Patch not updating one particular column in collection

[RomanKorchak]

Hi All

I have a strange issue - I have a SharePoint list which I make into collection (just one row) in my Powerapp and then updating some columns. I have 1 particular column that just would not update. I tried  

      Patch( Collection, LookUp(Collection, ProjectNo=GProjectNo), {Column1: "ggg" } )

and it just would not update but it does update any other columns.

I tried copying that SP List (need to have exactly the same columns), connecting into Powerapp and update its collection - same issue with that one column.

Column name definitely correct - I triple checked it.   

Thanks

[poweractivate · Accepted solution]

@RomanKorchak 

That's very interesting.

Even if it seems like it doesn't make sense, try using UpdateIf and use a condition that always evaluates to true.

If you do this, does it work in the case of SP list column entry that had no value?

[RomanKorchak]

@poweractivate  - Yes, UpdateIf works fine

[DeeTronSEAM]

Could it be that you're facing this known issue?

https://powerusers.microsoft.com/t5/Building-Power-Apps/Unable-to-update-collection-from-gallery-if-...

I.e. that PApps currently has a bug/issue that it cannot update a column's value if that row from the datasource came with a NULL for that column.  Note that loosely speaking, NULL is a Blank in PApps (and, yes, the definition of Blank is being changed in PApps as time goes by).

As @timl  explains in that post:

"

A workaround for this problem is to replace any blank fields with an empty string. You could use code that looks like this after your ClearCollect:

UpdateIf(collection1, IsBlank(UtilityProviderName), {UtilityProviderName:""})
--> Repeat the above for any possible blank fields that you might want to update

"