title: Save and load sql database to and from file
body: <p>I am writing C# application to manage passwords. For now, my database is <code>.txt</code> file, but I want to create few ways to store it. Is <code>.mdf</code> file a good way to do it?
  I know how to manage sql database in <code>.mdf</code> file, but I have no idea how to Save As to location chosen by user or How to load it again to program.</p>
  
  <p>Ofcourse it can be any different file type. I look for most secure way to do it. In future I will create asp.net application and Xamarin android application to manage this on few platforms.</p>
  
  <p>@Edit
  I will try to explain this one more time. Check this:</p>
  
  <p>User execute program. There are option to create new database or load existing.
  In creation mode user can set type of database. Now i've got only one and it's txt.
  I am wondering about other, f.e. .mdf, but I didnt know how to save .mdf file in location selected by user. Any other suggestions about possible extensions and how to secure it are appreciated.</p>
  
  <p>I want to store it as following:</p>
  
  <p>Login | Password | linkForWebsite|</p>
  
  <p>Ofcourse i will hash everything, so if any1 open .txt file, he wont see anything.</p>
  
  <p>Suggestions for hashing this string (not md5. it must be 2 way) also welcome.</p>