1. Create a view called INVOICE_View based on four columns in the INVOICE table.

2. Using your view INVOICE_View, enter a query to display values for three of the four columns included in the view.
20. Create a view named INV_VIEW_QUERY that does not allow an invoice DESCRIPTION to be changed through the view.

3. Create a sequence to be used with the primary key column of the INVOICE table. The sequence should start at 1000 and have a maximum value of 2000. Have your sequence increment by a single number. Name the sequence INVOICE_SEQ.

4. Write a script to insert a row into the INVOICE table. Be sure to use the sequence that you created for the primary key column. Create a customized prompt to enter the DESCRIPTION.

5. Create a synonym for the INVOICE table.

6. Write a query to display the three columns of data for all employees with the same MANAGER_ID as Grant.

7.Create a query to display the employee number, last name and hire date for all employees who have a salary greater than the average salary. Sort the results in descending order of salary.

8. Create a report containing the employee name, address, city, and each employee's salary. Label the columns with a different name than the column name. Break on the individual department numbers.