数据库

stuTab表名
显示数据库：show databases;
创建数据库：create database if not exists studb
操作表：use studb
显示表：show tables
创建表：create table if not exists stuTable (id int,name varchar(20),gender varchar(2))ENGINE='innoDB' default charset='utf8';
插入数据：insert into stuTable (id,name,gender) values (1,'yangshaofeng','M
显示信息：SELECT * FROM STUtABLE；
修改： update stuTable set name = 'zhangsan' where id=1;
删除： delete from stuTable where id = 1;
查看表结构：show create table sstuTable;
表的重命名：rename table stuTable to newTable;
删除表： drop table newTable；
删除数据库：drop database stu;
alter 增加字段 删除一个字段 飞字段扩充长度
修改字段或者表的编码 修改字段的名字
设置id可以自增： create table if not exists stuTable(id int not null auto_increment primary key, name varchar(2)not null) engine = 'innodb' default charset = 'utf8';
修改字段类型和名字：alter table stuTable change name name varchar(20) not null；
添加字段：alter table stuTable add(phone text);
根据id查找：select * from stuTable where id = 4;
指查找名字：select name from stuTable where phone ='125650'or phone = '120';
显示个数根据条件：select count(name) from stuTable where phone = '125650' or phone = '120';
模糊查找：select count(name) from stuTable where name like 'gao%';
根据成绩排序（升序）：select score from scoretable order by score;
降序： select score from scoretable order by score desc;
最大数：select max(score) from scoretable;
最高得分：select max(score) as '最高分' from scoretable; as是起别名的
最低分：select min(score) as '最低分' from scoretable;
平均分：select avg(score) as '平均分' from scoretable;
分数大于70并且排序：select score from scoretable where score >70 order by score;
limit从1开始取6条：select score from scoretable where score >70 order by score limit 1,6; （1是下标）
查找子字段：select score from scoreTable where stuId =(select id from stuTable where name = 'gaopeng 'limit 1,1);