SQL Update Patch with ForAll with keyed lookup

[akharns]

I have a Gallery with info that has been collected via a SQL view. The view contains the key fields for looking up the specific record in the source SQL table. I want to give the user the option of updating a field in that record. The gallery rows contain the current and new values of that field, with the new value defaulted to the current value. The user will scroll down and enter values in the New value field for the desired gallery rows. Then the user will press an Update Button above the Gallery. On Select for the Update Button, PowerApps should select the rows where new values were entered and for each one, retrieve the target row using the two key fields and update the value in that row.

I am thinking that, since I have the key values which uniquely identify the row to be updated, I don't need to use filter or lookup for specifying the update row (2nd Patch parameter). I should be able to directly link to the target record in the source table.

Source Data (record to be updated)
Table A
Key fields are Fld1 and Fld2
Field to be updated is UpdValue

Gallery named myGallery, with Rows containing
txtFld1 from a.Fld1
txtFld2 from a.Fld2
txtCurValue from a.UpdValue
txtNewValue - input value

On Select action for the Update Button
ForALL(Filter(myGallery.AllItems,txtCurValue.Text<>txtNewValue.Text),
Patch(
'A',
Fld1=txtFld1.Text && Fld2=txtFld2.Text,
{UpdValue:txtNewValue.Text})
)

[EddieE]

@akharns 

Using the Value() function was my plan B haha

You can use Refresh(yourDataSource) after the Patch to show the updated data - although when I tested this with SP my Gallery refreshed without using Refresh()

[RandyHayes]

@akharns 

So if SD_ID is part of the gallery items, then you don't need the overhead of the label and the text to value conversion.

If would become - as was mentioned by @EddieE :

Patch(A,
    ForAll(
        Filter(myGallery.AllItems, 
            txtCurValue.Text <> txtNewValue.Text &&
            Fld1 = txtFld1.Text && 
            Fld2=txtFld2.Text
        ),
        {SD_ID: SD_ID,
         UpdValue:txtNewValue.Text
        }
    )
)

As for the "refresh"...this depends on your gallery...is the Item of it based on "A", or is it based on a collection?  If it is a collection - keep in mind that a collection is an in-memory variable.  It will not update unless you update it.  This is expensive for performance if it is just the datasource - in which case, it is better to just have your gallery based on the datasource directly.

Also in terms of refreshing..."A" needs to be a table in your datasource, not a view.  Views will never refresh unless performing a performance expensive Refresh on them.  If it is a table, then it will already refresh itself.

[akharns]

@RandyHayes , that's an interesting problem to solve.  My table is very large, certainly too large to house in a collection.  I am using the SQL source table in the gallery.  I have two filters that are prepopulated but that's not enough to get a smaller list.  My objective is to allow the user to set exclusion flags on records.  They'll need to do various filters to find those records.  Unfortunately we can't use partial word searches due to delegation.  If they change the filter, it will clear the unposted flags.  I'll probably force the patch of those flags before allowing the filter to change.  To make things even more complicated, there are three hierarchy levels to manage, with interactions on the exclusion.  I'll work it out but I'm in the early stages right now.  I'm not ready to ask a specific question.  For now, I think I'll just add a button to refresh.  If they have put more filters on, that shouldn't be too bad.  There's a risk of re-updating the rows because the gallery doesn't see that it was updated already.  I can think of a few ways to manage that.  We'll see.

Anyway, thank you both for your input.  I'll have to see if there's a way to give both of you credit for the answer.  If not, sorry about that.  I appreciate your input.