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select
* from
emp; #注释#---------------------------#----命令行连接MySql---------#启动mysql服务器net start mysql#关闭 net stop mysql #进入mysql -h 主机地址 -u 用户名 －p 用户密码#退出exit#---------------------------#----MySql用户管理---------#修改密码:首先在DOS 下进入mysql安装路径的bin目录下，然后键入以下命令:mysqladmin -uroot -p123 password 456;#增加用户#格式:grant 权限 on 数据库.* to 用户名@登录主机 identified by ‘密码‘/*如，增加一个用户user1密码为password1，让其可以在本机上登录， 并对所有数据库有查询、插入、修改、删除的权限。首先用以root用户连入mysql，然后键入以下命令：grant select,insert,update,delete on *.* to user1@localhost Identified by "password1";如果希望该用户能够在任何机器上登陆mysql，则将localhost改为"%"。如果你不想user1有密码，可以再打一个命令将密码去掉。grant select,insert,update,delete on mydb.* to user1@localhost identified by "";*/grant all privileges on
wpj1105.* to sunxiao@localhost identified by
‘123‘; #all privileges 所有权限#----------------------------#-----MySql数据库操作基础-----#显示数据库show databases;#判断是否存在数据库wpj1105,有的话先删除drop database if
exists wpj1105;#创建数据库create database wpj1105;#删除数据库drop database wpj1105;#使用该数据库use wpj1105;#显示数据库中的表show tables;#先判断表是否存在,存在先删除drop table if
exists student;#创建表create table student(id int
auto_increment primary key,name varchar(50),sex varchar(20),date varchar(50),content varchar(100))default
charset=utf8;#删除表drop table student;#查看表的结构describe student; #可以简写为desc student;#插入数据insert into
student values(null,‘aa‘,‘男‘,‘1988-10-2‘,‘......‘);insert into
student values(null,‘bb‘,‘女‘,‘1889-03-6‘,‘......‘);insert into
student values(null,‘cc‘,‘男‘,‘1889-08-8‘,‘......‘);insert into
student values(null,‘dd‘,‘女‘,‘1889-12-8‘,‘......‘);insert into
student values(null,‘ee‘,‘女‘,‘1889-09-6‘,‘......‘);insert into
student values(null,‘ff‘,‘null‘,‘1889-09-6‘,‘......‘);#查询表中的数据select
* from
student;select
id,name from
student;#修改某一条数据update student set
sex=‘男‘
where id=4;#删除数据delete from
student where
id=5;# and 且select
* from
student where
date>‘1988-1-2‘
and date<‘1988-12-1‘;# or 或select
* from
student where
date<‘1988-11-2‘
or date>‘1988-12-1‘; #betweenselect
* from
student where
date between ‘1988-1-2‘
and ‘1988-12-1‘;#in 查询制定集合内的数据select
* from
student where
id in
(1,3,5);#排序 asc 升序 desc 降序select
* from
student order by
id asc;#分组查询 #聚合函数select
max(id),name,sex from
student group
by sex;select
min(date) from
student;select
avg(id) as
‘求平均‘ from student;select
count(*) from
student; #统计表中总数select
count(sex) from
student; #统计表中性别总数 若有一条数据中sex为空的话,就不予以统计~select
sum(id) from
student;#查询第i条以后到第j条的数据(不包括第i条)select
* from
student limit 2,5; #显示3-5条数据#巩固练习create table c( id int
primary key auto_increment, name varchar(10) not null, sex varchar(50) , #DEFAULT ‘男‘
, age int
unsigned, #不能为负值(如为负值 则默认为0) sno int
unique #不可重复);drop table c;desc c;insert into
c (id,name,sex,age,sno) values (null,‘涛哥‘,‘男‘,68,1);insert into
c (id,name,sex,age,sno) values (null,‘aa‘,‘男‘,68,2);insert into
c (id,name,sex,age,sno) values (null,‘平平‘,‘男‘,35,3);...select
* from
c;#修改数据update c set
age=66 where
id=2;update c set
name=‘花花‘,age=21,sex=‘女‘
where id=2delete from
c where
age=21;#常用查询语句select
name,age ,id from
cselect
* from
c where
age>40 and age<60; #andselect
* from
c where
age<40 or age<60; #orselect
* from
c where
age between 40 and 60 #betweenselect
* from
c where
age in
(30,48,68,99); #in
查询指定集合内的数据select
* from
c order by
age desc; #order by
（asc升序 des降序）#分组查询select
name,max(age) from
c group
by sex; #按性别分组查年龄最大值#聚合函数select
min(age) from
c;select
avg(age) as
‘平均年龄 ‘ from c;select
count(*) from
c; #统计表中数据总数select
sum(age) from
c;#修改表的名字#格式:alter table tbl_name rename to new_namealter table c rename to a; #表结构修改create table test(id int
not null
auto_increment primary key, #设定主键name varchar(20) not null
default ‘NoName‘, #设定默认值department_id int
not null,position_id int
not null,unique (department_id,position_id) #设定唯一值);#修改表的名字#格式:alter table tbl_name rename to new_namealter table test rename to test_rename;#向表中增加一个字段(列)#格式:alter table tablename add columnname type;/alter table tablename add(columnname type);alter table test add columnname varchar(20);#修改表中某个字段的名字alter table tablename change columnname newcolumnname type; #修改一个表的字段名alter table test change name uname varchar(50);select
* from
test;#表position 增加列testalter table position add(test char(10));#表position 修改列testalter table position modify test char(20) not null;#表position 修改列test 默认值alter table position alter test set
default ‘system‘;#表position 去掉test 默认值alter table position alter test drop default;#表position 去掉列testalter table position drop column test;#表depart_pos 删除主键alter table depart_pos drop primary key;#表depart_pos 增加主键alter table depart_pos add primary key PK_depart_pos(department_id,position_id);#用文本方式将数据装入数据库表中（例如D:/mysql.txt）load data local infile "D:/mysql.txt"
into table MYTABLE;#导入.sql文件命令（例如D:/mysql.sql）source d:/mysql.sql; #或者 /. d:/mysql.sql; |
MySQL语法大全_自己整理的学习笔记,布布扣,bubuko.com
原文地址：http://www.cnblogs.com/flying-tx/p/3766313.html
