Explanation/Reference:
Explanation:
EXCEPT and INTERSECT returns distinct rows by comparing the results of two queries.
EXCEPT returns distinct rows from the left input query that aren't output by the right input query.
Column names or aliases in ORDER BY clauses must reference column names returned by the left-side query.
Example: The following query returns any distinct values from the query to the left of the EXCEPT operator that are not also found on the right query.
-- Uses AdventureWorks
SELECT CustomerKey
FROM FactInternetSales
EXCEPT
SELECT CustomerKey
FROM DimCustomer
WHERE DimCustomer.Gender = 'F'
ORDER BY CustomerKey;
--Result: 9351 Rows (Sales to customers that are not female.)
Incorrect Answers:
B: Column names or aliases in ORDER BY clauses must reference column names returned by the left-side query.
C, D: INTERSECT returns distinct rows that are output by both the left and right input queries operator.
References: https://msdn.microsoft.com/en-us/library/ms188055.aspx