CODEWITHSUNDEEP
xamarinfirebase-realtime-databasexamarin.formsxamarin.android
Anand
Anand

Reputation: 1959

Xamarin.forms retrieve firebase data according to date

In my xamarin.forms app I am using firebase database for storing users information.I am trying to fetch data between certain date range.

My data model

public class Person
    {
        public string Name { get; set; }
        public int PersonId { get; set; }
        public string Address { get; set; }
        public string PhoneNumber { get; set; }
        public string EmailID { get; set; }
        public string Password { get; set; }
        public bool Status { get; set; }
        public bool IsAdmin { get; set; }
        public List<UserLocationData> userdata { get; set; }
    }

    public partial class UserLocationData
    {
        public string Latitude { get; set; }
        public string Longitude { get; set; }
        public DateTime DateTime { get; set; }
    }

From my I app I will send two dates (Start Date and End date) so that I would like to get the data which have DateTime parameter inside this range. How to write the query for that?

What I have tried

In my Firebase helper class,

 public async Task<List<Person>> GetPersonLocation(int personId,DateTime startDate,DateTime endDate)
    {       
        return (await firebase
          .Child("Persons")       
          .OrderBy("DateTime")
          .StartAt(startDate.ToString("yyyy-MM-dd hh:mm:ss tt"))
          .EndAt(endDate.ToString("yyyy-MM-dd hh:mm:ss tt"))
          .OnceAsync<Person>()).Select(item => new Person
          {
              Name = item.Object.Name,
              PersonId = item.Object.PersonId,
              PhoneNumber = item.Object.PhoneNumber,
              EmailID = item.Object.EmailID,
              Address = item.Object.Address,
              Password = item.Object.Password,
              IsAdmin = item.Object.IsAdmin,
              Status = item.Object.Status,
              userdata=item.Object.userdata

          }).ToList();

    }

I am getting exception like this :

Response: {
  "error" : "Index not defined, add \".indexOn\": \"DateTime\", for path \"/Persons\", to the rules"
}

Which is not seems right.Any help is appreciated.

Upvotes: 0

Views: 576

Answers (1)

Cherry Bu - MSFT
Cherry Bu - MSFT

Reputation: 10346

According to your description, you want to use One to Many relation in sqlite, and query data between two data, am I riht?

If yes, I suggest you can modify your data model, because your two model don't have any relations.

public  class person
{
    [PrimaryKey, AutoIncrement]
    public int Id { get; set; }
    public string Name { get; set; }

    [OneToMany(CascadeOperations  = CascadeOperation.All)]
    public virtual IEnumerable<UserLocationData> userdata { get; set; }
}

public class UserLocationData
{
    [PrimaryKey, AutoIncrement]
    public int Id { get; set; }
    public string Latitude { get; set; }    
    public DateTime DateTime { get; set; }
    [ForeignKey(typeof(person))]
    public int personid { get; set; }
}

Then you can query the data between two date like this:

var persons = await sqliteconn.Table<person>().ToListAsync();
        var locations = await sqliteconn.Table<UserLocationData>().ToListAsync();

        var query = from p in persons
                    join location in locations on p.Id equals location.personid
                    into list1
                    select new person
                    {
                        Id = p.Id,
                        Name = p.Name,
                        userdata = list1.Where(s => s.DateTime >= Convert.ToDateTime("2019-02-01") && s.DateTime <= Convert.ToDateTime("2019-03-01"))
                    };           

        var list = query.ToList();

There are same thread that you can take a look:

Xamarin forms SQLite relation

Update:

You can try to get all data from Persons Table for firebase, then see if there are some data in userdata, if yes, now you can filter data

Upvotes: 1

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