T-SQL allows us to combine records from more than one table and return them as a single result set. This is achieved through the concept of joins in SQL Server.
This opportunity is often necessary because data in relational databases are typically normalized. For example, we have employee data spread across two or more tables. The first table would be the basic customer data and called employee. The second table would be the department.
The data consistency requires the correct relationship between the customer and the department. Returning the complete data for a set of employees and their departments requires to join both tables.Read More