Question

我有表格文章：

arrtno     descr         unit   sales
  1        beer            1     10
  2        coke            1     12
  3        beer ct        12      5
  4        coke ct        12      7

和表突变

artno   mutation
  1         3  
  2         4

我需要查询啤酒的销售情况，因此它是1*10 + 12*5。那么如何从其他表中获取变异并将其添加到基本项目中。

Answer 1

试试这个

SELECT SUM(unit * sales) FROM article WHERE arrtno IN (    
    SELECT mutation from mutations WHERE artno IN (
        SELECT arrtno FROM article WHERE descr = 'beer'
    )
    UNION
    SELECT arrtno FROM article WHERE descr = 'beer'
)

Answer 2

试试这个

SELECT b1.unit * b1.sales + b2.unit*b2.sales
 FROM beer b1, beer b2, mutation
 WHERE b1.artno = mutation.artno
 AND b2.artno = mutation.mutation

在另一个表中添加文章时

2 个答案: