DB copy to dev server and UPdate db after updating

I would like to copy required tables to server and I will do modifications in the tables. after modification I will  Update the tables in Server. Am Making modifications in the copy of production db. Don't want to perform huge operations directly to the db as it impacts 

 

as of now I am using caching. storing table objects in caching and modifying it and updating it to database.

 

Problem with this technique is I need  latest data every time. so I have to clear and load cache again and again whenever I need to run the application (it takes time). and in dev environment, if multiple users working in same machine, one user clears cache of others while working.

 

Any ideas pls.  (asp.net sql)