Power Platform Community Forum Thread Details

Hi,

Wondering for any help/advice.

(I am using Canvas Apps using Patch and not a Form on a screen.)

I have this code to patch Email address and Display Names to a Sharepoint List

Sharepoint List : My Line Managers List

Column Name 1 : 'Service Line Managers Email'

Column Name 2 : 'Service Line Managers Display Name'

On my button OnSelect event i have:

Patch('My Line Managers List',Defaults('My Line Managers List'),
{

'Service Line Managers Email':cmbUserDetailsLServiceLineManager.Selected.Mail,
'Service Line Managers Display Name':cmbUserDetailsLServiceLineManager.Selected.DisplayName
}
);

It works great to add a new item with both columns data added successfully.

But with the same data i get a duplicate item.

But i want a way to check if the 'Service Line Managers Email' already exits in the Sharepoint List then i don't want to add the data again. (Basically avoiding duplicates)

I maybe could have an error message if there is already an item in the Sharepoint List, but not essential.

Please can someone suggest a solution to add the Check if the data already exists in the Sharepoint List and it it does then do not add the string values.

I did look at using Lookup - but couldn't understand how to implement it.

Ideally the correct code to achieve this to put into the fx code on my Button OnSelect event.

Thanks in advance

Categories:

Building Power Apps

You’re almost right

This happens because Patch() with Defaults() always creates a new record.

To prevent duplicates, you can check if the email already exists using LookUp() before inserting

If(
IsBlank(
LookUp(
'My Line Managers List',
'Service Line Managers Email' = cmbUserDetailsLServiceLineManager.Selected.Mail
)
),
Patch(
'My Line Managers List',
Defaults('My Line Managers List'),
{
'Service Line Managers Email': cmbUserDetailsLServiceLineManager.Selected.Mail,
'Service Line Managers Display Name': cmbUserDetailsLServiceLineManager.Selected.DisplayName
}
),
Notify("This email already exists in the list.", NotificationType.Warning)
)

This ensures that a new item is created only if the email doesn’t already exist in the list.

As a best practice, I would recommend enabling “Enforce unique values” on the Service Line Managers Email column in SharePoint. This prevents duplicates at the data source level as well, even if multiple users submit simultaneously.

Note : Be aware of case sensitivity.

Lower('Service Line Managers Email') = Lower(cmbUserDetailsLServiceLineManager.Selected.Mail)

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