如何将多个结果行转换为具有各自值的单行 SQL

Question

我在 SQL DB 中有两个表Users和UserAttributes 。

表具有类似的结构

需要的是

我尝试的查询

Select * from (
Select u.UserId,u.Username,u.UserEmail,ua.objectName,ua.objectValue 
from Users u join userAttribute on u.UserId=ua.UserId
where ua.objectName='city' or pv.objectName='phone')) results
PIVOT (count(UserId)
For objectName IN ([city],[phone])) As pivot_table;

电流输出

仍然是双重条目也是因为我不知道城市和电话结果是 0 和 1（布尔值）。

请帮助获得所需的输出。

Answer 1

您可以进行聚合：

select u.UserId, u.username, u.usermemail,
       max(case when ua.objectname = 'city' then objvalue end),
       max(case when ua.objectname = 'phone' then objvalue end)
from User u join 
     userAttribute ua
     on u.UserId = ua.UserId
group by u.UserId, u.username, u.usermemail;

Answer 2

您可以使用条件聚合从UserAttributes表中提取值：

SELECT u.userid, u.userName, u.userEmail,
       MAX(CASE WHEN ua.objName = 'city'  THEN ua.objValue END) AS city,
       MAX(CASE WHEN ua.objName = 'phone' THEN ua.objValue END) AS phone,
FROM Users u
JOIN UserAttributes ua ON ua.userid = u.userid
GROUP BY u.userid, u.userName, u.userEmail

Answer 3

要仅旋转两列， join很方便：

select u.*, uac.objvalue as city, uap.objvalue as phone
from users u left join
     userattributes uac
     on uac.userid = u.userid and
        uac.objname = 'city' left join
     userattributes uap
     on uap.userid = u.userid and
        uap.objname = 'phone';

如果您只需要匹配的行，请添加：

where uac.objvalue is not null or uap.objvalue is not null

如果您有更多列，那么join和group by可能是更好的方法：

select u.*, au.*
from users u join
     (select ua.userid,
             max(case when objname = 'city' then objvalue end) as city,
             max(case when objname = 'phone' then objvalue end) as phone
      from userattributes ua
      group by ua.userid
     ) ua
     on u.userid = ua.userid;

Answer 4

请尝试以下查询。 希望这会有所帮助

DECLARE @Users table(userid int, username varchar(50))
insert into @Users  select 1,'Shiv'
insert into @Users  select 2,'Ajay'

DECLARE @UserAttr table(userid int,objname varchar(100),objvalue varchar(100))
insert into @UserAttr select 1,'City','Chd'
insert into @UserAttr select 1,'phone','9646XXXX'
insert into @UserAttr select 2,'phone','8985XXXX'


select * FROM
(
select u.userid,u.username,ua.objname,ua.objvalue FROM @Users u
join  @UserAttr ua on u.userid = ua.userid
)a pivot (min(a.objvalue) FOR a.objname in ([city],[phone]))p

Answer 5

以下是您可以尝试使用或不使用枢轴的查询。

1. Without Pivot:- 

SELECT  ur.UserId,ur.UserName,ur.UserEmail,
        Max(CASE WHEN ua.objName = 'city' THEN ua.ObjValue END) as city,
       Max (CASE WHEN ua.ObjName = 'phone' THEN ua.ObjValue END) as Phone
FROM    Users ur 
        JOIN UserAttribute ua ON ur.UserId = ua.UserId

GROUP BY ur.UserId,ur.UserName,ur.UserEmail

2. With Pivot :- 

select * from (select us.UserId,us.UserName,us.UserEmail,ua.ObjName,ua.ObjValue from users us inner join UserAttribute ua on us.UserId=ua.UserId)t pivot
(
max(ObjValue)
For ObjName in ([city],[phone]) 

) as pivot_table;


Please try this query and let me know the results.