SQL Combine multiple rows into one with multiple columns

问题

I've got multiple rows in my result from my query:

for example, the table "Address":

Street | Number | City
----------------------
A1     | A2     | A3
B1     | B2     | B3

What I actually want is:

Address1_Street | Address1_Number | Address1_City | Address2_Street | Address2_Number | Address2_City
------------------------------------------------------------------------------------------------------
A1              | A2              | A3            | B1              | B2              | B3

Anyone who knows how I can achieve this?

I've managed to get to this point now (sorry for using other columns, the one above was an example, but I'll guess you'll get the point):

select distinct
    a.ID,
    a.Name, 
    ca1.NameLine1 as Address1_NameLine1, 
    ca2.NameLine1 as Address2_NameLine1
from 
    dbo.Accounts a, 
    dbo.Addresses ca1,
    dbo.Addresses ca2
where 
        (a.ID = ca1.AccountID AND a.ID = ca2.AccountID)
    AND (a.Name = 'TEST')
    AND (ca1.ID <> ca2.ID)

But I'm still getting 2 rows... where Address1 switches with Address2. Anyone who knows how to only get one? Thanks!

回答1:

Try:

select ID,
       max(Name) Name,
       max(case when rn=1 then NameLine1 end) Address1_NameLine1,
       max(case when rn=2 then NameLine1 end) Address1_NameLine2
from
(select a.ID,
        a.Name, 
        ca.NameLine1,
        rank() over (partition by a.ID order by ca.ID) rn
 from dbo.Accounts a 
 join dbo.Addresses ca on a.ID = ca.AccountID
 where a.Name = 'TEST') sq
group by ID

回答2:

select address1.* ,address2.* from
Address address1 inner join on Address address2
on address1.userid=address2.userid

you can choose inner or left join based on data.

来源：https://stackoverflow.com/questions/15290114/sql-combine-multiple-rows-into-one-with-multiple-columns

标签

sql

sql-server

sql-server-2008-r2