Facebook API Question posted in
The official documentation for the Facebook APIs can be found here.

Foreign Key relationships for Facebook API models

I have some data from Facebook API and I need to store them on Azure SQL Db.
I created the models and I’m trying to set Foreign Keys to link the tables but I always have some errors.

My models:

public class FacebookDataUser
{
    [Key]
    [JsonProperty("id")]
    public string FacebookDataUserId { get; set; }
    public string name { get; set; }
    public string birthday { get; set; }
    public string email { get; set; }
    public virtual Hometown hometown { get; set; }
    public virtual Location location { get; set; }
    public virtual Events events { get; set; }
    public virtual Likes likes { get; set; }
    public virtual Age_Range age_range { get; set; }
    public string gender { get; set; }
}

public class Hometown
{
    [Key]
    [JsonProperty("id")]
    public string HometownId { get; set; }
    public string name { get; set; }

    public string FacebookDataUserId { get; set; }
    public FacebookDataUser FacebookDataUser { get; set; }
}

public class Location
{
    [Key]
    [JsonProperty("id")]
    public string LocationId { get; set; }
    public string name { get; set; }

    public string FacebookDataUserId { get; set; }
    public FacebookDataUser FacebookDataUser { get; set; }
}

public class Events
{
    [Key]
    public string EventsId { get; set; }
    public Datum[] data { get; set; }

    public string FacebookDataUserId { get; set; }
    public FacebookDataUser FacebookDataUser { get; set; }
}

public class Datum
{
    [Key]
    public string DatumId { get; set; }
    public string description { get; set; }
    public string name { get; set; }
    public DateTime start_time { get; set; }
    public string PlaceId { get; set; }
    public Place Place { get; set; }
    public int attending_count { get; set; }
    public string type { get; set; }
    public string rsvp_status { get; set; }
    public DateTime end_time { get; set; }

    public string FacebookDataUserId { get; set; }
    public FacebookDataUser FacebookDataUser { get; set; }
}

public class Place
{
    [Key]
    public string PlaceId { get; set; }
    public string name { get; set; }
    public string LocationEventId { get; set; }
    public LocationEvent location { get; set; }

    public string DatumId { get; set; }
    public Datum Datum { get; set; }
}

public class LocationEvent
{
    [Key]
    public string LocationEventId { get; set; }
    public string city { get; set; }
    public string country { get; set; }
    public float latitude { get; set; }
    public float longitude { get; set; }
    public string state { get; set; }
    public string street { get; set; }
    public string zip { get; set; }

    public string FacebookDataUserId { get; set; }
    public FacebookDataUser FacebookDataUser { get; set; }
}

public class Likes
{
    // Doesn't have ID for Likes, but I need to have a Key in all classes.
    // If I don't have, I get an exception
    [Key]
    public string LikesId { get; set; }
    public Datum1[] data { get; set; }

    public string FacebookDataUserId { get; set; }
    public FacebookDataUser FacebookDataUser { get; set; }
}

public class Datum1
{
    [Key]
    public string Datum1Id { get; set; }
    public string category { get; set; }
    public string name { get; set; }
    public int fan_count { get; set; }
    public string website { get; set; }
    public string LocationId { get; set; }
    public LocationEvent location { get; set; }
    public string[] emails { get; set; }

    public string FacebookDataUserId { get; set; }
    public FacebookDataUser FacebookDataUser { get; set; }
}


public class Age_Range
{
    // Doesn't have ID for Age_Range, but I need to have a Key in all classes.
    // If I don't have, I get an exception
    [Key]
    public string Age_RangeId { get; set; }
    public int min { get; set; }

    public string FacebookDataUserId { get; set; }
    public FacebookDataUser FacebookDataUser { get; set; }
}

I get this exception:

Unable to determine the principal end of an association between the types ‘ApiGroma.Models.Age_Range’ and ‘ApiGroma.Models.FacebookDataUser’. The principal end of this association must be explicitly configured using either the relationship fluent API or data annotations.

If I add [Required] on Age_Range, I get this exception from Facebook API:

"modelState": {
        "facebookDataUser.age_range.FacebookDataUser": [
            "The FacebookDataUser field is required."

So, I tried to fill the values of Foreign Keys “by hand” before the method Add in my [HttpPost] method.

facebookDataUser.hometown.FacebookDataUserId = facebookDataUser.FacebookDataUserId;
facebookDataUser.location.FacebookDataUserId = facebookDataUser.FacebookDataUserId;
facebookDataUser.age_range.FacebookDataUserId = facebookDataUser.FacebookDataUserId;
facebookDataUser.likes.FacebookDataUserId = facebookDataUser.FacebookDataUserId;
facebookDataUser.events.FacebookDataUserId = facebookDataUser.FacebookDataUserId;

db.FacebookDataUsers.Add(facebookDataUser);

But I keep receiving the exception.
What’s the proper way to do this?

It’s been 2 days since I began looking for a solution, reading Microsoft blogs and others, but I can’t fix this.

OBS: I am creating the database inside the context class.

Database.SetInitializer<MobileServiceContext>(new CreateDatabaseIfNotExists<MobileServiceContext>());
Tags:

2

Answers


  1. Chosen as BEST ANSWER
    0

    So, after some changes and compairing the codes, i got it working.

    public class FacebookDataUser
    {
        [Key,JsonProperty("id")]
        public string FacebookDataUserId { get; set; }
        public string name { get; set; }
        public string birthday { get; set; }
        public string email { get; set; }
        public virtual Hometown Hometown { get; set; }
        public virtual Location Location { get; set; }
        public virtual Events Events { get; set; }
        public virtual Likes Likes { get; set; }
        public virtual Age_Range Age_Range { get; set; }
        public string gender { get; set; }
    }

    public class Hometown
    {
        [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public int HometownId { get; set; }
        public string id { get; set; }
        public string name { get; set; }

    }

    public class Location
    {
        [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public int LocationId { get; set; }
        public string id { get; set; }
        public string name { get; set; }

    }

    public class Events
    {
        [Key]
        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public int EventsId { get; set; }
        [JsonProperty("data")]
        public ICollection<EventData> EventDatas { get; set; }
    }

    public class EventData
    {
        [Key]
        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public int EventDataId { get; set; }
        public string description { get; set; }
        public string name { get; set; }
        [Column(TypeName = "datetime2")]
        public DateTime start_time { get; set; }
        public virtual Place Place { get; set; }
        public int attending_count { get; set; }     
        public string type { get; set; }
        public string rsvp_status { get; set; }
        [Column(TypeName = "datetime2")]
        public DateTime end_time { get; set; }
    }

    public class Place
    {
        [Key,DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public int PlaceId { get; set; }
        public string id { get; set; }
        public string name { get; set; }
        [JsonProperty("location")]
        public virtual LocationEvent LocationEvent { get; set; }
    }

    public class LocationEvent
    {
        [Key]
        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public int LocationEventId { get; set; }
        public string city { get; set; }
        public string country { get; set; }
        public float latitude { get; set; }
        public float longitude { get; set; }
        public string state { get; set; }
        public string street { get; set; }
        public string zip { get; set; }
    }

    public class Likes
    {
        [Key]
        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public int LikesId { get; set; }
        [JsonProperty("data")]
        public virtual ICollection<LikesData> LikesData { get; set; }
    }

    public class LikesData
    {
        [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public int LikesDataId { get; set; }
        public string id { get; set; }
        public string category { get; set; }
        public string name { get; set; }
        public int fan_count { get; set; }
        public string website { get; set; }
        [JsonProperty("location")]
        public virtual LocationEvent LocationEvent { get; set; }
        [JsonProperty("emails")]
        public virtual ICollection<string> emails { get; set; }
    }

    public class Age_Range
    {
        [Key]
        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public int Age_RangeId { get; set; }
        public int min { get; set; }
    }

  2. 0

    As I mentioned in the comments you must have your users into the database before inserting data to other tables related to those users (foreign keys).
    Insert into table with foreign key

    @EDIT: as promised, here is some code. I recommend you updating your table to accept null values in public virtual Hometown hometown { get; set; } and others.

    public class FacebookDataUser
{
    public string FacebookDataUserId { get; set; } // You already have the primary key you need
    public string name { get; set; }
    public string birthday { get; set; }
    public string email { get; set; }
    public virtual Hometown hometown { get; set; }
    public virtual Location location { get; set; }
    public virtual Events events { get; set; }
    public virtual Likes likes { get; set; }
    public virtual Age_Range age_range { get; set; }
    public string gender { get; set; }

    public void InsertUser(FacebookDataUser Data, Likes MoreData)
    {
        using (SqlConnection myCon = new SqlConnection("connection_string"))
        {
            using (SqlCommand query = new SqlCommand("INSERT INTO users_table (@ID, ...) VALUES (ID, ...)", myCon))
            {
                query.Parameters.AddWithValue("@ID", Data.FacebookDataUserId);
                // add more parameters...
                try
                {
                    myCon.Open();
                    query.ExecuteNonQuery();
                }
                catch(Exception e)
                {
                    throw e;
                }
                finally
                {
                    myCon.Close();
                }
            }
            using (SqlCommand query = new SqlCommand("INSERT INTO likes_table (..., @USERID) VALUES (..., USERID)", myCon))
            {
                // add more parameters...
                query.Parameters.AddWithValue("@USERID", Data.FacebookDataUserId); // you won't get any exception related to the foreign key because this user is already in the parent table
                try
                {
                    myCon.Open();
                    query.ExecuteNonQuery();
                }
                catch (Exception e)
                {
                    throw e;
                }
                finally
                {
                    myCon.Close();
                }
            }
        }
    }
}

    I didn’t run a query to get the user ID as I mentioned because you already have it, just organizing the way you run your methods should be enough.

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