CIS 515 Course Great Wisdom / tutorialrank.com CIS 515 Course Great Wisdom / tutorialrank.com | Page 22

2. Imagine that you are asked to identify the number of days that exist
between the first invoice and last invoice for each month and
complete the following:

1. Construct a query that will show the number of days that exist
between the first invoice and last invoice, for each month, for each
employee, using the DATEDIFF function. Be sure to provide the SQL
script that will carry out this function.

2. Construct a query to show the expected payment date if invoices
are due within 30 days of transaction.

3. Construct a query that will show distinct area codes of the
customers.

3. Create a plan of the necessary activities that would be required to
implement a valid database design process by including the following:

1. Steps in the conceptual design stage

2. Steps in DBMS selection stage

3. Steps in logical design stage

4. Steps in physical design stage