Updating multiple records based on single ID

[EpicTriffid]

I have absolutely no idea why this isn't working.

I have a single person's ID number, and am trying to use that to update a field of all records with that same ID in the datasource.

For example: I have Joe Bloggs, whose department is currently Admin. His main record is held in my Staff Table with this current dept:

Name	Dept	UserID
Joe Bloggs	Admin	1234

I then have a sub table that lists all Joe trips in this year:

Name	Dept	UserID	Trip Destination
Joe Bloggs	Admin	1234	Paris
Joe Bloggs	Admin	1234	London
Joe Bloggs	Admin	1234	Madrid
Joe Bloggs	Admin	1234	The Moon

Now, Joe has left the Admin department, and gone to Sales. I need to update both the Department field in my Staff table, and at the same time, update all the records belonging to Joe in the Trips table to also have Sales as their department. Changing the Staff table, where I have a gallery and a patch function is fine. The sub table is the issue. When I change his department, I save the chosen department to a variable called chosenDept (in this case "Sales"). I then need to apply that same choice to all records in the Trips table. My Trips table is really quite large, so I have to filter the datasource down so delegation doesn't become an issue.

I'm using this code:

ClearCollect(recordToChange,Filter('[dbo].[Trips]', UserID = ThisItem.UserID));

ForAll(recordToChange,
Patch(Filter('[dbo].[Trips]', UserID = ThisItem.UserID),
    LookUp(
        '[dbo].[Trips]', ID = recordToChange[@ID]),
    {Department: First(chosenDept).Value}));

My Staff table updates fine, the variable reads "Sales", but the Department field in the Trips table just doesn't change at all. I'm not getting delegation errors or anything. It just does not work. Have I missed out something fundamental?

[RandyHayes · Accepted solution]

@EpicTriffid 

Consider changing your formula to the following:

UpdateIf('[dbo].[Trips]', 
         UserID=ThisItem.UserID,
         {Department: First(chosenDept).Value}
)

That should give you what you need.

I hope this is helpful for you.

[v-qiaqi-msft · Accepted solution]

Hi@EpicTriffid,

Based on the issue that you mentioned, do you want to patch all the records related to Joe based on the UserID?

Could you please share more about the scenario, please show me how you create the variable?

Most often, we use Patch() to update a single record. It isn't commonly used to update multiple records and the usage of Patch() to update multiple records looks like this:

Patch( DataSource, BaseRecordsTable, ChangeRecordTable1)

@RandyHayes  provides a correct direction that UpdateIf() formula will be more efficient in this case.

Further, I think 

I have a test on my side with your Patch(), please modify your formula as below.

ClearCollect(recordToChange,Filter('[dbo].[Trips]', UserID = ThisItem.UserID))
ClearCollect(ChangeRecordsTable, 
             UpdateIf(recordToChange,UserID = ThisItem.UserID, {Dept:"Sales"})
);
Patch('[dbo].[Trips]',recordToChange, ChangeRecordsTable)

Best Regards,

Qi