Rows to Columns and viceversa in SQL - sql

Question

I am very new to sql and I need a better approach for the below scenario.
Table
And I need to convert to below result.

Answer 1

You can try using unpivot. Here is the sample demo with data.
DECLARE #Table TABLE (
ID INT
,COL1 VARCHAR(3)
,COL2 VARCHAR(3)
,COL3 VARCHAR(3)
,COL4 VARCHAR(3)
)
INSERT INTO #TABLE VALUES
(1,'yes',null,'yes',null)
,(2,null,'yes',null,'yes')
,(3,null,null,'yes',null)
,(4,null,null,null,null)
,(5,null,'yes','yes',null)
,(6,null,null,null,null)
,(7,null,null,null,'yes')
SELECT id
,yes
FROM (
SELECT id
,col1
,col2
,col3
,col4
FROM #TABLE
where coalesce(col1, col2, col3, col4) is not null
) AS cp
UNPIVOT(yes FOR col IN (
col1
,col2
,col3
,col4
)) AS up
union
select id, null from #TABLE
where coalesce(col1, col2, col3, col4) is null
order by id

Answer 2

Do a UNION ALL, one select for each coln, and finally one SELECT for rows without any yes at all.
select id, 'col1' from tablename where col1 = 'yes'
union all
select id, 'col2' from tablename where col2 = 'yes'
union all
select id, 'col3' from tablename where col3 = 'yes'
union all
select id, 'col4' from tablename where col4 = 'yes'
union all
select id, cast(null as char(4)) from tablename
where 'yes' not in (coalesce(col1, 'x'),
coalesce(col2, 'x'),
coalesce(col3, 'x'),
coalesce(col4, 'x'))
If the only value is 'yes' (or NULL), then the last select can be done as
select id, cast(null as char(4)) from tablename
where coalesce(col1, col2, col3, col4) is null

Answer 3

Also, you can do it as the below.
;WITH CTE
AS
(
SELECT
B.ID,
B.yes,
B.col
FROM
(SELECT ID ,
ISNULL(COL1, '') COL1 ,
ISNULL(COL2, '') COL2,
ISNULL(COL3, '') COL3 ,
ISNULL(COL4, '') COL4
FROM #Tbl) A
UNPIVOT
(
col
FOR yes in (col1, col2, col3, col4)
) B
)
SELECT CTE.ID, CTE.yes FROM CTE
WHERE col = 'yes'
UNION ALL
SELECT DISTINCT ID, '' FROM CTE A
WHERE NOT EXISTS
(
SELECT 1 FROM CTE B WHERE
B.ID = A.ID AND
B.col = 'yes'
)
Result:
ID yes
----------- -----
1 COL1
1 COL3
2 COL2
2 COL4
3 COL3
4
5 COL2
5 COL3
6
7 COL4