Could someone explain me about applications like MYOB or Quickbooks ?

Hi guys, I was wondering:

1. how applications like MYOB Accountings, and Quickbooks store the datas ? Do they even use database engine ? I mean, they make and generate their own file extensions. How to create such a database that doesn't need or doesn't depend on database engine, and could store large amount of data ?

2. Do applications like MYOB and Quickbooks store their datas in .txt format, then when the user wants to open the file, the program "IMPORT" the data automatically to the database engine which the user has ?

Sorry, if my questions are noobs! Well, I'm a noobie, what can I say ? Answers will be very appreciated, thanks a lot !

Chris

Applications like that basically use binary files in a format of there own definition. You can use the BinaryWriter and BinaryReader. You can do the same thing quite easily. Once you've settled on a format, you simply write your code such that the correct binary objects get written to or read from your file(s). Look up either of those classes in the help or on MSDN and it will give some basic information on how to use them and links to more detail. Note that you could store your data in BIN or DAT files, but if you want to create your own extension then all you have to do is code your app to recognise that extension. It is possible to have your app's setup create the file association on the target machine when installing.