JustLee Books has become the exclusive distributor for a number of books. The company now needs to assign sales representatives to retail bookstores to handle the new distribution duties. For these assignments, create new tables to support the following:

1. Modify the following SQL command so that the Rep_ID column is the PRIMARY KEY for the table and the default value of Y is assigned to the Comm column. (The Comm column indicates whether the sales representative earns commission.)---------20 points

CREATE TABLE store_reps

(rep_ID NUMBER(5),

last VARCHAR2(15),

first VARCHAR2(10),

comm CHAR(1));

2. Change the STORE_REPS table so that NULL values cant be entered in the name columns (First and Last).---------------------------------------------20 points

3. Change the STORE_REPS table so that only a Y or N can be entered in the Comm column. ---20 points

4. Add a column named Base_salary with a datatype of NUMBER(7,2) to the STORE_REPS table. Ensure that the amount entered is above zero. ---------20 points

5. Create a table named BOOK_STORES to include the columns listed in the following chart.-----20 points