MySQL常用语句简介

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