mysql> -uroot -p123456 登陆
mysql> grant all on test.* to 'pengshiyu'@'localhost'
-> identified by '123456'; 创建用户
mysql> quit 退出
mysql> show databases; 查看数据库
mysql> create database test; 创建数据库
mysql> create database test charset utf8; 指定字符集支持中文
mysql> show create database test; 查看数据库信息
mysql> drop database test; 删除数据库
mysql> use test; 进入数据库
mysql> create table student(
-> id int auto_increment,
-> name char(32) not null,
-> age int not null,
-> register_data date not null,
-> primary key (id)
-> ); 创建表
mysql> show tables; 查看表
mysql> desc student; 查看表结构
mysql> describe student; 查看表结构
mysql> show columns from student; 查看表结构
mysql> insert into student(name, age, register_data)
-> values('tom', 27, '2018-06-25'); 增加记录
mysql> select * from student; 查询数据
mysql> select * from student\G 按行输出
mysql> select * from student limit 3; 限制查询数量
mysql> select * from student limit 3 offset 5; 丢弃前5条数
mysql> select * from student where id > 3; 条件查询
mysql> select * from student where register_data like "2018-06%"; 模糊查询
mysql> update student set name = 'cxx' where id = 10; 修改
mysql> delete from student where id = 10; 删除
mysql> select * from student order by age; 排序默认ascend
mysql> select * from student order by age desc; 降序descend
mysql> select age,count(*) as num from student group by age; 分组
mysql> select name, sum(age) from student group by name with rollup; 汇总
mysql> select coalesce(name,'sum'), sum(age) from student
-> group by name with rollup; 汇总取别名
mysql> alter table student add sex enum('M','F'); 增加字段
mysql> alter table student drop sex; 删除字段
mysql> alter table student modify sex enum('M','F') not null; 修改字段类型
mysql> alter table student modify sex
-> enum('M','F') not null default 'M'; 设置默认值
mysql> alter table student change sex gender
-> enum('M','F') not null default 'M'; 修改字段名称
mysql> create table study_record(
-> id int not null primary key auto_increment,
-> day int not null,
-> stu_id int not null,
-> constraint fk_student_key foreign key (stu_id) references student(id)
-> );命名外键约束
创建表
mysql> create table A(a int not null);
mysql> create table B(b int not null);
插入数据
mysql> insert into A(a) values (1);
mysql> insert into A(a) values (2);
mysql> insert into A(a) values (3);
mysql> insert into A(a) values (4);
mysql> insert into B(b) values (3);
mysql> insert into B(b) values (4);
mysql> insert into B(b) values (5);
mysql> insert into B(b) values (6);
mysql> insert into B(b) values (7);
交集 内连接
mysql> select * from A inner join B on A.a = B.b;
mysql> select a.*, b.* from A inner join B on A.a = B.b;
差集
mysql> select * from A left join B on A.a =B.b; 左外连接
mysql> select * from A right join B on A.a =B.b; 右外连接
并集
mysql> select * from a left join b on a.a=b.b union
-> select * from a right join b on a.a = b.b; 全连接
mysql> begin; 开始事务
mysql> rollback; 回滚事务
mysql> commit; 提交事务
mysql> show index from student; 查看索引
mysql> create index name_index on student(name(10)); 创建索引
mysql> drop index name_index on student;删除索引
