Wrong quantities showing in BO for products with combinations

[oskarna]

I noticed out that Prestashop is calculating wrong quantities in a certain case for products with quantities. After several tests I have found out how is it happening.

This issue is quite problematic for shops, that decided to control their quantities by prestashop's BO, instead of inventory managemenet software etc. I know this type of software COULD help, but this is Prestashop bug that should be fixed anyway.

How to achieve it?

Simple description

1. Create combinations for product.
2. Customer makes order.
3. Delete combinations from product.
4. Create again combinations for product.
5. Order cancelled.
6. Overall quantity showed in BO products list is calculated wrong.

Detailed description

1.) We have product XYZ with size combinations:
S, M, L, XL.
in database inside table pr_stock_available they have id_product_attribute:
120, 121, 122, 123

2.) Customer is making order for 5 pieces of M size.

3.) Now we are deleting size M from product XYZ only. We are deleting it because we need to make it not appear, because for e.g. this size for product XYZ it is temporary not avaible for some reason.

4.) We are adding size M back to our product XYZ (we decided to put it in offer again).
If we take a look in database now - id_product_attribute for new "size M" have different ID than before. So we have again sizes:
S, M, L, XL,
but in database their IDs are:
120, 4117, 122, 123.

5.) Our customer from pt. 2 is returning product (5 pieces). We are changing order status for cancelled - quantity is returned back to combination with ID 121.

Now we can make another look in database.
Combination with ID 121 is recreated back and now for our product XYZ we have 5 combinations:
120, 121, 122, 123, 4117
Our old "size M" combination have id 121 with quantity that is equal 5.

Now in BO we can edit combinations of our product like this:
size S = quantity 0
size M = quantity 0
size L = quantity 0
size XL = quantity 0

In moment that we hit "save" button, prestashop is calculating overall quantity (that is show in BO products list):
0+0+0+0+5= 5 pieces
but in backoffice we can clearly see in combinations tab that they are set for 0.

We can set product for "simple product" and set quantity to "0". Unfortunately after we generate combinations - after we hit "save" button - quantity is calculated wrong way again.

Half-solutions?

Half-solutions that we have tried are listed below. But in cases A and B it is hard to precisely determine when we have to fix our product. It may be a while before we find it out.

A.) You can manually change quantity of invisible combination in database.
This soultion is not acceptable for shop that have dozens of orders per day.

B.) We could create custom "cancelled" status for orders, that is not returning quantites back. Sadly it is not good solution for shop with huge amount of orders.

C.) We could (in front) hide combinations that have quantity 0 and never delete them in BO. It will not work for shops that are using option for products on request:
Availability preferences -> Behavior when out of stock -> Allow orders

info

PrestaShop version: tested at 1.7.5, 1.7.4.4, 1.7.4.2, 1.7.3.1
PHP version: 7.0.32, 7.2.11

[khouloudbelguith]

Hi @oskarna,

Thanks for your report.
Yes, I have the same behavior after following your steps.
After canceling the order, in the Product list page, we have a different quantity


Which is normal behavior.
I think the solution is the worst solution you are making because combinations are incrementally created.
So when you create a new combination, a new id will be created.

About this solution:

We could (in front) hide combinations that have quantity 0 and never delete them in BO

I think, it is the best solution to ovoid your problem.

It will not work for shops

Yes, you are right, we are aware of this issue, it is added to our debug roadmap.
It is reported in this ticket: #9667
Thanks to check & feedback.

[ghost]

I came here with a similar problem and I see that something is wrong with the quantity of products (stocks) in Prestashop when quantities are decreased manualy instead of automatic (via orders).

I have weird problem with store that was updated successfuly from 1.7.3.3 to 1.7.4.2 and 1.7.5.1.
Upgrades was always flawless (database is consistent) but some day customer says that disabled products (sold one) get back to live with available quantities... WTF...

Also i found that product quantity in BO product list show 2 (1 quantity per two sizes) but Stocks are emptied... HOW? It's very unpleasant issue ;/

Looks like somewhere quantities are added +1. Is there a way to get rid of it?

[ghost]

@oskarna try to not decrease quantities manualy but make an order from the front (like regular customer). One of my friend use Prestashop as PoS system. When something is sold in local store then his employee use his customer account to make an order.

[oskarna]

@PrestaShark
As I described in my post - this value is in database, but it is not visible in backoffice.

Check table "pr_stock_available". Sort products by ID and You will see combination with quantity larger than zero. You can edit it and problem will be solved.

[khouloudbelguith]

@oskarna, can I close the issue? it is a duplicate of #9667?
Is it? it is the only solution that exists.
THanks!

[oskarna]

It is different situation, @khouloudbelguith

[khouloudbelguith]

@oskarna,

I have the same behavior described by @oskarna.
After canceling the order, in the Product list page, we have a different quantity

In fact when we delete the combination with id_product_attribute = 201 
In the table ps_stock_available the column where id_product_attribute = 201 is deleted.
But when we cancel the order, this column is recreated in the table ps_stock_available

Before the suppression of the combination

After the suppression of the combination

After canceling the order

@marionf, what do you think?
Thanks!

[neich78]

Have a similar problem. Products with 4 combinations and different stock in each one. Stock does not match quantity shown in Catalog summary.
Please check product ID=3. Stock in combinations 103, but stock in summary = 335.

Prestashop 1.7.6.4

[jonpontet]

This is "still" outstanding right ?

Be great to get this "minor" bug that has large ramifications for so many ...fixed !

I see a lot of chatter but very little movement :(

[masiorama]

Experiencing the same issue on 1.7.7.4.

[masiorama]

In my case the issue is related to the cancellation of 2 product combinations with still 2 and 3 stocks, which led to a total of 5 available even if the "published" combinations were 0 (non available). I fixed the numbers on database and it was sorted for my specific case, but I guess that some sort of check on the stock quantity should be taken in consideration when a combination erase has been triggered.

[ocio87]

Hello,

I present the same problem. Removing a combination does not remove the stock, nor does it remove the id_product_attribute.

https://drive.google.com/file/d/11RBnPRE92TnHw7Akqxyc-lk5jX6nKFZ0/view?usp=sharing

Php 7.4
Prestashop 1.7.8.2

[Mauro207]

I have the same problem on version 1.7.8.5. The quantities shown in the product list are incorrect.

Where the total quantities between the combinations equals 1, I am shown 2 in the BO

Repeated error in other products. Can I somehow fix it or am I waiting for a new update?

[webstartconsulting]

We are the same problem at version 1.7.8.7 Not fixed yet? Any update?

[sketchypl]

any update? bump topic, i've the same problem

[MatShir]

For this issue, why not to hide unavailable combination ? 🤔
The feature is available on the Product Setting "Display unavailable attributes on the product sheet".

[kpodemski]

@MatShir also, probably to be validated on the new product list in 8.1

[MatShir]

Still present on the new product page. We have a workaround (we can hide the attribute out of stocks) for the FO until someone make a contribution on this issue

[KodeToad]

This issue is still present in PS 8.1.1.

My analysis suggests that the rows in ps_stock_available are not being removed for combinations when the parent product is not removed also.
My experience is that after creating new combinations and removing old combinations for a product without removing the product, the old rows in this table remain with the quantities they had when they were removed with BO. These are then incorrectly added to the total quantity on the summary list pages.
It could be that this table was relying on cascade delete which is not functioning in this case.
The delete function in classes/Combination.php returns false if the parent::delete function is false without removing the relevant lines.

I can find affected lines with this sql:
select * from ps_stock_available psa WHERE psa.id_product_attribute <> 0 and NOT EXISTS (select pa.id_product_attribute from ps_product_attribute pa where psa.id_product = pa.id_product and pa.id_product_attribute = psa.id_product_attribute);

I'd like to know if just removing the offending lines in ps_stock_available will be enough or are there other rows which need to be tidied up as well? It looks as if ps_stock_available records where id_product_attribute = 0 need to be updated too.

[dmarczewski]

Has anyone found a solution to this problem yet?