MySQL LEFT JOIN Keyword

  MySQL LEFT JOIN Keyword

The LEFT JOIN keyword returns all records from the left table (table1), and the matching records (if any) from the right table (table2).

LEFT JOIN Syntax

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

Demo Database

In this tutorial we will use the well-known Northwind sample database.

Below is a selection from the “Customers” table:

Customers

And a selection from the “Orders” table:

Orders

MySQL 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;

MySQL LEFT JOIN with Group By Clause

The Left Join can also be used with the GROUP BY clause. The following statement returns customer id, customer name, qualification, price, and date using the Left Join clause with the GROUP BY clause.

Orders_1

Customers_1

SELECT customers_1.customer_id, cust_name, qualification, price, date  
FROM customers_1  
LEFT JOIN orders_1 ON customers_1.customer_id = orders_1.customer_id  
GROUP BY price;