添加表数据
1 insert into car values(' ',' ',' ', ' ',' ');
2 insert into car(字段1，字段2，....) values(值1，值2，.....);
3 insert into car set 字段1=值一，字段2=值2，...；
修改表数据
update car set 字段1= 值 where 字段2=值
删除表数据
delete from 表名 where 字段1 = 值
================简单查询===============
1最简单查询
select * from car;
2查询指定列
select name，oil，powers from car；
3 对查出的列名修改名字
select name as ' 车名’，oil as '油耗’，powers as '动力’ from car;
4 按条件查询
select name ，oil，powers from car where oil = 8.7；
5 多条件查询
select name， oil， powers from car where oil=8.7 or powers =160；
select name，oil， powers from car where oil = 8.7 and powers =160；
6 范围查询
select * from car where price>=40and price<=60;
select * from car where price between 40 and 60；
7离散查询
select * from car where powers = 130 or powers=150 or powers=170；
select *from car where powers in （130，150，170）；
select * from car where powers not in (130,150,170）；
8模糊查询
select *from car where name like ‘ %宝马%’；
select * from car where name like “_宝马%"; _代表一个字符
9 排序查询 asc 升序 desc 降序 order 排队
select * from car order by oil asc;
select * from car order by brand asc,price desc;
10去重复查询 distinct
select distinct brand from car；
11分页查询
select* from car limit 10，5；
n:m=5
limit (n-1)*m,m;
12 聚合函数查询
count(列名）sum(列名) avg(列名) max(列名) min(列名)
select count(*) from car;
select sum(price) from car;
select avg(price) from car;
select max(price) from car;
select min(price) from car;