I'm sure this example is out there somewhere in the interewebs but I can never seem to find it when I need it so if you know where this code came from please LMK so I can give proper attribution.

We will create an author model named Author.cs and I typically put these into a folder at /Models:

public class Author
{
    public int Id { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
}

We will create the interface named IAuthorRepository.cs and I typically put these into a folder named /Interfaces:

public interface IAuthorRepository
{
    Author Find(int id);
    List<Author> GetAll();
    Author Add(Author author);
    Author Update(Author author);
    void Remove(int id);
    void Save(Author author);
}

We will create the repository named AuthorRepositoryc.cs and I typically put these into a folder named /Repositories:

public class AuthorRepository : IAuthorRepository
    {
        private readonly IDbConnection _db =
            new SqlConnection(ConfigurationManager.ConnectionStrings["DefaultConnection"].ConnectionString);

        public Author Find(int id) {
            return _db.Query<Author>("SELECT * FROM Authors WHERE Id = @Id", new { id }).SingleOrDefault();
        }

        public List<Author> GetAll() {
            return _db.Query<Author>("SELECT * FROM Authors").ToList();
        }

        public Author Add(Author author) {
            author.FirstName = author.FirstName.Trim();
            author.LastName = author.LastName.Trim();

            const string sql = "INSERT INTO Authors (FirstName, LastName) VALUES (@FirstName, @LastName); " +
                               "SELECT CAST(SCOPE_IDENTITY() AS int)";
            var id = _db.Query<int>(sql, author).Single();
            author.Id = id;
            return author;
        }

        public Author Update(Author author) {
            author.FirstName = author.FirstName.Trim();
            author.LastName = author.LastName.Trim();

            const string sql = "UPDATE Authors " +
                               "SET FirstName = @FirstName, " +
                               "LastName = @LastName " +
                               "WHERE Id = @Id";
            _db.Execute(sql, author);
            return author;
        }

        public void Remove(int id) {
            var sql = ("DELETE FROM Authors Where Id = " + id + "");
            _db.Execute(sql);
        }

        public void Save(Author employee) {
            throw new NotImplementedException();
        }
    }