fwrite problem

[Eljay]

Hello,

I am trying to write data to a txt file after reading from 2 database tables. I keep getting only 1 entry written to the g_file.txt. What am I missing here  ??? Still new to this, not sure if I am writing the code efficiently either  Thanks for any help!

$sql = "SELECT * FROM products_description";                                          
$result = mysql_query($sql, $connection) or trigger_error("SQL", E_USER_ERROR);
$num_rows = mysql_num_rows($result);
$sql2 = "SELECT * FROM products";                                                     
$result2 = mysql_query($sql2, $connection) or trigger_error("SQL", E_USER_ERROR);
$num_rows2 = mysql_num_rows($result2);

//heading to be written once to file
$f1 = fopen("g_file.txt", "w+");
fwrite($f1, "id\ttitle\tdescription\tprice\tlink\timage_link\n");

//loop to get data
while ($r2 = mysql_fetch_array($result2))           
{
$y4 = $r2["products_id"];
$y1 = $r2["products_model"];
$y2 = $r2["products_price"];
$y3 = $r2["products_image"];

	while ($r = mysql_fetch_array($result))            
			{
			$x1 = $r["products_name"];
			$x2 = $r["products_description"];
	 }
 }
$f2 = fopen("g_file.txt", "a+");
fwrite($f2, "$y4\t$x1\t$x2\t$y2\thttp://x.com/index.php?main_page=product_info&products_id=$y4\thttp://x.com/images/$y3\n");

fclose($f2); ///close the file
fclose($f1); ///close the file

[JonnoTheDev]

You will only get the final result written.

 

You should open the file once only. Write your header row.

Then write to the file within the loop for your database records. Then close the file after the loop.

 

You are also using 2 queries and a nested loop, bad idea. You should write 1 query and join the 2 tables. I am guessing they join via products_id

 

SELECT p.*,pd.products_name,pd.products_description FROM products p, products_description pd WHERE p.products_id=pd.products_id

 

Now your loop

//heading to be written once to file
$f1 = fopen("g_file.txt", "w+");
fwrite($f1, "id\ttitle\tdescription\tprice\tlink\timage_link\n");

//loop to get data
while ($r2 = mysql_fetch_array($result2)) {
$y4 = $r2["products_id"];
$y1 = $r2["products_model"];
$y2 = $r2["products_price"];
$y3 = $r2["products_image"];

fwrite($f1, $y4."\t".$y1."\t".$y2."\t".$y3."\n");
}
fclose($f1);

[angelcool]

Check this out:

http://www.phpfreaks.com/forums/index.php/topic,238878.msg1113369.html#msg1113369

 

NaCo

[Eljay]

Thanks Neil for your response. The solution worked great! Why was it a bad idea to use 2 queries and a nested loop?

[JonnoTheDev]

Because you should join tables on foreign keys. If for some reason there were 150 records in the products table and 151 in the description then you arent going to get the correct results. Also if you ordered one table in adifferent way to the other then the products wont match the descriptions.