sql列转行1

[sql]代码库

insert into tb(id,product,area,num)  
select 1,'A','长沙',1 from dual union   
select 2,'A','长沙',2 from dual union   
select 3,'A','北京',3 from dual union   
select 4,'A','北京',4 from dual union   
select 5,'B','上海',1 from dual union   
select 6,'B','广州',2 from dual union   
select 7,'B','深圳',3 from dual;  
  
  
select * from tb;  
--方法1
select product 商品,sum(type) 城市数,sum(num) 数量 from (  
  select product  ,area  ,sum(num) num,1 type from tb  
  group by product,area  
)group by product;  
--方法2
select  product 商品,count(distinct(area)) 城市数,sum(num) 数量 from tb group by product;