Multiple-Table Joins

📋 Source Datasets (4 Sample Records)

1. INNER JOIN

Definition: Returns rows only when there is a matching value in both tables.

SELECT e.name, p.project_name 
FROM employees e 
INNER JOIN projects p 
ON e.project_id = p.project_id;

2. LEFT JOIN

Definition: Returns all rows from left table, and matching rows from right table with NULLs for misses.

SELECT e.name, p.project_name 
FROM employees e 
LEFT JOIN projects p 
ON e.project_id = p.project_id;

3. RIGHT JOIN

Definition: Returns all rows from right table, and matching values from the left table.

SELECT e.name, p.project_name 
FROM employees e 
RIGHT JOIN projects p 
ON e.project_id = p.project_id;

4. CROSS JOIN

Definition: Produces a complete Cartesian product grid pairing every single item from both tables.

SELECT e.name, p.project_name 
FROM employees e 
CROSS JOIN projects p;