Q&A
| Q1: | Is using the GROUP BY clause mandatory when using the ORDER BY clause in a SELECT statement? |
| A1: | No. Using the GROUP BY clause is strictly optional, but it can be very useful when used with ORDER BY. |
| Q2: | What is a group value? |
| A2: | Take the CITY column from the EMPLOYEE_TBL. If you select the employee's name and city, and then group the output by city, all the cities that are identical are arranged together. |
| Q3: | Must a column appear in the SELECT statement to GROUP BY it? |
| A3: | Yes, a column must be in the SELECT statement to GROUP BY it. |
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