Repository pattern

RepositoryPattern.cs

//Insert new record to database
public interface ICreatableRepository<T>
{
    int Create(T value);
}

//List records
public interface IListableRepository<T>
{
    IList<T> List(DataParameterDictionary dataParameters);
}

//Database Pagination list 
public interface IPageableRepository<T>
{
    IPageableResult<T> PageList(DataParameterDictionary dataParameters);
}

//Get single record from database
public interface IRetrievableRepository<T>
{
    T Retrieve(DataParameterDictionary dataParameters);
}

//Update a record
public interface IUpdatableRepository<T>
{
    int Update(T value);
}

//Delete a record
public interface IDeletableRepository
{
    int Delete(DataParameterDictionary dataParameters);
}

public interface IPageableResult<T>
{
    IList<T> Result { get; }

    int TotalRecords { get; }
}
    
public sealed class DataParameterDictionary : Dictionary<string, object>
{
    public DataParameterDictionary() : base(StringComparer.OrdinalIgnoreCase)
    {

    }
}

//Sample for using pagination interface.

public class UserModel 
{
    public string FirstName {get;set;}    
    
    public string LastName {get;set;}
}

public sealed class UserListRepository : IPageableRepository<UserModel>
{
    public IPageableResult<UserModel> PageList(DataParameterDictionary dataParameters)
    {
        var items = new List<UserModel>
        {
            new UserModel {FirstName = "Deepu", LastName = "Madhusoodanan"}
        };

        return new UserPageList(items, 1);
    }
}

public sealed class UserPageList : IPageableResult<UserModel>
{
    public IList<UserModel> Result { get; }

    public int TotalRecords { get; }

    public UserPageList(IList<UserModel> users, int totalRecords)
    {
        Result = users;

        TotalRecords = totalRecords;
    }
}

public class UserRepositoryTest
{
    public static void TestListUser()
    {
        var userListRepository = new UserListRepository();

        var result = userListRepository.PageList(default);

        var tota = userListRepository.TotalRecords;

        var users = userListRepository.Result;
    }
}