【发布时间】:2014-06-05 06:47:50
【问题描述】:
这是我下面给出的代码:
public class DBHelper extends SQLiteOpenHelper {
private static final String DBNAME = "acc_db.db";
private static final int VERSION = 4;
private static DBHelper dbHelper = null;
private static SQLiteDatabase db = null;
private DBHelper(Context context) {
super(context, DBNAME, null, VERSION);
// storing the object of this class to dbHelper
dbHelper = this;
}
@Override
public void onCreate(SQLiteDatabase database) {
DBTable.onCreate(database);
}
// Method is called during an upgrade of the database,
// e.g. if you increase the database version
@Override
public void onUpgrade(SQLiteDatabase database, int oldVersion,
int newVersion) {
DBTable.onUpgrade(database, oldVersion, newVersion);
}
public static DBHelper getInstance(Context context) {
if (dbHelper == null) {
dbHelper = new DBHelper(context);
openConnecion();
}
return dbHelper;
}
// will be called only once when singleton is created
private static void openConnecion() {
if (db == null) {
db = dbHelper.getWritableDatabase();
}
}
public synchronized void closeConnecion() {
if (dbHelper != null) {
dbHelper.close();
db.close();
dbHelper = null;
db = null;
}
}
}
在哪里找到 acc_db.db。 我将搜索 File Explorer=>data/data 但在数据文件夹下找不到数据子文件夹。 [N.B] 我使用这个数据库成功地进行了 CRUD 操作。 请帮助我。
【问题讨论】: