On duplicate entry - update?

General
1

Hi!

I just have a quick question. Do you have any save/update method that can on duplicate entry update the fields for the already existing entry or do I need to first check if it’s available in the database already, fetch that object and then update it?

Thanks
Tobias

2

You need to know the objectId, then you can save the object which results in an update. If you do not know the objectId you would create a New object when saving, no matter if data is the same.

3

Thanks for the response!

Since one field in my table is “Unique Value” and “Indexed” as constraint it won’t create a new object for me. It throws an exception instead.

So the reason why I asked for on duplicate entry - update was to figure out if there was another way around the exception besides knowing the objectId.

But I guess then I’ll have to stick with doing first one access to check if available, if not create a new else update the old one. To bad, this requires 2 requests to the database and not only one, well well!

Thanks again for your response :slight_smile:

4

You can work around this by just creating a custom service.

Send your data to the service, check if exists, create if not, respond to client. = 1 client call.

It’s few lines of code, done in 2 minutes.

Cheers,
jens

5

Jens, could you please explain more how to update object when you know objectId?

6

Create an object with the same object id and just save it.

7

I got this exception BackendlessFault{ code: ‘IllegalArgumentException’, message: ‘null’ }

8

Post your related code please.

9 
 List<Person> listOfFriends = relationship.getFriends();
    listOfFreiends.add(newPerson);
    
    Relationship newrelationship = new Relationship();
    newrelationship.setObjectId(relationship.getObjectId());
    newrelationship.setFriends(relationship.getFriends());
    newrelationship.setPendings(relationship.getPendings());
    newrelationship.setRequests(relationship.getRequests());
   newrelationship.saveAsync(new AsyncCallback<Relationship>() {
        public void handleResponse(Relationship savedContact) {
            Log.v("USPJELI SMO", "USPJELI SMO");
        }


        @Override
        public void handleFault(BackendlessFault backendlessFault) {
            Log.v("No, it doesn't work", backendlessFault.toString());
        }
    });
}
10

Try

Backendless.Data.of(Relationship .class).save(newRelationShip,Asynccallback()....)
11

Same exception :confused:

12

Now I got ,BackendlessFault{ code: ‘36’, message: ‘Duplicate entry for column ‘user’’ }"

13

Have you tried this?

List<Person> listOfFriends = relationship.getFriends();
listOfFreiends.add(newPerson);
relationship.saveAsync(new AsyncCallback<Relationship>() {
public void handleResponse(Relationship savedContact) {
Log.v("USPJELI SMO", "USPJELI SMO");
}
@Override
public void handleFault(BackendlessFault backendlessFault) {
Log.v("No, it doesn't work", backendlessFault.toString());
}
});
}
14

Same problem :frowning:

15

Could you attach the source code for the Person and Relationship classes to this topic please?

16

Hey, there is a code. Thank you all for help!

Relationship.txt (5.77kB)

Person.txt (4.77kB)

17

Mladen,

I just tried exactly the same code you posted and it worked for me. Here’s what I have (this is using your Person and Relationship classes without any changes):

        final AsyncCallback<Relationship> saveRelationshipCallback = new AsyncCallback<Relationship>() {
            public void handleResponse(Relationship savedContact) {
                Log.v("USPJELI SMO", "USPJELI SMO");
            }
            @Override
            public void handleFault(BackendlessFault backendlessFault) {
                Log.v("No, it doesn't work", backendlessFault.toString());
            }
        };


        AsyncCallback<Relationship> getRelationshipCallback = new AsyncCallback<Relationship>() {
            @Override
            public void handleResponse(Relationship relationship) {
                Relationship newrelationship = new Relationship();
                newrelationship.setObjectId(relationship.getObjectId());
                newrelationship.setFriends(relationship.getFriends());
                newrelationship.setPendings(relationship.getPendings());
                newrelationship.setRequests(relationship.getRequests());
                newrelationship.saveAsync( saveRelationshipCallback );
            }


            @Override
            public void handleFault(BackendlessFault fault) {
                Log.e( "APP ERROR", fault.getMessage() );
            }
        };


        Backendless.Data.of( Relationship.class ).findFirst( getRelationshipCallback );

On the server-side I have the following table definitions:

Person:
http://support.backendless.com/public/attachments/ffe12596eae6829c04b8b1176d093751.png</img>

Relationship:
http://support.backendless.com/public/attachments/a4610eed270fa6f36a11c9d5d7e9f3cb.png</img>

I pre-created data in the tables using console so there is something I could work with:
Person data:
http://support.backendless.com/public/attachments/9e5b655480785631629aafe668ec703f.png</img>

Relationship data:
http://support.backendless.com/public/attachments/4fad3d1c32f128804fbefd243dd56222.png</img>

Would be glad to test it against your app - I would need your app id and Android secret key.

Regards,
Mark

a4610eed270fa6f36a11c9d5d7e9f3cb.png
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18

Hey, I have tried your code. I got relationship class but when I do

newrelationship.saveAsync( saveRelationshipCallback );

i still get this error: { code: ‘36’, message: ‘Duplicate entry for column ‘user’’ }

19

I can retrieve (load) Relationship instance of class but when I one to change it and save (update) I god this error.

Mark, how I can send you those information for test? Can you please post your email?