Pls help me to modify the query for performance improvement

Question

Hi,
I have the below initialization
DECLARE @Active bit =1 ;
Declare @id int
SELECT @Active=CASE WHEN id=@id and [Rank] ='Good' then 0 else 1 END  FROM dbo.Students
I have to change this query in such a way that the conditions id=@id and [Rank] ='Good' should go to the where condition of the query. In that case, how can i use Case statement to retrieve 1 or 0? Can you please help me to modify this initialization?

Answer 1

I dont understand your query...May be below? or provide us sample data and your output...
SELECT *  FROM dbo.students
where @Active=CASE
WHEN id=@id and rank ='Good' then 0 else 1 END
But, I doubt you will have performance improvement here?
Do you have index on id?
If you are looking for getting the data for @ID with rank ='Good' then use the below:Make sure, you have index on id,rank combination.
SELECT *  FROM dbo.students
where  id=@id
and rank ='Good'