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

    原文地址：https://www.cnblogs.com/qinqinmeiren/archive/2011/05/21/2151693.html