Question

There is a table with 2 columns:

x    y
1    1
1    2
1    3
2    2
2    3
2    4
3    1
3    2
3    5

If I need to find all X, where Y = 5. I use query

SELECT * FROM table WHERE y = 5

But, I need to find all X, where Y = 2 AND Y = 3.

How to do this on 1 query?

In result I must to get X = 1 and 2 (NOT 3!). And Y may be many

If i use SELECT * FROM table WHERE y IN (1, 2)

I will get x = 1, 2, 3, but I not need Y = 3 because in table no line x=3, y=3

Answer 1

SELECT   x
FROM     tableName
WHERE    y IN (2,3)
GROUP BY X
HAVING COUNT(*) = 2

• SQLFiddle Demo

if unique contraint was not specified for each x, then DISTINCT is a must

SELECT   x
FROM     tableName
WHERE    y IN (2,3)
GROUP BY X
HAVING COUNT(DISTINCT y) = 2

• SQLFiddle Demo