mysql字符集以及乱码实战

单实例启动
/etc/init.d/mysqld start
1启动mysql_safe --datadir =? --pid=? other args >/dev/null 2>&1 &
2 初始化数据库时mysql输出给出的启动方法
mysql_safe --user=mysql&
提示：
当找回root密码时，会经常使用mysql_safe --user=mysql &带参数启动
2当我们自己开发启动脚本启动数据库时可能会用到这个启动方法
3 /etc/init.d/mysqld 和mysql_safe -user=mysql启动实质是一样的
三常规方法关闭数据库
etc/init.d/mysqld stop
强制关闭数据库的方法
killall mysqld直到no process 就完成了
pkill mysqld
killall -9 mysqld
找回丢失的mysql root密码
启动修改丢失的mysql单实例root的方法
1首先停止数据库
/etc/init.d/mysqld stop 多实例killall mysqld
2使用--skip-grant-tables 启动数据库，胡月授权登录验证
mysqld_safe --skip-grant-tables --user=mysql &
多实例 mysqld_safe --defaults-file=/data/3306/my.cnf --skip-grant-table &
或者mysql -uroot -p -S /data/3306/mysql.socket
mysql

update password
不能set password=passwd('')
flush privileges
quit
重启
mysqladmin shutdown
/etc/init.d/mysqld start
mysqladmin -uroot -p‘密码’ shutdown
/etc/init.d/mysqld start
#######################################################################没做#########################################################

mysql登录方式
mysql
mysql -uroot
mysql -uroot -p
mysql -uroot -p'admin'
HISTORY=ignorespace 不记录铭感记录如
history -c
history -d 2清除前两项记录
cat /root/.mysqlhistory
cat /root/.bash里有history记录linux命令
mysql提示符修改\u系统
mysql> prompt \u@root  \r:\m:\s->  
PROMPT set to '\u@root  \r:\m:\s->'
或者my.cnf [mysql]里添加prompt \u@root  \r:\m:\s->  
多实例而远程连接 mysql -uroot -padmin -h 127.0.0.1 -P3306
学会mysql帮助命令
linux man help内置命令 help history

oot@root  10:36:54->help
nowarning (\w) Don't show warnings after every statement.

For server side help, type 'help contents'

root@root  10:38:13->help show
Name: 'SHOW'
root@root 10:38:19->
查看权限
help show
help show grants
help show grants for 'root'@'localhost'

退出mysql exit quit ctr+c ctr+d
安全设置
a 为用户设置密码
b删除无用的mysql库内账号
c删除默认存在的test数据库
更安全的做法是删除root用户delete from mysql.user
2>新增system并且提升为超级管理员用户
mysql> grant all privileges on *.* to system@'localhost' identified by 'admin' with grant option
    -> ;revoke
Query OK, 0 rows affected (0.02 sec)
为管理员root设置密码
mysqladmin -uroot password'admin'
mysqladmin -uroot -p'admin'  password'admin' -S /data/3308/mysql.socket
修改
mysqladmin -uroot -padmin password'admin'
mysqladmin -uroot -p'admin'  password'admin' -S /data/3308/mysql.socket
mysql>update mysql.user set password=password('admin') where user='root'
mysql>flush privileges;
第三种
mysql>set password =pasword('admin')
找回丢失的密码
mysql> create database tt;
Query OK, 1 row affected (0.05 sec)

mysql> show  create database tt;
+----------+---------------------------------------------------------------+
| Database | Create Database                                               |
+----------+---------------------------------------------------------------+
| tt       | CREATE DATABASE `tt` /*!40100 DEFAULT CHARACTER SET latin1 */ |
+----------+---------------------------------------------------------------+
1 row in set (0.05 sec)

mysql> create database tt_gbk DEFAULT CHARACTER SET gbk collate gbk_chinese _ci;
mysql> create database tt_gbk DEFAULT CHARACTER SET utf8 collate utf8_general_ci;
Query OK, 1 row affected (0.00 sec)

如果编译的时候制定了数据库的字符集就不需要制定字符集了
根据开发环境制定字符集 或编译的时候制定
编译的时候没有制定字符集或者开发制定了不同的字符集， 那么指定字符集创建即可
显示数据库
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| test               |
| tt                 |
| tt_gbk             |
+--------------------+
6 rows in set (0.04 sec)
mysql> show databases like '%tt%'
    -> ;
+-----------------+
| Database (%tt%) |
+-----------------+
| tt              |
| tt_gbk          |
+-----------------+
2 rows in set (0.05 sec)
当前数据库
mysql> use tt
Database changed
mysql> select database();查看当前连接的数据库
+------------+
| database() |
+------------+
| tt         |
+------------+
1 row in set (0.00 sec)
删除数据库
mysql> drop database tt_gbk;
Query OK, 0 rows affected (0.00 sec)

连接数据库
mysql> use tt
mysql> select now();
+---------------------+
| now()               |
+---------------------+
| 2015-12-28 00:16:59 |
+---------------------+
1 row in set (0.00 sec)

mysql> select user();
+----------------+
| user()         |
+----------------+
| root@localhost |
+----------------+
1 row in set (0.00 sec)

mysql> select version();
+------------+
| version()  |
+------------+
| 5.5.32-log |
+------------+
1 row in set (0.00 sec)
创建mysql用户及其授予权限
create user 'jeffrey'@'localhost' identified by 'mypass';
grant all on db1.* to 'jeffrey'@'localhost'
grant select on db2.invoice to 'jeffrey' @'localhost'
grant usage on *.* to 'jeffrey'@'localhost' with max_queries_per_hour 90
可以通过查看grant 命令帮助
mysql> grant all privileges on test.* to test02@'localhost' identified by 'admin';
Query OK, 0 rows affected (0.04 sec)

mysql> select user,host from mysql.user;
+--------+-----------------------+
| user   | host                  |
+--------+-----------------------+
| root   | 127.0.0.1             |
| root   | ::1                   |
|        | localhost             |
| root   | localhost             |
| system | localhost             |
| test02 | localhost             |
|        | localhost.localdomain |
| root   | localhost.localdomain |
+--------+-----------------------+
8 rows in set (0.00 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)
mysql> show grants for test02@localhost;
+---------------------------------------------------------------------------------------------------------------+
| Grants for test02@localhost                                                                                   |
+---------------------------------------------------------------------------------------------------------------+
| GRANT USAGE ON *.* TO 'test02'@'localhost' IDENTIFIED BY PASSWORD '*4ACFE3202A5FF5CF467898FC58AAB1D615029441' |
| GRANT ALL PRIVILEGES ON `test`.* TO 'test02'@'localhost'                                                      |
+---------------------------------------------------------------------------------------------------------------+
2 rows in set (0.00 sec)
useage 什么都不能做