SQL Server 2016: Turn multiple lines into columns with the different iterations - sql

Question

I have a table that has many InsuranceNo's for unique MemberIDs. If there are more than one InsuranceNo, I want the InsuranceNo's to shift to a column, so in the end there is one line per MemberID, with all the iterations of that ID's InsuranceNo's as a Column.
MemberID InsuranceNo
--------------------------
123456 dser
124571 jklh
123456 abcd
I want it to look like this:
MemberID InsuranceNo1 InsuranceNo2
-----------------------------------------------------
123456 dser abcd
124571 jklh
Thank you!

Answer 1

Yet another option... Just change "YourTable" to your actual table name.
Example
Declare #SQL varchar(max) = '
Select *
From (
Select MemberID
,Item = concat(''InsuranceNo'',row_number() over (Partition By MemberID Order By (Select NULL)))
,Value = InsuranceNo
From YourTable
) A
Pivot (max([Value]) For [Item] in (' + Stuff((Select ','+QuoteName(concat('InsuranceNo',ColNr))
From (Select Distinct ColNr=row_number() over (Partition By MemberID Order By (Select NULL)) from YourTable ) A
For XML Path('')),1,1,'') + ') ) p'
--Print #SQL
Exec(#SQL);
Returns
MemberID InsuranceNo1 InsuranceNo2
123456 dser abcd
124571 jklh NULL
If it helps wrap your head around PIVOT, the SQL Generated looks like this:
Select *
From (
Select MemberID
,Item = concat('InsuranceNo',row_number() over (Partition By MemberID Order By (Select NULL)))
,Value = InsuranceNo
From YourTable
) A
Pivot (max([Value]) For [Item] in ([InsuranceNo1],[InsuranceNo2]) ) p

Answer 2

I prefer a dynamic cross tab to the dynamic pivot. I find the syntax far less obtuse and it is super easy if you need to add additional columns. Here is I would go about tackling this. Of course in your case you don't need a temp table because you have an actual table to use.
if OBJECT_ID('tempdb..#Something') is not null
drop table #Something
create table #Something
(
MemberID int
, InsuranceNo varchar(10)
)
insert #Something values
(123456, 'dser')
, (124571, 'jklh')
, (123456, 'abcd')
declare #StaticPortion nvarchar(2000) =
'with OrderedResults as
(
select *, ROW_NUMBER() over(partition by MemberID order by InsuranceNo) as RowNum
from #Something
)
select MemberID';
declare #DynamicPortion nvarchar(max) = '';
declare #FinalStaticPortion nvarchar(2000) = ' from OrderedResults Group by MemberID order by MemberID';
with E1(N) AS (select 1 from (values (1),(1),(1),(1),(1),(1),(1),(1),(1),(1))dt(n)),
E2(N) AS (SELECT 1 FROM E1 a, E1 b), --10E+2 or 100 rows
cteTally(N) AS
(
SELECT ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) FROM E2
)
select #DynamicPortion = #DynamicPortion +
', MAX(Case when RowNum = ' + CAST(N as varchar(6)) + ' then InsuranceNo end) as InsuranceNo' + CAST(N as varchar(6)) + CHAR(10)
from cteTally t
where t.N <=
(
select top 1 Count(*)
from #Something
group by MemberID
order by COUNT(*) desc
)
select #StaticPortion + #DynamicPortion + #FinalStaticPortion
declare #SqlToExecute nvarchar(max) = #StaticPortion + #DynamicPortion + #FinalStaticPortion;
exec sp_executesql #SqlToExecute