Question

我是这个sql世界的新手。在我是一名SQL和SQL知识有限的开发人员之后简单的连接。我在为一对多关系编写sql join时遇到了问题。这是我的问题 -

例如如果我有一个VendorsList表：

id   Name         address
1    sales        Japan
2    marketing    US

以及：

的VendorContacts表

id   vendorid        vendorempname
1    1               Tom
2    1               Bill
3    2               Jessy
4    1               Rachel
5    2               Rob

现在加入后我想要的是：

vendor_id    Name     address   vendorempname
1            Sales    Japan     Tom
1            Sales    Japan     Bill
1            Sales    Japan     Rachel
2            Marketing US       Jessy
2            Marketing US       Rob

任何人都可以帮忙写这个吗？

Answer 1

这应该做的工作

Select v.vendor_id, v.name, v.address, vc.vendorempname
  from VendorContacts vc
  join VendorList v
    on v.id = vc.vendor_id
 order by vc.vendor_id

Answer 2

  SELECT b.vendor_id, a.Name, a.address, b.vendorempname
    FROM VendorList a, VendorContact b
   WHERE a.id = b.vendor_id
ORDER BY b.vendor_id;

Answer 3

请看一下：

Select vl.vendorId,vl.name,vl.address,vc.vendorempname
from vendorlist as vl
right join VendorContacts as vc
on vl.vendorId = vc.vendorId
order by vc.vendorId asc

请尝试此操作并获取您想要的数据。

Answer 4

尝试以下查询。它提供了您正在寻找的确切结果，除了代表名称的顺序..

            WITH VENDORLIST AS 
            (SELECT '1' ID,    'sales' Name,      'Japan'  address FROM DUAL
            UNION
            SELECT '2' ID,    'marketing' Name,      'US'  address FROM DUAL),
            VENDORCONTACTS AS 
            (
            SELECT '1' ID,    '1' vendorid,      'Tom'  vendorempname FROM DUAL
            UNION
            SELECT '2' ID,    '1' vendorid,      'Bill'  vendorempname FROM DUAL
            UNION
            SELECT '3' ID,    '2' vendorid,      'Jessy'  vendorempname FROM DUAL
            UNION
            SELECT '4' ID,    '1' vendorid,      'Rachel'  vendorempname FROM DUAL
            UNION
            SELECT '5' ID,    '2' vendorid,      'Rob'  vendorempname FROM DUAL

            )
            SELECT VENDORID, NAME, ADDRESS, vendorempname FROM VENDORLIST, VENDORCONTACTS
            WHERE VENDORCONTACTS.vendorid = VENDORLIST.ID
            ORDER BY VENDORID, NAME, ADDRESS, vendorempname
            ;

Oracle sql一对多加入

4 个答案: