Trouble with Users Table

General
1

String whereClause = “username = '” + s + “’”;
DataQueryBuilder queryBuilder = DataQueryBuilder.create();
queryBuilder.setWhereClause(whereClause);

            Backendless.Data.of("Users").find(queryBuilder, new AsyncCallback<List<Map>>() {

                @Override
                public void handleResponse(List<Map> response) {

e
Log.d(getClass().getName(),“Response:”+response.toString());// always empty
String username = response.get(0).get(“username”).toString();// crashes

                    editTextUsername.setError(username+" Unavailable", Drawable.createFromPath("@drawable/ic_custom_logo_g"));
                }

                @Override
                public void handleFault(BackendlessFault fault) {

                    //username available
                   

                }
            });

In this code fragment the response object is always empty no matter the value of string s
I have a user with username = “tester” in the Users table, but running this code with s=“tester” still returns an empty response object

2

Hi, @Nkekere_Tommy_Minimann

I believe the issue is in the where clause statement. Please, take a look at this doc - Search with the Where Clause - Backendless SDK for Android/Java API Documentation

Regards,
Marina

3

I’ve cross checked it, there seems to be no problem with my where clause

4

Does that where clause work in our REST console? If so, could you please attach a screenshot?

5

@Nkekere_Tommy_Minimann, please provide your appId

Regards,
Marina

6

APPLICATION ID = “C2AE98FF-1A1D-BF10-FF3E-64CD97C40D00”;
Where username = ‘tester’ works in the Rest console

7

Could you show a screenshot of it working please?

8

Screenshot_20210909-170215
Screenshot_20210909-170215720×1600 77.8 KB

Screenshot_20210909-170204
Screenshot_20210909-170204720×1600 184 KB

9

It looks like the quotes in the screenshot around the word tester are different than here:

10

Am using single quotes around the username like this → ‘tester’ both in code and the REST console.

11 
‘tester’

and

'tester'

are different. The second one is correct, the first one will cause problems in the code.

12

I use exactly the same quotes around productId in this code and it works fine.
Backendless.Data.of(“Master”).update(“productId = '” + productId + “’”, masterChanges, new AsyncCallback() {
@Override
public void handleResponse(Integer objectsUpdated) {

                Log.d(getClass().getName(),"Master Record updated:"+productId);
                progressBar.hide();

            }

            @Override
            public void handleFault(BackendlessFault fault) {

               
            }
        });
13

@Nkekere_Tommy_Minimann, do you get the required result when you change the code like?

  String whereClause = "username = '" + s + "'";
        DataQueryBuilder queryBuilder = DataQueryBuilder.create();
        queryBuilder.setWhereClause(whereClause);

        List<Map> result = Backendless.Data.of( "Users" ).find( queryBuilder );
        System.out.println( "Response:" + result.toString() );
        String username = result.get( 0 ).get( "username" ).toString();
        System.out.println( username );
14

No I don’t get the required result with the above code. I still get a null response object that causes the app to crash when I try to access it.

15

Right here is a blocking call, it will not run on the main UI thread and will result in the app crashing:

List<Map> result = Backendless.Data.of( "Users" ).find( queryBuilder );

In the original code snipper you posted, I’d only change this line:

String whereClause = "username = '" + s + "'";