MySQL语句大全

1select * from emp;  #注释
2#---------------------------
3#----命令行连接MySql---------
4 
5#启动mysql服务器
6net start mysql
7 
8#关闭 
9net stop mysql
10  
11#进入
12mysql -h 主机地址 -u 用户名 －p 用户密码
13 
14#退出
15exitstatus;显示当前mysql的version的各种信息。
16 
17#---------------------------
18#----MySql用户管理---------
19 
20#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:
21mysqladmin -uroot -p123 password 456;
22 
23#增加用户
24#格式:grant 权限 on 数据库.* to 用户名@登录主机 identified by '密码'
25/*
26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：
27grant select,insert,update,delete on *.* to user1@localhost Identified by "password1";
28如果希望该用户能够在任何机器上登陆mysql，则将localhost改为"%"。
29如果你不想user1有密码，可以再打一个命令将密码去掉。
30grant select,insert,update,delete on mydb.* to user1@localhost identified by "";
31*/
32 
33grant all privileges on wpj1105.* to sunxiao@localhost identified by '123';   #all privileges 所有权限
34 
35#----------------------------
36#-----MySql数据库操作基础-----
37 
38#显示数据库
39show databases;
40 
41#判断是否存在数据库wpj1105,有的话先删除
42drop database if exists wpj1105;
43 
44#创建数据库
45create database wpj1105;
46 
47#删除数据库
48drop database wpj1105;
49 
50#使用该数据库
51use wpj1105;
52 
53#显示数据库中的表
54show tables;
55 
56#先判断表是否存在,存在先删除
57drop table if exists student;
58 
59#创建表
60create table student(
61id int auto_increment primary key,
62name varchar(50),
63sex varchar(20),
64date varchar(50),
65content varchar(100)
66)default charset=utf8;
67 
68#删除表
69drop table student;
70 
71#查看表的结构
72describe student;  #可以简写为desc student;
73 
74#插入数据
75insert into student values(null,'aa','男','1988-10-2','......');
76insert into student values(null,'bb','女','1889-03-6','......');
77insert into student values(null,'cc','男','1889-08-8','......');
78insert into student values(null,'dd','女','1889-12-8','......');
79insert into student values(null,'ee','女','1889-09-6','......');
80insert into student values(null,'ff','null','1889-09-6','......');
81#查询表中的数据
82select * from student;
83select id,name from student;
84 
85#修改某一条数据
86update student set sex='男' where id=4;
87 
88#删除数据
89delete from student where id=5;
90 
91# and 且
92select * from student where date>'1988-1-2' and date<'1988-12-1';
93 
94# or 或
95select * from student where date<'1988-11-2' or date>'1988-12-1';
96  
97#between
98select * from student where date between '1988-1-2' and '1988-12-1';
99 
100#in 查询制定集合内的数据
101select * from student where id in (1,3,5);
102 
103#排序 asc 升序  desc 降序
104select * from student order by id asc;
105 
106#分组查询 #聚合函数
107select max(id),name,sex from student group by sex;
108 
109select min(date) from student;
110 
111select avg(id) as '求平均' from student;
112 
113select count(*) from student;   #统计表中总数
114 
115select 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~
116 
117select sum(id) from student;
118 
119#查询第i条以后到第j条的数据(不包括第i条)
120select * from student limit 2,5;  #显示3-5条数据
121 
122#巩固练习
123create table c(
124 id int primary key auto_increment,
125 name varchar(10) not null,
126 sex varchar(50) ,  #DEFAULT '男' ,
127 age int unsigned, #不能为负值(如为负值 则默认为0)
128 sno int unique    #不可重复
129);
130 
131drop table c;
132desc c;
133 
134insert into c (id,name,sex,age,sno) values (null,'涛哥','男',68,1);
135insert into c (id,name,sex,age,sno) values (null,'aa','男',68,2);
136insert into c (id,name,sex,age,sno) values (null,'平平','男',35,3);
137...
138 
139select * from c;
140 
141#修改数据
142update c set age=66 where id=2;
143update c set name='花花',age=21,sex='女' where id=2
144delete from c where age=21;
145 
146#常用查询语句
147select name,age ,id from c
148select * from c where age>40 and age<60;  #and
149select * from c where age<40 or age<60;  #or
150select * from c where age between 40 and 60 #between
151select * from c where age in (30,48,68,99);     #in 查询指定集合内的数据
152select * from c order by age desc;      #order by （asc升序 des降序）
153 
154#分组查询
155select name,max(age) from c group by sex;  #按性别分组查年龄最大值
156#聚合函数
157select min(age) from c;
158select avg(age) as '平均年龄 ' from c;
159select count(*) from c;  #统计表中数据总数
160select sum(age) from c;
161 
162#修改表的名字
163#格式:alter table tbl_name rename to new_name
164alter table c rename to a;
165  
166#表结构修改
167create table test
168(
169id int not null auto_increment primary key, #设定主键
170name varchar(20) not null default 'NoName', #设定默认值
171department_id int not null,
172position_id int not null,
173unique (department_id,position_id) #设定唯一值
174);
175 
176#修改表的名字
177#格式:alter table tbl_name rename to new_name
178alter table test rename to test_rename;
179 
180#向表中增加一个字段(列)
181#格式:alter table tablename add columnname type;/alter table tablename add(columnname type);
182alter table test add  columnname varchar(20);
183 
184#修改表中某个字段的名字
185alter table tablename change columnname newcolumnname type;  #修改一个表的字段名
186alter table test change name uname varchar(50);
187 
188select * from test;
189 
190#表position 增加列test
191alter table position add(test char(10));
192#表position 修改列test
193alter table position modify test char(20) not null;
194#表position 修改列test 默认值
195alter table position alter test set default 'system';
196#表position 去掉test 默认值
197alter table position alter test drop default;
198#表position 去掉列test
199alter table position drop column test;
200#表depart_pos 删除主键
201alter table depart_pos drop primary key;
202#表depart_pos 增加主键
203alter table depart_pos add primary key PK_depart_pos
204(department_id,position_id);
205 
206#用文本方式将数据装入数据库表中（例如D:/mysql.txt）
207load data local infile "D:/mysql.txt" into table MYTABLE;
208 
209#导入.sql文件命令（例如D:/mysql.sql）
210source d:/mysql.sql;  #或者  /. d:/mysql.sql;