( )方法可以获取对SQLite数据只读的数据库对象。
A.
getReadableDataBase() in SQLiteOpenHelper
B.
getWritableDatabase() in SQLiteOpenHelper
C.
openDatabase(“testdemo”, null, SQLiteDatabase.OPEN_READWRITE) in SQLiteDatabase
D.
onUpgrade(SQLiteDatabase db,int oldVersion,int newVersion)