javascript - Realtime Database Records Working Design in Web Application -

i have question, how design/achieve design pattern web application in existing erp system in such way if 1 user fetches record(s) in browser editing purpose , same record being used user, how tackle changes made first user or wise versa , keep updated information both users. trying work on webapp under mvc+c#+angularjs+javascript there loading of records(say 500 nos.) on first form load, binding first record based on id form fields , when user searching record first looking buffered/loaded records if found binds record form fields otherwise goes database search , fetches there, bind fetched record form fields , appends same buffered/loaded records list(array of objects) browsers. yes, here real situation, suppose if user visits form loads 500 records on load, user waits 10 minutes without doing particular record (say id 144) , if other user visits same form , loads same no of records includes record no 144 , make changes , saves db how previous user if tries update record no 144 changed other user not updated here in his/her buffered records. how overcome issue, can advise on please.

thanks.