IGenericRepository<T> - Err The entity type Employee_Data is not part of the model for the current context ?

Question

Hi

I try to make and dll project for IGenericRepository to let me use it in any project

and i set connection string name in my project web.config to be the same as I set it in the dll

 <connectionStrings>
    <add name="MyConnection" connectionString="data source=.;initial catalog=Dr_Emplo;persist security info=True;user id=ahmedamin;password=sasa2206;MultipleActiveResultSets=True;App=EntityFramework" providerName="System.Data.SqlClient"/>
  </connectionStrings>

and when I try to get data using it from "Employee_Data" I type:

 public class HomeController : Controller
    {
        IUnitOfWork<Employee_Data> _uow;

        public HomeController()
        {
            _uow = new UnitOfWork<Employee_Data>();
        }

        public HomeController(IUnitOfWork<Employee_Data> uof) // Fake 
        {
            _uow = uof;
        }

        public ActionResult Index()
        {
            var x = _uow.TableName.FindByID(1);
            return View(x);
        }
    }

but I got err:

The entity type Employee_Data is not part of the model for the current context

I don't know why I see that error and don't know what i must do to fix it - "did I must add something in OnModelCreating because I'm using code first" ?

I do the following in my dll project:

1. create DatabaseContext class:

 class DatabaseContext : DbContext
    {
        public DatabaseContext() : base("name=MyConnection")
        {

        }
    }

2. Create IGenericRepository<T> interface:

 public interface IGenericRepository<T> where T : class
    {
        
        IQueryable<T> List(Expression<Func<T, bool>> filter = null);

        T FindByID(int id);

        void Add(T toAdd);

        void Edit(int id, T toUpdate);

        void Delete(int id);
    }

3. Create EFGenericRepository<T> class:

ublic class EFGenericRepository<T> : IGenericRepository<T> where T : class
    {
        DbContext db;
        IDbSet<T> entity;

        public EFGenericRepository(DbContext db)
        {
            this.db = db;
            this.entity = this.db.Set<T>();
        }

        public IQueryable<T> List(Expression<Func<T, bool>> filter = null)
        {
            if (filter != null)
            {
                return entity.Where(filter); 
            }
            return entity;
        }

        // Find Data
        public T FindByID(int id)
        {
            return entity.Find(id);
        }

        // Insert Data
        public void Add(T entityToAdd)
        {
            entity.Add(entityToAdd);
        }

        // Update Data
        public void Edit(int id, T entitToUpdate)
        {
            entity.Attach(entitToUpdate);
            db.Entry<T>(entitToUpdate).State = EntityState.Modified;
        }

        // Delete Data
        public void Delete(int id)
        {
            T selectedEntity = entity.Find(id);
            db.Entry<T>(selectedEntity).State = EntityState.Deleted;
        }
    }

4. Create IUnitOfWork<T> interface:

public interface IUnitOfWork<T> : IDisposable where T : class
    {
        IGenericRepository<T> TableName { get; }

        void Save();
    }

5. Create UnitOfWork<T> class:

public class UnitOfWork<T> : IUnitOfWork<T>, IDisposable where T : class
    {
        DbContext _context;

        public UnitOfWork()
        {
            _context = new DatabaseContext();
        }

        private IGenericRepository<T> _EntityName;

        public IGenericRepository<T> TableName
        {
            get
            {
                if (_EntityName == null)
                {
                    return new EFGenericRepository<T>(_context);
                }
                return _EntityName;
            }
        }

        public void Dispose()
        {
            _context.Dispose();
            GC.SuppressFinalize(this);
        }

        public void Save()
        {
            _context.SaveChanges();
        }
    }