我在 android 应用程序中使用外部数据库，它在所有模拟器和三星真实设备上运行良好。但是当我在 Acer 智能手机上查看时，我的应用程序会崩溃，并出现以下异常：
android.database.sqlite.SQLiteException: no such table:
这对我来说很奇怪。我在文件资源管理器中的数据文件夹下检查了我的数据库和所有表所在的位置。
我不明白为什么会这样。
请指导我。提前致谢
sql helper类的代码如下：
public class MyDatabaseHelper extends SQLiteOpenHelper {
// System path of application database.
private static String DB_PATH = MyApplication.getAppContext()
.getFilesDir().getParentFile().getPath()
+ "/databases/";
private static String DB_NAME = "myDB";
private SQLiteDatabase myDataBase;
private final Context myContext;
/**
* Constructor Takes and keeps a reference of the passed context in order to
* access to the application assets and resources.
*
* @param context
*/
public MyDatabaseHelper(Context context) {
super(context, DB_NAME, null, 1);
this.myContext = context;
}
/**
* Creates a empty database on the system and rewrites it with own database.
*
*/
public void createDataBase() throws IOException {
checkDataBase();
// Creates empty database default system path
this.getReadableDatabase();
try {
copyDataBase();
} catch (IOException e) {
throw new Error("Error copying database");
}
}
/**
* Checks if the database already exist to avoid re-copying the file each
* time whenever the application opened.
*
* @return true if it exists, false if it doesn't
*/
private boolean checkDataBase() {
SQLiteDatabase checkDB = null;
try {
String myPath = DB_PATH + DB_NAME;
checkDB = SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READONLY);
} catch (SQLiteException e) {
e.printStackTrace();
}
if (checkDB != null) {
checkDB.close();
}
return checkDB != null ? true : false;
}
/**
* Copies database from local assets-folder to the just created empty
* database in the system folder and from where it can be accessed and
* handled using byte stream transferring.
*
*/
private void copyDataBase() throws IOException {
// Open local db as the input stream
InputStream myInput = myContext.getAssets().open(DB_NAME + ".db");
// Path of the just created empty db
String outFileName = DB_PATH + DB_NAME;
// Open the empty db as the output stream
OutputStream myOutput = new FileOutputStream(outFileName);
// transfer bytes from the input file to the output file
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer)) > 0) {
myOutput.write(buffer, 0, length);
}
// Close the streams
myOutput.flush();
myOutput.close();
myInput.close();
}
public SQLiteDatabase openDataBase() throws SQLException {
// Opens the database
String myPath = DB_PATH + DB_NAME;
return SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READONLY);
}
@Override
public synchronized void close() {
if (myDataBase != null)
myDataBase.close();
super.close();
}
@Override
public void onCreate(SQLiteDatabase arg0) {
// TODO Auto-generated method stub
}
@Override
public void onUpgrade(SQLiteDatabase arg0, int arg1, int arg2) {
// TODO Auto-generated method stub
}
}