MySQL查询基于2列选择值

Question

I have a table with 4 columns: id, A, B, C. I need to select A based on B and C.

B is a filter and has integer values, C are the filter options, also integer.

I tried this:

SELECT a FROM table WHERE (b=1 AND c IN (5,6,7)) AND (b=2 AND c IN (9,10,11))

But that doesn't work because B can't be 1 and 2 at the same time. I tried with OR:

SELECT a FROM table WHERE (b=1 AND c IN (5,6,7)) OR (b=2 AND c IN (9,10,11))

This returns A but wrong... I need both conditions to be correct.

How can I make this query work?

Thank you!

Answer 1

Group by a and then you can check the conditions in the having clause

SELECT a 
FROM your_table 
GROUP BY a
HAVING sum(b=1 AND c IN (5,6,7)) > 0
AND sum(b=2 AND c IN (9,10,11)) > 0

Answer 2

SELECT a 
    FROM your_table 
WHERE 
    CASE 
        WHEN b=1 THEN C IN(5,6,7) 
        WHEN b=2 THEN C IN(8,9,10)
    END