SQL简记（一）

1 Mysql相关

1 .1 启动/停止命令

win: net start/stop mysql
linux: service mysqld start/stop

1.2 用户

创建用户：create user szh@localhost identified by "123456";
授权：grant all on . to 'szh'@'localhost' identified by '123456'; 刷新：flush privileges;
设置密码：set password for szh@localhost=password("123456");
解除授权：revoke all on . from local@localhost;
更多请查看这里

1.3 字符集

1）查看字符集：show variables like '%char%';
2）修改字符集（配置文件）
复制my-default.ini为my.ini，按照下面的进行修改和补全，保存后进行重启

# For advice on how to change settings please see
# http://dev.mysql.com/doc/refman/5.7/en/server-configuration-defaults.html
# *** DO NOT EDIT THIS FILE. It's a template which will be copied to the
# *** default location during install, and will be replaced if you
# *** upgrade to a newer version of MySQL.

[mysqld]
character-set-server=utf8

# Remove leading # and set to the amount of RAM for the most important data
# cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.
# innodb_buffer_pool_size = 128M

# Remove leading # to turn on a very important data integrity option: logging
# changes to the binary log between backups.
# log_bin

# These are commonly set, remove the # and set as required.
# basedir = D:\SoftWare\JAVA\JavaWeb\mysql-5.7.13-win32\mysql-5.7.13-win32
# datadir = D:\SoftWare\JAVA\JavaWeb\mysql-5.7.13-win32\mysql-5.7.13-win32\data
# port = .....
# server_id = .....
[client]
loose-default-character-set=utf8
default-character-set=utf8
[mysql]
default-character-set=utf8

# Remove leading # to set options mainly useful for reporting servers.
# The server defaults are faster for transactions and fast SELECTs.
# Adjust sizes as needed, experiment to find the optimal values.
# join_buffer_size = 128M
# sort_buffer_size = 2M
# read_rnd_buffer_size = 2M 

# sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES

3）修改数据库的字符集
alter database db_name character set utf8;
4）修改表格的字符集
alter table tb_name character set utf8 collate utf_general_ci;

2 SQL相关

2.1 查询

查询

2.2 过滤：where后面的条件

过滤

待续...