULL,

`Fmodify_time` DATETIME NULL,

`Freserved_1` INT(11) NULL,

`Freserved_2` INT(11) NULL,

`Freserved_3` VARCHAR(128) NULL,

`Freserved_4` VARCHAR(128) NULL,

`Freserved_5` DATETIME NULL,

`Freserved_6` DATETIME NULL,

PRIMARY KEY (`Fappid`))

ENGINE = InnoDB

DEFAULT CHARACTER SET = utf8;

#明文

insert into pub_sev_db.t_access_token(Fappid,Fsecret,Fappid_Type,Faccess_token_refresh,Fjsapi_ticket_refresh,Fcreate_time,Fmodify_time) values

('wxb373aef795a268','05d7159b5430690f9c938b3',2,1,1,now(),now());

#加密

insert into pub_sev_db.t_access_token(Fappid,Fsecret,Fappid_Type,Faccess_token_refresh,Fjsapi_ticket_refresh,Fcreate_time,Fmodify_time) values

('wxb373aefa21868','B095K72CsZPTYFr0EEt0kde+jArPfINkn8BTh3Y8gjV1l+ztPkOM5Q==',2,1,1,now(),now());

#update `pub_sev_db`.`t_access_token` set Fmodify_time= now() where Fappid= 'wxb373aef795a21868' ;

#select * from `pub_sev_db`.`t_access_token`;

#修改字段属性

ALTER TABLE `pub_sev_db`.`t_access_token` CHANGE COLUMN `Fsecret` `Fsecret` VARCHAR(72) NOT NULL ;

#删除一条记录

delete from pub_sev_db.t_access_token where Fappid = 'wxb373aef795a21868';

#修改表名

ALTER TABLE `pub_sev_db`.`t_push_log` RENAME TO `pub_sev_db`.`t_push_log_1` ;

select now();

CREATE TABLE `pub_sev_db`.`t_push_log` (

`FmsgId` INT(11) NOT NULL AUTO_INCREMENT,

`Fappid` VARCHAR(64) NULL,

`Fopenid` VARCHAR(72) NULL,

`FpushMsgId` VARCHAR(72) NULL,

`FpushResult` VARCHAR(32) NULL,

`FpushResultDec` VARCHAR(128) NULL,

`FpushStatus` TINYINT(5) NULL,

`FpushCnt` TINYINT(5) NULL,

`Fmsg` VARCHAR(3096) NULL,

`Fcreate_time` DATETIME NULL,

`Fmodify_time` DATETIME NULL,

`Freserved_1` INT(11) NULL,

`Freserved_2` INT(11) NULL,

`Freserved_3` VARCHAR(128) NULL,

`Freserved_4` VARCHAR(128) NULL,

`Freserved_5` DATETIME NULL,

`Freserved_6` DATETIME NULL,

PRIMARY KEY (`FmsgId`))

ENGINE = InnoDB

DEFAULT CHARACTER SET = utf8;

#insert into pub_sev_db.t_push_log(Fappid,Fopenid,FpushResult,FpushResultDec,FpushStatus,FpushCnt,Fmsg,Fcreate_time,Fmodify_time) values('wxb373aef795a21868','121334fdgsrqag','pushing','null',1,0,'msgvalue:hello',now(),now());

#返回为当前会话的所有作用域中的任何表最后生成的标识值

# SELECT @@Identity AS FmsgId;

#SELECT * FROM pub_sev_db.t_push_log;

#返回为当前会话的所有作用域中的任何表最后生成的标识值

#SELECT distinct @@Identity AS FmsgId from pub_sev_db.t_push_log;

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