Summary

This chapter introduced the basic usage of SQL and examined how to use simple SELECT queries to extract data from tables in a relational database. Specifically, you learned about the following:

• Understanding basic SELECT syntax

• Providing aliases for columns and tables

• Calculating new rows based on existing content

• Sorting data

• Filtering data with the WHERE clause

• Combining multiple WHERE clauses

• Performing advanced WHERE clause filtering, including ranges

• Defining set membership

• Using pattern matching

• Filtering NULL values

In the next chapter you'll look at how you can use SQL to modify data in a database table. You'll see how to update existing data, add new data, and delete specific rows.