Please answer 1,2,7,8,9 in detail

In a SELECT query, what is the difference between a WHERE clause and a HAVING clause? 2. Explain why the following command would create an error and what changes could be made to fix the emor: SELECT V_CODE SUM(P_QOH) FROM PRODUCT; 3. What type of integrity is enforced when a primary key is declared? 4. Explain why it might be more appropriate to declare an attribute that contains only digits as a character data type instead of a numeric data type. 5. What is the difference between a column constraint and a table constraint? 6. What are "referential constraint actions"? 7. Rewrite the following WHERE clause without the use of the IN special operator: WHERE V_STATE IN ('TN', 'FL', 'GA') Explain the difference between an ORDER BY clause and a GROUP BY clause. Explain why the following two commands produce different results: SELECT DISTINCT COUNT(V_ CODE) FROM PRODUCT; SELECT COUNT (DISTINCT V_CODE) FROM PRODUCT; What is the difference between the COUNT aggregate function and the SUM aggregate function? Explain why it would be preferable to use a DATE data type to store date data instead of a character data type. What is a recursive join