IF Condition in an SQL query

Question

I\'m a newbie to SQL Server. Please help me to write the following Logic in a query.

If getnow() > today 4 PM
Then
    SELECT *
    FROM table
    WHERE M         


        

Answer 1

IF datepart(hh, getdate()) >= 16
    BEGIN
        SELECT *
        FROM table
        WHERE DateDiff(day, getdate(), MailDate) = 1
    END
ELSE
    BEGIN
        SELECT *
        FROM table
        WHERE DateDiff(day, getdate(), MailDate) = 0
    END