Stored Procedure - issues with query - sql

Question

I'm simply unable to to find a solution for this stored procedure query.
I have Person and a Student table. In Person table I store a bool value isFootballPlayer and Student table has an FK PersonId that links it to the Person table.
I have a web app where there is a search functionality that includes checkbox for Student, Person, and Football Player, in order to filter the results. So when only Person is selected, it will return all which are not Players nor Students.
My stored procedure looks like this:
"SP stuff"
#IncludePerson bit,
#IncludePlayer bit,
#IncludeStudent bit
AS
BEGIN
WITH i (Id)
SELECT
p.PersonId as Id
FROM
Person p
LEFT OUTER JOIN
Student s ON s.PersonId = p.PersonId
WHERE
(s.PersonId IS NULL OR #IncludeStudent = 1) AND
(p.IsFootballPlayer = 0 OR #IncludePlayer = 1) AND
((s.PersonId > 0) OR #IncludePerson = 1)
)
SELECT i.Id
FROM i
GROUP BY i.Id
END
The issue here is that some of the students can also be football players, and so when only the student checkbox is checked, the result excludes the students that are also football players, unless both checkboxes are checked.
Can anyone help me in the right direction and give me some tip on how I can modify the stored procedure to manage to show students that are also football players, without having to check both checkboxes?
Thanks

Answer 1

"SP stuff"
#IncludePerson bit,
#IncludePlayer bit,
#IncludeStudent bit
AS
BEGIN
Declare #Sql NVARCHAR(MAX);
SET #Sql = N'SELECT DISTINCT p.PersonId as Id
FROM Person p
WHERE 1 = 1 '
-- When only Person checkbox is checked
+ CASE WHEN (#IncludePerson = 1 AND #IncludeStudent = 0 AND #IncludePlayer = 0)
THEN N' AND p.IsFootballPlayer = 0
AND NOT EXISTS (SELECT 1 FROM Student s
WHERE s.PersonId = p.PersonId)' ELSE N'' END
-- When only Student checkbox is checked
+ CASE WHEN (#IncludePerson = 0 AND #IncludeStudent = 1 AND #IncludePlayer = 0)
THEN N' AND EXISTS (SELECT 1 FROM Student s
WHERE s.PersonId = p.PersonId)' ELSE N'' END
-- When only Player checkbox is checked
+ CASE WHEN (#IncludePerson = 0 AND #IncludeStudent = 0 AND #IncludePlayer = 1)
THEN N' AND p.IsFootballPlayer = 1 ' ELSE N'' END
-- And you can add as many as combinations you want
-- Finally execute the dynamically built sql query
Exec sp_executesql #Sql
END

Answer 2

Why don't you set the variable #IncludePlayervalue = 1 inside your stored procedure when #IncludeStudent = 1 like mentioned below -
"SP stuff"
#IncludePerson bit,
#IncludePlayer bit,
#IncludeStudent bit
AS
BEGIN
if #IncludeStudent = 1
begin
set #IncludePlayer = 1
end
WITH i (Id)
SELECT
p.PersonId as Id
FROM
Person p
LEFT OUTER JOIN
Student s ON s.PersonId = p.PersonId
WHERE
(s.PersonId IS NULL OR #IncludeStudent = 1) AND
(p.IsFootballPlayer = 0 OR #IncludePlayer = 1) AND
((s.PersonId > 0) OR #IncludePerson = 1)
)
SELECT i.Id
FROM i
GROUP BY i.Id
END