Patch Collection not Updating Blank Columns

[mike528]

I am working on an offline scenario in an app to be run from a tablet.  If connected, I load a collection of rows that can be updated offline and then synched to the DB once back online. 

I create a collection as;

ClearCollect(colMembers, Filter('[dbo].[Members], IsActive = true))

then when one of the rows is selected for edit, I update controls on a screen with their current value to be edited. When saving (clicking the save button) I issue a patch command.

Patch(colMembers, First(Filter(colMembers, MemberId = varSelectedMemberId)), {FirstName: txtFirstName.Text, LastModified: Now()})

I've paired this down for clarity, but the FirstName updates fine, but LastModified will only update if it previously had a value. I find this quite odd as I don't have this issue patching Azure DB tables directly, only a local in-memory collection. I checked other columns and all will update if they previously had a value, any rows where a column is blank, simply refuses to update. I have to keep all changes in this collection, that saves to local device data store using SaveData() so that I can synched once back online.

I would consider this a bug. Has anyone else run across this?  

I saw somewhere that UpdateIf might work, while it's a workaround, this is still not right.

Thanks!

[RandyHayes · Accepted solution]

@mike528 

Yes, this is a long standing bug with the Patch function with blank columns and collections.

Use the UpdateIf function.  It works 100% of the time.

I hope this is helpful for you.

[Eelman]

@RandyHayes 

That's interesting. Do you know if this is only related to Azure DBs or does it also affect SharePoint Lists? 

Reason I ask is because I have almost this exact same build design going on as @mike528 (thought he may have hacked my Environment for a moment, lol) except I'm using SharePoint so wanting to get ahead of any issues early, if possible.

[mike528]

@Eelman 

Sounds like it's a bug (Microsoft, you listening!!! 😀), UpdateIf() fixed my issue completely and an easy switch.

Thanks!

[mike528]

@RandyHayes 

UpdateIf, Works like a charm!

Thanks

[RandyHayes]

@Eelman 

Yep...SharePoint too!

I ran into it enough that I just got used to UpdateIf for everything.  And, it's an easy transition. 

[Eelman]

@RandyHayes @mike528 

Thanks for getting back to me. Looks like I will also be making the transition 🙂 

[mike528]

The good news is that it's an easy switch. Very thankful to @RandyHayes , otherwise I might have been bailing on my Offline capability design.  

[GoodPanos]

I just came across this issue too.  Wasted three hours fiddling with it.  I end up filling the column with a "-".

An example of UpdateIf would be helpful 😁

[Eelman]

@WarrenBelz 

FYI, Patching blanks discussion