Sqlite extension is not working as expected

Question

I am working on an WinRT app. I want to use sqlite-net-extensions to support OneToMany, ManyToMany.

using SQLiteNetExtensions.Attributes;
using SQLite;

[Table("WorkFlow")]
public class Workflow
{
    [PrimaryKey, AutoIncrement]
    public int WorkflowId { get; set; }
    public string Name { get; set; }
    public int Revision { get; set; }
    [OneToMany]
    public List<Step> Steps { get; set; }
}

[Table("Step")]
public class Step
{
    public string Type { get; set; }
    public string Description { get; set; }
    [ManyToOne]
    public Workflow Workflow { get; set; }
}

When I try to generate the tables for the database, it raises the exception:

An exception of type 'System.NotSupportedException' occurred in app_name.exe but was not handled in user code Additional information: Don't know about System.Collections.Generic.List`1 [app_name.Model.modelName]

This is coming from the SqlType in SQLite.cs.

But from the example on the sqlite-net-extensions homepage, List property should work fine.

This is a copy of their example:

public class Stock
{
    [PrimaryKey, AutoIncrement]
    public int Id { get; set; }
    [MaxLength(8)]
    public string Symbol { get; set; }

    [OneToMany]      // One to many relationship with Valuation
    public List<Valuation> Valuations { get; set; }
}

public class Valuation
{
    [PrimaryKey, AutoIncrement]
    public int Id { get; set; }

    [ForeignKey(typeof(Stock))]     // Specify the foreign key
    public int StockId { get; set; }
    public DateTime Time { get; set; }
    public decimal Price { get; set; }

    [ManyToOne]      // Many to one relationship with Stock
    public Stock Stock { get; set; }
}

Can anyone give me some suggestions to solve this problem? Thanks.

Answer 1

This is usually an installation issue caused because SQLite-Net Extensions was compiled using a SQLite-Net library but you are running your App using another. You can try adding the PCL NuGet package to your project or you can download the sources from Git and reference the project directly.

Answer 2

Try giving Table (Step) a Primary Key and a Foreign Key referencing Table (WorkFlow)

[Table("Step")]
public class Step
{
    [PrimaryKey, AutoIncrement]
    public int StepId { get; set; }
    [ForeignKey(typeof(WorkFlow))]
    public int WorkFlowId { get; set; }
    public string Type { get; set; }
    public string Description { get; set; }
    [ManyToOne]
    public Workflow Workflow { get; set; }
}