SQL语句用法大全-查

2019-04-11  本文已影响0人  冰柠檬_705e

1.查询语句:

select  “栏目名” from “表名”

select * from A

去重distinct语句:

select distinct name from A

条件查询:Where and or

select * from A Where score >60 and score<80

函数条件查询:having

select name,sum(score) from A group by name having sum(score)>668

查询相同字段不同值:in(不连续)

select *  from A Where name in(“Leo”,“Xua”)

between(连续)

select * from A Where score between “70” and “90”

模糊查询:Like

select * from A Where name like “王%”

“A_Z”(ABZ),“A%”,“%A”,“%A%”;

排序:order by (des,asc)默认asc;

select * from A order by age desc

函数:avg,count,max,min,sum

select 函数(栏目)  from A

select count(score) from A where score>=80

分组:group by

select name,sum(score) from A group by name;

别名:as

select 表别名.栏目名 栏目别名 from 表名 as 表别名

select a.name as “姓名” from table as a

多表查询:join

select a.name,b.class,sum(a.score)

from aaa as a,bbb as b

where a.name=b.name

group by a.name;

外连接:outer join

left outer join 左外

right outer join 右外

full outer join 全外

select a.name,b.class,sum(a.score)

from aaa as A right join bbb as b

on a.name=b.name

group by a.name

子查询:

select name,sum(score)

from a

where name in

(select name from b where class=“一班”)

group by name

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