How to convert table columns to rows [duplicate] - sql-server

Question

This question already has answers here:
Convert Rows to columns using 'Pivot' in SQL Server
(9 answers)
Closed 6 years ago.
I have a table like below:
+-----------+------------+--------+
| Col1 | Col2 | Col3 |
+-----------+------------+--------+
| 12345678 | FirstName | John |
| 12345678 | LastName | Smith |
| 987456321 | LastName | Clancy |
| 987456321 | MiddleName | T |
| 987456321 | Height | 176cm |
| 654125878 | FirstName | Tan |
| 654125878 | Weight | 150lb |
+-----------+------------+--------+
How to convert that to:
+-----------+-----------+------------+----------+--------+--------+
| ID | FirstName | MiddleName | LastName | Height | Weight |
+-----------+-----------+------------+----------+--------+--------+
| 12345678 | John | null | Smith | null | null |
| 987456321 | null | T | Clancy | 176cm | null |
| 654125878 | Tan | null | null | null | 150lb |
+-----------+-----------+------------+----------+--------+--------+

Answer 1

I think a conditional aggregation would do the trick here.
Assuming you don't need dynamic
Select ID = Col1
,FirstName = max(case when Col2='FirstName' then Col3 else null end)
,MiddleName = max(case when Col2='MiddleName ' then Col3 else null end)
,LastName = max(case when Col2='LastName ' then Col3 else null end)
,Height = max(case when Col2='Height' then Col3 else null end)
,Weight = max(case when Col2='Weight' then Col3 else null end)
From YourTable
Group By Col1
If you need dynamic
Declare #SQL varchar(max) = Stuff((Select Distinct ',' + QuoteName([Col2]) From Yourtable Order by 1 For XML Path('')),1,1,'')
Select #SQL = '
Select [Col1] as ID ,' + #SQL + '
From YourTable
Pivot (max(Col3) For [Col2] in (' + #SQL + ') ) p'
Exec(#SQL);
If it helps, the generated SQL for the dynamic Pivot is as follows:
Select [Col1] as ID ,[FirstName],[Height],[LastName],[MiddleName],[Weight]
From YourTable
Pivot (max(Col3) For [Col2] in ([FirstName],[Height],[LastName],[MiddleName],[Weight]) ) p