SQL：複数のレコードからの条件を満たすレコードを取得します

質問の場合：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

ProductIDに一意性が適用されなかった場合 すべてのCustomerID 、DISTINCT キーワードが必要です、

SELECT  CustomerID
FROM    CustomerList
WHERE   ProductID IN ('A', 'B')
GROUP   BY CustomerID
HAVING  COUNT(DISTINCT ProductID ) = 2

• SQLFiddleデモ（両方のクエリ ）

2番目の質問については、 ".. AとCとDですが、BとEとFはありません"

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')
        )

• SQLFiddleデモ