Based on the star schema example studied in chapter 6 (cf. slide13), answer the following three questions. SQL Extensions to support OLAP queries: advanced AGGREGATE functions Consider the following star schema example Question 1 Write the proper SQL query to obtain the result illustrated in the table below. Note that all of these Quantity_sold are related to the month July of 2019. Question 2 We want to replace the null values in columns "Channel.Desc" and "CO" by respectively "Internet+Catalog", and "KSA+UAE". Write the SQL query to achieve this goal. 1 Question 3 Write a SQL query to display two ranks based on SUM(Quantity_sold) in a descending order. The first one will be within the following months: "2020_11", "2020_10", "2020_9". The second rank will be within the following countries: "KSA", "UAE", and "BH". Obviously, we would like to have both ranks in the same result and query