Turn without aggregation

Question

I am trying to rotate without aggregation , and work in a bit of wall.

Here is an example of T-SQL I'm trying to work with:

declare @optionalFields table (ParentId int, Name nvarchar(50), Value nvarchar(50));
insert into @optionalFields values (1, 'Field1', 'Foo');
insert into @optionalFields values (1, 'Field2', 'Bar');
insert into @optionalFields values (1, 'Field3', '42');
insert into @optionalFields values (2, 'Field1', 'Bar');
insert into @optionalFields values (2, 'Field2', 'Foo');
insert into @optionalFields values (2, 'Field3', '24');

declare @data table (Id int, Name nvarchar(50));
insert into @data values (1, 'Test record 1');
insert into @data values (2, 'Test record 2');

declare @joined table (Id int, Name nvarchar(50), OptionalFieldName nvarchar(50), OptionalFieldValue nvarchar(50));
insert into @joined
select 
     data.Id
    ,data.Name
    ,opt.Name
    ,opt.Value
from @data data
    inner join @optionalFields opt on data.Id = opt.ParentId

declare @cols as nvarchar(max) = 
    stuff((select distinct ',' + quotename(OptionalFieldName) from @joined for xml path(''), type).value('.', 'nvarchar(max)'), 1, 1, '');

select * into #tmp from @joined
-- just to see that it returning the expected values (it does)
select
     Id
    ,Name
    ,OptionalFieldName
    ,OptionalFieldValue
    ,row_number() over (partition by Id order by Id) RN 
from #tmp -- this is the FROM clause in the below dynamic-sql query

declare @query as nvarchar(max) = '
    select Id, Name, ' + @cols + '
    from (select Id, Name, OptionalFieldName, OptionalFieldValue, row_number() over (partition by Id order by Id) RN from #tmp) src 
    pivot (max(OptionalFieldName) for RN in (' + @cols + ')) pvt';

execute(@query);
drop table #tmp;

SSMS gives me 2 errors:

• Msg 8114, Level 16, State 1, Line 4 Error converting nvarchar to bigint data type.
• Msg 473, Level 16, State 1, Line 4 An invalid value for Field1 is provided in the PIVOT statement.

The select statement "debug" returns this:

The article (link above) seemed very promising, but I can’t get it to work. What am I doing wrong? Or is this article completely wrong, and what am I trying to do is impossible?

SO, - , " " , , - , OptionalFieldName , , OptionalFieldValue - , , , AFAIK.

Answer 1

, , row_number(). , - max min, .

, PIVOT, SQL. , :

select Id, Name, Field1, Field2, Field3
from 
(
  select
     Id
    ,Name
    ,OptionalFieldName
    ,OptionalFieldValue
  from #tmp
) d
pivot
(
  max(OptionalFieldValue)
  for OptionalFieldName in (Field1, Field2, Field3)
) piv;

. .

, SQL, :

declare @optionalFields table (ParentId int, Name nvarchar(50), Value nvarchar(50));
insert into @optionalFields values (1, 'Field1', 'Foo');
insert into @optionalFields values (1, 'Field2', 'Bar');
insert into @optionalFields values (1, 'Field3', '42');
insert into @optionalFields values (2, 'Field1', 'Bar');
insert into @optionalFields values (2, 'Field2', 'Foo');
insert into @optionalFields values (2, 'Field3', '24');

declare @data table (Id int, Name nvarchar(50));
insert into @data values (1, 'Test record 1');
insert into @data values (2, 'Test record 2');

declare @joined table (Id int, Name nvarchar(50), OptionalFieldName nvarchar(50), OptionalFieldValue nvarchar(50));
insert into @joined
select 
     data.Id
    ,data.Name
    ,opt.Name
    ,opt.Value
from @data data
    inner join @optionalFields opt on data.Id = opt.ParentId

declare @cols as nvarchar(max);
set @cols = stuff((select distinct ',' + quotename(OptionalFieldName) 
                   from @joined
                   for xml path(''), type).value('.', 'nvarchar(max)'), 1, 1, '');

select * into #tmp from @joined

DECLARE @query  AS NVARCHAR(MAX)

set @query = 'SELECT Id, Name,' + @cols + ' 
            from 
             (
                select Id
                  ,Name
                  ,OptionalFieldName
                  ,OptionalFieldValue
                from #tmp
            ) x
            pivot 
            (
                max(OptionalFieldValue)
                for OptionalFieldName in (' + @cols + ')
            ) p '

execute(@query);

. . , , , .

Answer 2

: , . @bluefeet - !

, , :

declare @optionalFields table (ParentId int, Name nvarchar(50), Value nvarchar(50));
insert into @optionalFields values (1, 'Field1', 'Foo');
insert into @optionalFields values (1, 'Field2', 'Bar');
insert into @optionalFields values (1, 'Field3', '42');
insert into @optionalFields values (2, 'Field1', 'Bar');
insert into @optionalFields values (2, 'Field2', 'Foo');
insert into @optionalFields values (2, 'Field3', '24');

declare @data table (Id int, Name nvarchar(50));
insert into @data values (1, 'Test record 1');
insert into @data values (2, 'Test record 2');


select 
     data.Id
    ,data.Name
    ,opt.Name as Name1
    ,opt.Value into #tmp
from @data data
    inner join @optionalFields opt on data.Id = opt.ParentId

declare @cols as nvarchar(max) = 
    stuff((select distinct ',' + quotename(Name1) from #tmp for xml path(''), type).value('.', 'nvarchar(max)'), 1, 1, '');

DECLARE @cols1 as nvarchar(max) = 
    stuff((select distinct +',MAX(CASE WHEN (pvt1.'+quotename(Name1) +' = ros.RN AND pvt1.id = ros.id) THEN ros.Value ELSE NULL END) as '+quotename(Name1)  from #tmp for xml path(''), type).value('.', 'nvarchar(max)'), 1, 1, '');

declare @query as nvarchar(max) = '
 ;WITH cte AS(
 SELECT * FROM #tmp
),

        ros AS (
        SELECT ROW_NUMBER() OVER (partition by Id order by Id) AS [RN],id,Value
        FROM cte),
        pvt1 AS (
    select *
    from (select Id, Name, Name1, row_number() over (partition by Id order by Id) RN 
            from cte) src 
    pivot (max(RN) for Name1 in ('+@cols+')) pvt)

    SELECT pvt1.ID,
            pvt1.Name,
            '+@cols1+'
    FROM pvt1 
    CROSS JOIN ros
    GROUP BY pvt1.ID,
            pvt1.Name'

execute(@query);
drop table #tmp

:

ID  Name            Field1  Field2  Field3
1   Test record 1   Foo     Bar     42
2   Test record 2   Bar     Foo     24

, insert into @optionalFields values (2, 'Field4', '15');, :

ID  Name            Field1  Field2  Field3  Field4
1   Test record 1   Foo     Bar     42      NULL
2   Test record 2   Bar     Foo     24      15