Abstract

About This Material

This is a Hands-on Tutorial from the GTN which is usable either for individual self-study, or as a teaching material in a classroom.

Questions this will address

• How can I calculate sums, averages, and other summary values?
• How can I combine data from multiple tables?
• How should I format data in a database, and why?
• How can I create, modify, and delete tables and data?
• How can I access databases from programs written in Python?

Learning Objectives

• Define aggregation and give examples of its use.
• Write queries that compute aggregated values.
• Trace the execution of a query that performs aggregation.
• Explain how missing data is handled during aggregation.
• Explain the operation of a query that joins two tables.
• Explain how to restrict the output of a query containing a join to only include meaningful combinations of values.
• Write queries that join tables on equal keys.
• Explain what primary and foreign keys are, and why they are useful.
• Explain what an atomic value is.
• Distinguish between atomic and non-atomic values.
• Explain why every value in a database should be atomic.
• Explain what a primary key is and why every record should have one.
• Identify primary keys in database tables.
• Explain why database entries should not contain redundant information.
• Identify redundant information in databases.
• Write statements that create tables.
• Write statements to insert, modify, and delete records.
• Write short programs that execute SQL queries.
• Trace the execution of a program that contains an SQL query.
• Explain why most database applications are written in a general-purpose language rather than in SQL.