GenericTypeHandler.cs

 public class GenericTypeHandler<T> : SqlMapper.TypeHandler<T>
 {
     public override T Parse(object value)
     {
         return JsonConvert.DeserializeObject<T>(value.ToString());
     }

     public override void SetValue(IDbDataParameter parameter, T value)
     {
         parameter.Value = JsonConvert.SerializeObject(value);
     }
 }