MySQL - How can I do a conditional WHERE and OR clause Query? - mysql

Question

Problem 1:
I need to add a field in a WHERE clause with a condition in my stored procedure, so what is the right syntax for the below query in CASE condition?
Problem 2:
OR condition is giving me all records with values 0,1,2,3,4 for below condition (I need tqm.is_imp = 1 if not found then tqm.is_imp IN (0,2,3,4)). What should I do? Please help.
tqm.is_imp = 1 OR tqm.is_imp IN (0,2,3,4)
My Query:
SELECT tqm.id INTO selectedQuestionNumber
FROM tc_question_master tqm
INNER JOIN tc_question_mapping tqmap ON tqmap.tc_question_id = tqm.id
WHERE tqmap.syllabus_chapter_details_id IN (SELECT cms_id from topic where chapter_id IN (SELECT id from MyChapters))
AND tqm.marks = CurMark
CASE WHEN CurQuestionType > 0 THEN
AND tqm.question_type = CurQuestionType
END
AND (tqm.level_of_question = 'Easy' OR tqm.level_of_question
IN ('Moderate','Difficult','Very difficult'))
AND (tqm.is_imp = 1 OR tqm.is_imp IN (0,2,3,4))
AND tqm.id NOT IN (SELECT q.question_id FROM QBDetails q)
ORDER BY RAND() LIMIT 1;

Answer 1

The upper part is just a reformat, but lower as you approach the logic that was a case expression, most of that is pure guess.
SELECT
tqm.id INTO selectedQuestionNumber
FROM tc_question_master tqm
INNER JOIN tc_question_mapping tqmap ON tqmap.tc_question_id = tqm.id
WHERE tqmap.syllabus_chapter_details_id IN (
SELECT
cms_id
FROM topic
WHERE chapter_id IN (
SELECT
id
FROM MyChapters
)
)
AND (
tqm.level_of_question = 'Easy'
OR tqm.level_of_question IN ('Moderate', 'Difficult', 'Very difficult')
)
AND (
tqm.is_imp = 1
OR tqm.is_imp IN (0, 2, 3, 4)
)
AND tqm.id NOT IN (
SELECT
q.question_id
FROM QBDetails q
)
## now it is really vague
AND (
tqm.marks = CurMark
OR
(CurQuestionType > 0 AND tqm.question_type = CurQuestionType)
)
## end of guesswork
ORDER BY
RAND()
LIMIT 1;