Let i try to explain you some things.
In an application to connect to the database , we specify the name and version of the database . In this situation, the following may occur :
1) There is no database . This may be for example in the case of initial setting program. In this case, the application itself must create the database and all the tables in it. And further, it is already working with the newly created database.
2) Database exists, but its version is outdated. It may be the case update. For example a new version of the program need additional fields in the old tables or new tables . In this case, the application must update existing tables and create new ones if necessary.
3) There is a database and its actual version . In this case, the application successfully connects to the database and running.
As you know , the phrase " application must " tantamount to the phrase " the developer must ", ie it is our task . To handle the situations described above , we need to create a class that inherits for SQLiteOpenHelper. Call it DBHelper. This class will provide us with methods to create or update the database in case of their absence or obsolescence.
onCreate
- a method that will be called if the database to which we want to connect - does not exist(it's your case)