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How to load the first object from a data table using API

by on April 10, 2015

There is an API for loading the very first object created in the table. The first object is determined by the value in the created column – Backendless picks the one with the smallest timestamp. The code below demonstrating loading an object from the Person table:

The Person class used in the code below is:

    import java.util.Date;
    public class Person
    {
        public int age;
        public String name;
        public Date birthdate;
    }

    Asynchronous sample API (Android and Plain Java):

    Backendless.Data.of( Person.class ).findFirst( new AsyncCallback<Person>()
    {
        @Override
        public void handleResponse( Person firstPerson )
        {
           System.out.println( "Name - " + firstPerson.name );
           System.out.println( "Age - " + firstPerson.age );
           System.out.println( "Birthdate - " + firstPerson.birthdate );
        }
        @Override
        public void handleFault( BackendlessFault backendlessFault )
        {
           System.out.println( "Server reported an error - " + backendlessFault.getMessage() );
        }
    } );

    Synchronous sample API (Plain Java only):

    Person firstPerson = Backendless.Data.of( Person.class ).findFirst();
    System.out.println( "Name - " + firstPerson.name );
    System.out.println( "Age - " + firstPerson.age );
    System.out.println( "Birthdate - " + firstPerson.birthdate );

    @interface Person : NSObject
    
    @property(strong, nonatomic) NSString *name;
    @property(nonatomic) NSInteger age;
    @property(strong, nonatomic) NSDate *birthdate;
    
    @end

    API usage example:

    [[Backendless.shared.data of:[Person class]] findFirstWithResponseHandler:^(Person *firstPerson) {
        NSLog(@"Name - %@", firstPerson.name);
        NSLog(@"Age - %li", (long)firstPerson.age);
        NSLog(@"Birthdate - %@", firstPerson.birthdate);
    } errorHandler:^(Fault *fault) {
        NSLog(@"Error: %@", fault.message);
    }];

    @objcMembers class Person: NSObject {
        var name: String?
        var age: Int = 0
        var birthdate: Date?
    }

    API usage example:

    Backendless.shared.data.of(Person.self).findFirst(responseHandler: { firstPerson in
        if let firstPerson = firstPerson as? Person {
            print("Name - \(firstPerson.name ?? "")")
            print("Age - \(firstPerson.age)")
            print("Birthdate - \(firstPerson.birthdate)")
        }
    }, errorHandler: { fault in
        print("Error: \(fault.message ?? "")")
    })

    const Backendless = require('backendless')
    /*
     Or use `import Backendless from 'backendless'` for client side.
     If you don't use npm or yarn to install modules, you can add the following line
     <script src="//api.backendless.com/sdk/js/latest/backendless.min.js"></script>
     to your index.html file and use the global Backendless variable.
    */
    
    Backendless.initApp('YOUR_APP_ID', 'YOUR_JS_API_KEY')
    
    const onSuccess = firstPerson => {
      console.log(`Name - ${ firstPerson.name }`)
      console.log(`Age - ${ firstPerson.age }`)
      console.log(`Birthdate - ${ firstPerson.birthdate }`)
    }
    
    const onError = error => {
      console.error('Server reported an error: ', error.message)
      console.error('error code: ', error.code)
      console.error('http status: ', error.status)
    }
    
    Backendless.Data.of('Person').findFirst()
      .then(onSuccess)
      .catch(onError)

    The code produces the following output:

    Name - Spiderman
    Age - 30
    Birthdate - Tue Apr 09 18:00:00 CST 1985