• An introduction to the table joins
• The different types of joins
• How and when joins are used
• Numerous practical examples of table joins
• The effects of improperly joined tables
• Renaming tables in a query using an alias
To this point, all database queries you have executed have extracted data from a single table. During this hour, you learn how to join tables in a query so you can retrieve data from multiple tables.
Having the capability to select data from multiple tables is one of SQL’s most powerful features. Without this capability, the entire relational database concept would not be feasible. Single-table queries are sometimes ...