自动创建数据库、自动建表、修改表结构

public class MyOpenHelper extends SQLiteOpenHelper {public MyOpenHelper(Context context) {super(context, "testdb.db", null, 1);}@Overridepublic void onCreate(SQLiteDatabase db) {db.execSQL("CREATE TABLE person (personid integer primary key autoincrement, name varchar(20), phone VARCHAR(12) NULL)");}@Overridepublic void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {db.execSQL("ALTER TABLE person ADD amount integer");}}

public void creadDb(){MyOpenHelper myhelper=new MyOpenHelper(getContext());myhelper.getWritableDatabase();}