MySQL數據庫的高級操做

1.數據備份與還原

（1）備份
mysqldump:
mysqldump -u username -p password dbname [tbname1 [tbname2....] ]> filename.sql

mysqldump -u root -p mydb2 > C:\mysql\dump\mydb2_dump.sql

（2）恢復：只能恢復數據庫的表和記錄，不能恢復數據庫自己

mysql:方法一
              mysql -u username -p password [dbname] < filename.sql

mysql：方法二，source命令
在MySQL命令提示符下：建立數據庫 進入數據庫 source xxx.sql 文件 將備份的sql文件在當前位置執行
source filename.sql //路徑

2.user表

3.建立普通用戶

（1）使用GRANT語句建立用戶

GRANT privileges ON dtabase.table
TO 'username' @ 'hostname' [IDENTIFIED BY [PASSWORD] 'password'] [,'username' @ 'hostname' [IDENTIFIED BY [PASSWORD] 'password']]...............

---

grant select on mydb2.* to 'haha' @'localhost' identified by '123456';

//錯誤

（2）使用CREATE語句

CREATE USER 'username'@'hostname' [IDENTIFIED BY [PASSWORD] 'password'] [,'username' @ 'hostname' [IDENTIFIED BY [PASSWORD] 'password']]...............

create user 'haha'@'localhost' identified by '123456';

(3) 使用INSERT語句

4.刪除普通用戶

~ROP USER 'username'@'hostname' [,'username'@'hostname'];

drop user 'ha'@'localhost';

~ELETE FROM mysql.user WHERE Host= 'hostname' AND User = 'username';

delete from mysql.user where host = 'localhost' and user = 'ha';

flush privileges; #因爲直接對user表執行操做，要從新加載用戶權限

5.修改用戶密碼

（1）修改root用戶密碼

+++++++++++++++++++++++++++++++++++++++++++++++

UPDATE mysql.user set Password = PASSWORD('new_password') WHERE User='username' and Host='hostname';

FLUSH PRIVILEGES;

update mysql.user set password=PASSWORD('QWE123!@#') where user='root' and host='localhost';

flush privileges;
+++++++++++++++++++++++++++++++++++++++++++++
//不成功

（2）root用戶修改普通用戶密碼
SET PASSWORD FOR 'username'@'hostname'=PASSWORD('new_password');

set password for 'haha'@'localhost'=PASSWORD('123');
+++++++++++++++++++++++++++++++++++++++
//不成功

（3）普通用戶修改密碼

SET PASSWORD=PASSWORD('new_password');

6.授予權限：使不一樣用戶有不一樣權限

（1）GRANT privileges [ (columns) ] [,privileges[(columns)]] ON database.table TO 'username'@'hostname' [IDENTIFIED BY [PASSWORD] 'password' ] [ 'username'@'hostname' [IDENTIFIED BY [PASSWORD] 'password' ]]...........
[WITH with_option [with_option]...]

with_option參數以下：
（1）GRANT OPTION：將本身的權限授予其餘用戶
（2）MAX_QUERIES_PER_HOUR count：設置每小時最大查詢次數count。
（3）MAX_UPDATES_PER_HOUR count：設置每小時最多可執行多少次更新
（4）MAX_CONNECTIONS_PER_HOUR count：設置每小時最大鏈接數量
（5）MAX_USER_CONNECTIONS：設置每一個用戶最多能夠同時創建鏈接數量

GRANT INSERT,SELECT ON mydb2.star TO 'haha'@'localhost' IDENTIFIED BY '123456'
WITH GRANT OPTION;

++++++++++++++++++++++++++++++++++++++++++++
//不成功

7.查看權限

(1) SHOW GRANTS FOR 'username'@'hostname';
show grants for 'haha'@'localhost';

8.收回權限

REVOKE privileges [ (columns) ] [,privileges[(columns)]] ON database.table FROM 'username'@'hostname' [,'username'@'hostname' ]....