mysql - 数据收集多个表？

Question

table 'sales'
id refid invoice itemid price
1  001   1501    ss01   12000

table 'purchase'
id itemid price
1  ss01   10200

table 'reference'
id refid refname
1  001   bedul

我的sql DB中有这三个表，所以如何使用mysql查询将它们变成单个表：

table 

id refid refname invoice itemid sellprice buyprice profit
1  001   bedul   1501    ss01   12000     10200    1800

Answer 1

您的结果表格不够详细，但您可以尝试：

class PostViewSet(viewsets.ReadOnlyModelViewSet):
    queryset = Post.objects.all()
    serializer_class = PostSerializer

Answer 2

以下内容已经过测试并确认为有效......

SELECT sales.id,
       sales.refid,
       reference.refname,
       sales.invoice,
       sales.itemid,
       sales.price AS sellprice,
       purchase.price AS buyprice,
       sales.price - purchase.price AS profit
FROM sales, purchase, reference
WHERE sales.refid = reference.refid AND
      sales.itemid = purchase.itemid;