The CLR type System.Object isn't natively supporte

The CLR type System.Object isn’t natively supported by Npgsql or your PostgreSQL. To use it with a PostgreSQL composite you need to specify DataTypeName or to map it, please refer to the documentation.”

                dateNow = DateTimeUtil.Now();
                sql = "select title as column_name,content as table_name from ddg_article where id in @id";
                var a = new Dictionary<string, object> { };
                a["id"] = new List<int> { 5345 };
                parameters = a;

The CLR type System.Object isn’t natively supported by Npgsql or your PostgreSQL. To use it with a PostgreSQL composite you need to specify DataTypeName or to map it, please refer to the documentation.