How to write sql query to get this result - sql

Question

I had two tables as below:
request_id
update_from_id
sw_ref_number
raised_by_user_id
raised_date
1
0
1
3
2019-08-29 15:08:16.000
id
request_id
input_id
value
is_deleted
21
1
1
00001
0
22
1
2
3
0
75
2
1
00002
0
76
2
2
0
My query is:
select req.request_id,
req.sw_ref_number,
reqDet.[value] ,
reqDet.input_id
FROM SOF.tblSOFRequest req
left join SOF.tblSOFRequestDetails reqDet
on req.request_id = reqDet.request_id
where reqDet.input_id = 1
or reqDet.input_id = 2
And after that my result is:
request_id
sw_ref_number
value
input_id
1
1
00001
1
1
1
3
2
2
2
00002
1
2
2
2
I want a result as:
request_id
sw_ref_number
epi_db_no
manuf_no
1
1
00001
3
2
2
00002
Here input_id = 1 means epi_db_no and input_id = 2 means manuf_no.
How can I get this?
Thanks

Answer 1

You can do it using self-join like the following query.
SELECT req.request_id
,req.sw_ref_number
,reqDet.[value] AS epi_db_no
,reqDet2.[value] AS manuf_no
FROM SOF.tblSOFRequest req
LEFT JOIN SOF.tblSOFRequestDetails reqDet ON req.request_id = reqDet.request_id
LEFT JOIN SOF.tblSOFRequestDetails reqDet2 ON reqDet.request_id = reqDet2.request_id
AND reqDet2.input_id = 2
WHERE reqDet.input_id = 1

Answer 2

This seems like a simple pivot. I use conditional aggregation here:
SELECT req.request_id,
req.sw_ref_number,
MAX(CASE reqDet.input_id WHEN 1 THEN reqDet.[value] END) AS epi_db_no,
MAX(CASE reqDet.input_id WHEN 2 THEN reqDet.[value] END) AS manuf_no
FROM SOF.tblSOFRequest req
JOIN SOF.tblSOFRequestDetails reqDet ON req.request_id = reqDet.request_id
WHERE reqDet.input_id IN (1,2)
GROUP BY req.request_id,
req.sw_ref_number;