SQL Joins Tutorial

SQL LEFT JOIN Keyword

Different Types of SQL JOINs

Here are the different types of the JOINs in SQL:

• (INNER) JOIN: Returns records that have matching values in both tables
• LEFT (OUTER) JOIN: Returns all records from the left table, and the matched records from the right table
• RIGHT (OUTER) JOIN: Returns all records from the right table, and the matched records from the left table
• FULL (OUTER) JOIN: Returns all records when there is a match in either left or right table

The LEFT JOIN keyword returns all records from the left table (table1), and the matched records from the right table (table2). The result is NULL from the right side, if there is no match.

LEFT JOIN Syntax

SELECT column_name(s)
FROM table1
LEFT JOIN table2
ON table1.column_name = table2.column_name;

SQL LEFT JOIN Example

The following SQL statement will select all customers, and any orders they might have:

Example

SELECT Customers.CustomerName, Orders.OrderID
FROM Customers
LEFT JOIN Orders ON Customers.CustomerID = Orders.CustomerID
ORDER BY Customers.CustomerName;