Inner Join

Inner join - returns only rows that matched using key/attribute.

Join with ON clause

SELECT *
FROM table1
JOIN table2
  ON (tablee1.column_name = table2.column_name)

Creating Three-way joins with ON clause

SELECT employee_id, city, department_name
FROM employees e
JOIN departments d
  ON (e.department_id = d.department_id)
  JOIN locations l
ON (d.location_id = l.location_id)

Specified table using ON clause

SELECT [attribute1]
FROM employees e
JOIN employees m
ON (e.id = m.id)

To join other attribute in same table (recursive relationship)

To combine the table,

• n-1 JOIN statement is required to join n table(s)
  • For example : 3 table join requires 2 JOIN statement