帽帽云
1.查询所有数据
| select * from Info 查所有数据
select Code,Name from Info 查特定列 |
2.根据条件查询
| select * from Info where Code=’p001′ 一个条件查询
select * from Info where Code=’p001′ and Nation=’n001′ 多条件 并关系 查询 select * from Info where Name=’胡军’ or Nation=’n001′ 多条件 或关系 查询 select * from Car where Price>=50 and Price<=60 范围查询 select * from Car where Price between 50 and 60 范围查询 |
3.模糊查询
| select * from Car where Name like ‘%型’ %通配符代表任意多个字符
select * from Car where Name like ‘%奥迪%’ _通配符代表任意一个字符 select * from Car where Name like ‘_马%’ |
4.排序
| select * from Car order by Price asc 按照价格升序排列
select * from Car order by Price desc 按照价格降序排列 select * from Car order by Price,Oil 按照两列进行排序，前面的为主要的 |
5.统计函数
| select count(Code) from Car 查询表中有多少条数据
select max(Price) from Car 取价格的最大值 select min(Price) from Car 取价格的最小值 select sum(Price) from Car 取价格的总和 select avg(Price) from Car 取价格的平均值 |
6.分组查询
| select Brand from Car group by Brand having count(*)>2 查询所有系列中数量大于2的 |
7.分页查询
| select * from Car limit 0,5 跳过几条数据取几条数据 |
8.去重查询
| select distinct Brand from Car |
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