c# - Checking if an object exists in an SQL table based on a Column and some object's Field -

i trying check if there exists instance of object unique id in sql table. not place duplicates. here sample of have:

string ui = someobj.getuniqueid();  iqueryable<string> checkdataquery = cdq in db.someobjects                                            cdq.uniqueid == ui                                            select cdq.uniqueid;  if (checkdataquery != ui) // attempt @ making sure                           // query returned , not                            // string representing nothing found, if there                           // better checking method more helpful. 

the main issue running can not access checkdataquery string. attempted casting it, , using .single()/.first() methods, however, former had no success, , latter made single string being returned list of characters.

you can check result enumerable.any like:

bool ifexists = db.someobjects.any(r=> r.uniqueid == ui); 

if want object, can use firstordefault , check null like:

var dbobject = db.someobjects.firstordefault(r=> r.uniqueid == ui); if(dbobject != null) {   //record exists }