How to Combine Table Rows Using SQL JOIN

SQL Joins: Main Tips

• SQL joins are used to combine more than one tables rows.
• SQL INNER JOIN is the most common JOIN. An SQL INNER JOIN returns all multiple tables rows where the join condition is met.

SQL Join: Types

• LEFT JOIN: It returns the left table rows and right table rows which matched.
• RIGHT JOIN: It returns the right table rows, and left table rows which matched.
• INNER JOIN: It returns all rows when there is the same record in BOTH tables.
• FULL OUTER JOIN: It returns all rows when the same record occurs in BOTH tables.

Demo Database

This is a demo example from the "Orders" table in the database:

This is a demo example from the "Developers" table in the database:

INNER JOIN: Example

SELECT Customer_orders.ID, Developers.Name
FROM Customer_orders
INNER JOIN Developers ON Customer_orders.employee_id = Developers.ID;

The result table looks like this: