Patch

[StewG]

Hello,
I have built an app to process orders placed in our department. It is supported by SharePoint Lists with 2 key lists holding all the data.
'Purchase Order Master' SharePoint list holds all the key overview information about the order including the 'TotalCost' of the order. (All the items added together).
There is also an Items SharePoint list which holds all the information for each individual item that makes up the order including its 'TotalPrice'.
These are displayed as Galleries in the app and are linked by their ID number.

I have already built in an EditForm where I can amend the 'TotalPrice' of an existing item in the Items Gallery and it will use Patch to update the 'TotalCost' in the Master Gallery. This all works fine and as expected.

Edit Item - EditForm_2

OnSuccess

Patch(
'Purchase Order Master',
MasterGallery_2.Selected,
{TotalCost: Value(TotalPriceChange_2.Text)}
);

As a development I have created a New Item Form (Form4) where I can add in a new item to the existing Order.
I am able to add the New Items 'TotalPrice' to the Master Gallerys 'TotalCost' and show the correct number.
Using the formula below

MasterGallery_2.Selected.'Total Cost' + NewTotalPrice

The issue I am having is I can not get it to update the Master List with the updated 'TotalCost' as it would with the 'EditForm'. I am using a similar formula but it resets the Master Lists 'TotalCost' to 0 (zero) every time.

New Item - Form4

OnSuccess

Patch(
'Purchase Order Master',
MasterGallery_2.Selected,
{TotalCost: Value(TotalPriceChange_4.Text)}
);

I have been working on this for a few days now and can not get my head round why it is not working. Any help would be great.

Thank you.

[SeanHenderson]

I've moved this to the Building Power Apps forum, as it's not related to Dataverse.