left join mysql php

left join mysql php

Left Join  display of result is quite different with the simple join.For this tutorial fill your product table with 2 rows where product_id is not in customer table custom_id as bellow.

6& 7 Records product_id is not in customer_id of table customer.Now you can run the following php scripts and find the difference with simple join.

<?php $host="localhost"; $username="root"; $password=""; $db_name="my_database"; mysql_connect("$host", "$username", "$password")or die("cannot connect"); mysql_select_db("$db_name")or die("cannot select DB"); $sql ="SELECT product.product_name, customer.customer_name FROM product     LEFT JOIN  customer ON customer.product_id=product.product_id ";      $result=mysql_query($sql); ?> <table  align="center"  bgcolor="#15475c"> <tr bgcolor="#ddeef5"> <td align="center" ><strong>Product Name</strong></td> <td align="center" "><strong>Customer Name</strong></td> </tr> <?php while($rows=mysql_fetch_array($result)){ ?> <tr bgcolor="#d0e7f1"> <td><?php echo $rows['product_name']; ?></td> <td><?php echo $rows['customer_name']; ?></td> </tr> <?php } ?> </table>

Resulting table is bellow

Product Name	Customer Name
Win 2007	Jones
Photoshop Cs5	Harfer
Ilustrator cs5	Taylor
Maya 10	Lopez
3D Max 9	Bayker
Office 2007
Nero 10

Simple join product Names are displayed with the customer name only the customer has ordered the products. Here in Left Join all Product Names are displayed without considering ordered or not. 

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