简单查询练习

Posted 2020-06-22 天啊鲁

select*from fruit#查询此表所有内容

select ids,name from fruit#查询序列和名字这两列

select*from fruit where ids=‘k007‘ #查找k007信息

select*from fruit where price=‘2.4‘and source=‘烟台‘

select*from Car where name like ‘奥迪%‘

select*from car where name like ‘奥迪_%‘
 
select*from chinastates where areaname like ‘__区%‘#%为只要数据里包含此字段就查出来，_为占一个位置

排序查询

select*from chinastates order by areacode desc

select*from fruit order by price,source

统计查询

 select count(*)from nation

select count(areacode)from chinastates

select max(price)from car;

select min(price)from car;
 
select avg (price)from car;
 
select sum(price)from car;

select max(price),min(price),avg(price) from car #如果要一起查的话只有这样

分组查询

select code,brand,count(*)from car group by brand

select  price,count(*), max(price) from fruit group by price 

分页查询 

select *from car limit 3,5 #跳过几条数据取几条