Question

我有一张名为customer，hobby的表。顾客有几个爱好。所以，如果我和表爱好者一起加入我的桌面客户，我会得到如下结果：

[CustomerName]    [HobbyName]
Harry              Tennis
Harry              Football

我希望看到这样的结果：

[CustomerName]    [HobbyName1]    [HobbyName2]
Harry              Tennis           Football

我当前的查询如下所示：

  Select tCustomer.name, tHobby.name 
    from dbo.customer    tCustomer
    inner join dbo.hobby tHobby on tHobby.customerid = tCustomer.id

Answer 1

您没有提供有关表结构的许多详细信息，但您可以使用PIVOT获取最终结果，但为了使用它，您首先要使用row_number()为每个爱好生成一个唯一的序列每个客户：

select customer, Hobby1, Hobby2
from
(
  Select c.name customer, 
    h.name hobby,
    'Hobby'+
      cast(row_number() over(partition by c.id 
                             order by h.name) as varchar(10)) seq
  from dbo.customer c
  inner join dbo.hobby h 
    on h.customerid = c.id
) d
pivot
(
  max(hobby)
  for seq in (hobby1, Hobby2)
) piv;

见SQL Fiddle with Demo。如果您不想使用PIVOT函数，那么您还可以使用CASE表达式和聚合函数：

select customer,
  max(case when seq = 1 then hobby end) hobby1,
  max(case when seq = 2 then hobby end) hobby2
from
(
  Select c.name customer, 
    h.name hobby,
    row_number() over(partition by c.id 
                      order by h.name) seq
  from dbo.customer c
  inner join dbo.hobby h 
    on h.customerid = c.id
) d
group by customer;

请参阅SQL Fiddle with Demo

sql将行转换为sql server 2008r2中的列

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