Get values of 2 columns as single value separated with '|' - sql

Question

DECLARE #mockup TABLE(Column1 VARCHAR(1),Column2 VARCHAR(1));
INSERT INTO #mockup VALUES('1','2'),('-','2'),('1','2'),('-','-'),('2','-'),('1','2');
SELECT ISNULL(NULLIF(Column1 + '|','-|'),'')
+ISNULL(NULLIF(Column2,'-'),'')
FROM #mockup
Above query result is as below,
1|2
2
1|2
2|
1|2
I want the result as above only except row4, where 2| should be only as 2 .
'|' should not be there at before or end of the values.

Answer 1

Simply join both fields and use REPLACE to remove |- and -|. Condition in WHERE clause avoids records where both fields are -:
select replace(replace(Column1+'|'+Column2,'-|',''),'|-','') as Result
from mockup
where coalesce(nullif(Column1,'-'),nullif(Column2,'-')) is not null
Output:
Result
1|2
2
1|2
2
1|2
See result here.

Answer 2

Use Replace function
SELECT replace(replace(replace(Column1 + '|' + Column2,'-|',''),'|-',''),'-','')
FROM #mockup
or try using CASE statement
SELECT CASE
WHEN column1 LIKE '[0-9]' AND column2 LIKE '[0-9]' THEN column1 + '|' + column1
WHEN column1 LIKE '[0-9]' AND column2 NOT LIKE '[0-9]' THEN column1
ELSE column2
END
FROM #mockup
if you want to check the - instead of numbers then
SELECT CASE
WHEN column1 NOT LIKE '-' AND column2 NOT LIKE '-' THEN column1 + '|' + column1
WHEN column1 NOT LIKE '-' AND column2 LIKE '-' THEN column1
ELSE column2
END
FROM #mockup

Answer 3

I would do this as:
select stuff( ((case when column1 not like '-' then '|' + column1 else '' end) +
(case when column2 not like '-' then '|' + column2 else '' end)
), 1, 1, '');
This is the simplest way that I've found to implement concat_ws() in SQL Server. concat_ws() is a function available in other databases, where you would just do:
select concat_ws('|',
(case when column1 not like '-' then column1 end),
(case when column2 not like '-' then column2 end)
)