Joins: Retrieving data from several tables

When you create a database, you normalize the data by placing information specific to different objects in different tables, rather than in one large table with many redundant entries. Therefore, to retrieve related data from more than one table, you perform a join operation using the SQL JOIN operator. A join operation recreates a larger table using the information from two or more tables (or views). Using different joins, you can construct a variety of these virtual tables, each suited to a particular task.

Displaying a list of tables
Sample database schema
How joins work
Explicit join conditions (the ON clause)
Cross joins
Inner and outer joins
Specialized joins
Natural joins
Key joins