प्रश्न के लिए:get a list of customers who bought both A and B
SELECT CustomerID
FROM CustomerList
WHERE ProductID IN ('A', 'B')
GROUP BY CustomerID
HAVING COUNT(*) = 2
अगर यूनिकनेस को ProductID पर लागू नहीं किया गया था प्रत्येक CustomerID . के लिए , DISTINCT कीवर्ड आवश्यक है,
SELECT CustomerID
FROM CustomerList
WHERE ProductID IN ('A', 'B')
GROUP BY CustomerID
HAVING COUNT(DISTINCT ProductID ) = 2
दूसरे प्रश्न के लिए, "..A और C और D लेकिन B और E और F नहीं"
SELECT CustomerID
FROM CustomerList
WHERE ProductID IN ('A', 'C', 'D')
GROUP BY CustomerID
HAVING COUNT(*) = 3 AND
CustomerID NOT IN
(
SELECT CustomerID
FROM CustomerList
WHERE ProductID IN ('B','E','F')
)