商品表1:table1(id,name,price)
商品表2:table(id,name,price)
需求是找出表一和表二中的最贵的5件商品,并显示在页面中,该怎么做,求指教啊!
查出来后返回值是什么类型啊?
因为一会是表一的数据类型,一会是表二的数据类型啊?
Select id, name, price
From (
Select * From table1
Union
Select * From table2
)
Order By price Desc
Where rownum <= 5
性能改进是:
Select id, name, price
From (
Select * From table1 Order By price Desc Where rownum <= 5
Union
Select * From table2 Order By price Desc Where rownum <= 5
)
Order By price Desc
Where rownum <= 5