ids.Add(

                    _hahahacontext

                    .hahahamodel

                    .FirstOrDefault(  　　

                        a =>                  //lambda做过滤

                        a.name == "张宏伟"

                        && a.age==

                        )

                    .id

                    .ToString()

                    );

        ids.Add((

                    from r in _hahahacontext.hahahamodel        // linq 做查询过滤

                    where (r.name == "张宏伟"&& r.age == )

                    select r.id

                    ).FirstOrDefault()

                    .ToString()

                    );  

viewModel.fields = new SelectList(

                _hahahacontext

                .hahahamodel1

                .Where(

                    a => _hahahacontext

                    .hahahamodel2

                    .Where(            //  lambda 过滤和联查都是放到一起的，容易搞乱

                        b =>

                            a.REF_ENUMID == "-5136816235353979"

                            && b.REF_ENUMID == "-5136816235353979"

                            && a.STATE == ""

                            && a.PARENT_ID == b.ID     //表关联

                            && b.SHOWVALUE != "欧洲"

                        )

                    .Any()

                    )

                .Select(a => a.SHOWVALUE)

                .ToArray()

                .Prepend("")

                .Distinct()

                .ToList()

                .OrderBy(a => a.ToString()));