T-SQL If condition inside select - sql

Question

I have a condition where there are multiple scenarios and I need to check each scenario. I need to concatenate the result if two or more cases matches.
What I thought was , using CASE statement but i am unable to concatenate multiple scenarios using CASE statement.
So what I am doing now is , using if statement . Below is the query i did:
declare #result varchar(200)
set #result=''
;with cte as
(
select * from table 1
)
if(column 1=5) set #result=#result+'case1'
if(column 2=6) set #result=#result+'case2'
if(column 3=7) set #result=#result+'case3'
if(column 4=10) set #result=#result+'case4'
select *,#result from cte
So here, i need to use Select statement right after CTE but i cannot use IF/ELSE statement in select statement . But also i cannot use the CASE Statement with variable concatenate.
So the result should be like :
id | column 1 | column 2| column 3| column 4| Result
-----------------------------------------------------
3 | 5 | 6 | 6 | 9 | case1;`case2
4 | 4 | 7 | 7 | 10 | case2
5 | 5 | 6 | 6 | 10 | case1;`case2; case4
6 | 5 | 6 | 7 | 10 | case2;case2;case3;case4
7 | 4 | 5 | 6 | 3 | No Result
Anyone could help me to complete this ?

Answer 1

You can concatenate multiple CASEs in a single SELECT:
SELECT
CASE WHEN 1=1 THEN 'Case1' ELSE '' END
+ CASE WHEN 2=2 THEN 'Case2' ELSE '' END
+ CASE ...
EDIT based on comments: If, as you say, your broken code using IF really would solve your issue, then there is no issue, since the if statements you used don't need to be in the SELECT at all. You could simply do this:
declare #result varchar(200)
set #result=''
if(1=1) set #result=#result+'case1'
if(2=2) set #result=#result+'case2'
;with cte as
(
select * from table 1
)
select *,#result from cte
EDIT based on the update to original question:
So my first solution is correct. The additional details in your question allow me to make it a little more clear. By the way you can't use a variable at all for this:
;with cte as
(
select * ,
CASE WHEN column1=5 THEN 'case1' ELSE '' END +
CASE WHEN column2=6 THEN 'case2' ELSE '' END +
CASE WHEN column3=7 THEN 'case3' ELSE '' END +
CASE WHEN column4=10 THEN 'case4' ELSE '' END AS result
from table 1
)
select *,
CASE WHEN result='' THEN 'No Result Found' ELSE result END as result
from cte
Note that if you need to separate the values with semi-colons (as shown in your question) you can put a semi-colon before each value (example ';case3'), and in the final SELECT, use STUFF() to remove the first semi-colon.

Answer 2

;WITH cte AS
(
SELECT * FROM table1
)
SELECT *,(
CASE
WHEN Column1 <> 5 AND Column2 <> 6 AND Column3 <> 7 AND Column4 <> 10 THEN 'No Result'
ELSE
CASE WHEN Column1 = 5 THEN 'Case 1;' ELSE '' END +
CASE WHEN Column2 = 6 THEN 'Case 2;' ELSE '' END +
CASE WHEN Column3 = 7 THEN 'Case 3;' ELSE '' END +
CASE WHEN Column4 = 10 THEN 'Case 4;' ELSE '' END
END
)Result
FROM cte
| id | Column1 | Column2 | Column3 | Column4 | Result |
|----|---------|---------|---------|---------|------------------------------|
| 3 | 5 | 6 | 6 | 9 | Case 1;Case 2; |
| 4 | 4 | 7 | 7 | 10 | Case 3;Case 4; |
| 5 | 5 | 6 | 6 | 10 | Case 1;Case 2;Case 4; |
| 6 | 5 | 6 | 7 | 10 | Case 1;Case 2;Case 3;Case 4; |
| 7 | 4 | 5 | 6 | 9 | No Result |
Check SQL Fiddle