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Which Transact-SQL query should you use?

Your database contains a table named Purchases. The table includes a DATETIME column named
PurchaseTime that stores the date and time each purchase is made. There is a non-clustered index on the
PurchaseTime column.
The business team wants a report that displays the total number of purchases made on the current day.
You need to write a query that will return the correct results in the most efficient manner.
Which Transact-SQL query should you use?
A. SELECT COUNT(*)
FROM Purchases
WHERE PurchaseTime = CONVERT(DATE, GETDATE())
B. SELECT COUNT(*)
FROM Purchases
WHERE PurchaseTime = GETDATE()
C. SELECT COUNT(*)
FROM Purchases
WHERE CONVERT(VARCHAR, PurchaseTime, 112) = CONVERT(VARCHAR, GETDATE(),
112)
D. SELECT COUNT(*)
FROM Purchases
WHERE PurchaseTime >= CONVERT(DATE, GETDATE())
AND PurchaseTime < DATEADD(DAY, 1, CONVERT(DATE, GETDATE())) Answer: D