SQL in 24 Hours, Sams Teach Yourself, 7th Edition

Hour 12

Introduction to Database Queries

What You’ll Learn in This Hour:

• ▶   Defining a database query

• ▶   Using the SELECT statement

• ▶   Adding conditions to queries using the WHERE clause

• ▶   Using column aliases

• ▶   Selecting data from another user’s table

In this hour, you learn about database queries, which involve using the SELECT statement. The SELECT statement is the most frequently used of all SQL commands after a database is created. The SELECT statement enables you to view data that is stored in the database.

Using the SELECT Statement

The SELECT statement, which is known as the Data Query Language (DQL) command, is the basic statement used to construct database queries. A query is an inquiry into the database to extract data ...