Advanced Joins in SQL Server: Complex Relationships

Write a Self Join Query

Using an Employee table with ManagerID, write a query to list employees and their managers.

Expected output: A list showing each employee's name alongside their manager's name.

Hint: Alias the Employee table twice and join on ManagerID and EmployeeID.

Join Multiple Tables

Write a query joining Customers, Orders, and Products to show customer orders with product names.

Expected output: A result set with customer names, order IDs, and product names.

Hint: Use INNER JOINs and join on appropriate foreign keys.

Composite Key Join Practice

Join Orders and OrderDetails tables on OrderID and ProductID to list order quantities.

Expected output: Rows showing order IDs, product IDs, and quantities.

Hint: Include both columns in the ON clause with AND.

A self join is when a table is joined to itself to compare rows within the same table. It is used for hierarchical data, such as employee-manager relationships.

You specify all columns that make up the composite key in the join condition using AND to ensure precise matching.

Yes, SQL allows joining multiple tables by chaining join clauses, enabling complex queries across several related tables.