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::Ben

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Registered: 14/01/2005
Posts: 1569
Location:la rochelle, France
Hello,

Here is my code
PHP Formatted Code
// Get products from database
$sql = "SELECT p.id,p.name,p.short_description,p.price,p.download,i.pi_filename
        FROM {$_TABLES['paypal_products']} AS p
        LEFT JOIN {$_TABLES['paypal_images']} AS i
        ON i.pi_pid = p.id AND i.pi_img_num = 1
        "
;


I need the same request with i.pi_img_num >=1 but I would to limit the result to 1 raw.
If i.pi_img_num = 1, it's ok stop here, or if i.pi_img_num = 2 ok stop there...

I read that I must include a subselect but do not succedd yet. Any help would be appreciated.

Thanks,

::Ben
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jmucchiello

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Registered: 29/08/2005
Posts: 985
Can you be more specific? Are you trying to get a random image from the set of images associated with each product? I'm not really understanding what you mean by "but I would to limit the result to 1 raw. " OR "If i.pi_img_num = 1, it's ok stop here, or if i.pi_img_num = 2 ok stop there".

Can you create a few "fake" table listings and explain what you want to output:

PHP Formatted Code

products:
id name ...
1  abc
2  def

images:
pi_pid  img_num      filename
1          1         abc_1
1          2         abc_2
1          3         abc_3
2          1         def_1
2          2         def_2
 


What is the output you are expecting?

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::Ben

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Registered: 14/01/2005
Posts: 1569
Location:la rochelle, France
The actual code give me each product and the associated image when pi_img_num=1.
Like this I can print a list of products with only the first image for each product.
PHP Formatted Code

products:
abc picture abc_1
def picture def_1
 


If I delete this image, then I would like my request to give me, if the image exist, the next available one for the product (pi_img_num=2). So, there is still one image per produt on the main list.

PHP Formatted Code

products:
abc picture abc_1
def picture def_2
 

Thank you for your help;

::Ben

I'm available to customise your themes or plugins for your Geeklog CMS

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Laugh

Site Admin
Admin
Registered: 27/09/2005
Posts: 1230
$sql = "SELECT p.id,p.name,p.short_description,p.price,p.download,i.pi_filename
FROM {$_TABLES['paypal_products']} AS p
LEFT JOIN {$_TABLES['paypal_images']} AS i
ON i.pi_pid = p.id AND i.pi_img_num = 1
";


I would try something like this (I believe this will work it has been a while for me with sub queries).

SELECT p.id,p.name,p.short_description,p.price,p.download,(SELECT i.pi_filename FROM {$_TABLES['paypal_images']} AS i WHERE p.id = i.pi_id ORDER BY pi_img_num LIMIT 1) pi_filename
FROM {$_TABLES['paypal_products']} AS p

This should return all items which have at least 1 image. Sub queries can reference the outer query and be located either in the select or where clause.

Search for "subquery" on the MySQL site for more information (I would have included the url but the post was flagged as SPAM).
One of the Geeklog Core Developers.

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::Ben

Forum User
Full Member
Registered: 14/01/2005
Posts: 1569
Location:la rochelle, France
I finally found the query I needed:

PHP Formatted Code
$sql = "SELECT p.id,p.name,p.short_description,p.price,p.download,i.pi_filename
        FROM {$_TABLES['paypal_products']} AS p
        LEFT JOIN {$_TABLES['paypal_images']} AS i
        ON i.pi_pid = p.id AND i.pi_img_num = (SELECT pi_img_num FROM {$_TABLES['paypal_images']} WHERE pi_img_num >= 1 AND pi_pid = p.id LIMIT 1)
        "
;
 


maybe there is several approch but this one get products from database only once with no image if there is no image available or the first one if one or more are available.

Thanks.

::Ben
I'm available to customise your themes or plugins for your Geeklog CMS

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jmucchiello

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Full Member
Registered: 29/08/2005
Posts: 985
Quote by: cordiste

I finally found the query I needed:

PHP Formatted Code
$sql = "SELECT p.id,p.name,p.short_description,p.price,p.download,i.pi_filename
        FROM {$_TABLES['paypal_products']} AS p
        LEFT JOIN {$_TABLES['paypal_images']} AS i
        ON i.pi_pid = p.id AND i.pi_img_num = (SELECT pi_img_num FROM {$_TABLES['paypal_images']} WHERE pi_img_num >= 1 AND pi_pid = p.id LIMIT 1)
        "
;
 


maybe there is several approch but this one get products from database only once with no image if there is no image available or the first one if one or more are available.

Thanks.

::Ben


If you care, that SQL will not work with MS SQL. Try:

PHP Formatted Code
$sql = "SELECT p.id,p.name,p.short_description,p.price,p.download,i.pi_filename
        FROM {$_TABLES['paypal_products']} AS p
        LEFT JOIN {$_TABLES['paypal_images']} AS i
        ON i.pi_pid = p.id AND i.pi_img_num IN (SELECT MIN(pi_img_num) FROM {$_TABLES['paypal_images']} WHERE pi_img_num >= 1 AND pi_pid = p.id)
        "
;
 


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::Ben

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Registered: 14/01/2005
Posts: 1569
Location:la rochelle, France
If you care, that SQL will not work with MS SQL

Thank you Joe for this. :chestslam:

::Ben
I'm available to customise your themes or plugins for your Geeklog CMS

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