unity3d--高级查询

1、--内连接查询(跟表的位置无关)

select u.name,s.grade from score as s inner join users as u on s.uid=u.id

select u.name,s.grade from users as u  inner join score as s on s.uid=u.id

2、--左外连接查询(跟表的位置有关)

select u.name,s.grade from score as s left join users as u on s.uid=u.id

select u.name,s.grade from users as u  left join score as s on s.uid=u.id

3、--右外连接查询(跟表的位置有关)

select u.name,s.grade from score as s right join users as u on s.uid=u.id

select u.name,s.grade from users as u  right join score as s on s.uid=u.id

4、--like模糊查询

select id,name from users where name like '%a%'

5、--between...and

select id,name from users where id between 1 and 2

select id,name from users where id >=1 and id<=2

6、--in

select id,name from users where id in(1,2,3)

7、--sum  avg

select sum(id) as 总和 from users

select avg(id) as 平均 from users

8、--max min

select max(id) as 最大,min(id) as 最小 from users

9、--count

select count(*) as 总人数 from users

select count(password) as 总人数 from users

10、--分组

select id,avg(id) as 平均 from users group by id

select id,avg(id) as 平均 from users group by id,name

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