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

Hour 14

Joining Tables in Queries

What You’ll Learn in This Hour:

• ▶   Defining table joins

• ▶   Identifying the different types of joins

• ▶   Understanding how and when joins are used

• ▶   Taking a look at practical examples of table joins

• ▶   Understanding the effects of improperly joined tables

• ▶   Renaming tables in a query using an alias

To this point, all database queries you have executed in this book have extracted data from a single table. However, examples of manual joins have been shown in exercises. In a manual join, you separately select data for multiple tables to get the final result set that you want. During this hour, you learn how to join tables in a query so that you can efficiently and automatically retrieve data from multiple ...