android數據庫表不存在錯誤

Question

我正在嘗試讓我的應用程序訪問我的資產文件中的現有數據庫，但似乎給我一個錯誤，並拒絕啟動，並說wordsdata表不存在。

 04-11 01:21:17.462 28154-28154/com.example.nourhamran.anothertest E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.nourhamran.anothertest, PID: 28154 java.lang.RuntimeException: Unable to start activity ComponentInfo { com.example.nourhamran.anothertest/com.example.nourhamran.anothertest.MainActivity } : android.database.sqlite.SQLiteException: no such table: wordsdata (code 1):, while compiling: Select * FROM wordsdata ################################################################# Error Code: 1 (SQLITE_ERROR) Caused By: SQL(query) error or missing database. (no such table: wordsdata (code 1):, while compiling: Select * FROM wordsdata) ################################################################# at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2927) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2988) at android.app.ActivityThread.-wrap14(ActivityThread.java) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1631) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:154) at android.app.ActivityThread.main(ActivityThread.java:6682) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1520) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1410) Caused by: android.database.sqlite.SQLiteException: no such table: wordsdata (code 1):, while compiling: Select * FROM wordsdata ################################################################# Error Code: 1 (SQLITE_ERROR) Caused By: SQL(query) error or missing database. (no such table: wordsdata (code 1):, while compiling: Select * FROM wordsdata) ################################################################# at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method) at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:1005) at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:570) at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588) at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:59) at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:37) at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:44) at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1697) at android.database.sqlite.SQLiteDatabase.rawQuery(SQLiteDatabase.java:1636) at com.example.nourhamran.anothertest.DataBaseHelper.Displaywords(MainActivity.java:470) at com.example.nourhamran.anothertest.MainActivity.onCreate(MainActivity.java:97) at android.app.Activity.performCreate(Activity.java:6942) at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1126) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2880) ... 9 more 

這是我的DataBaseHelper代碼

 class DataBaseHelper extends SQLiteOpenHelper { private static String thewords; final String LOG_TAG = "myLogs"; private static String DATABASE_PATH = null; private static final int DATABASE_VERSION = 1; private static final String DATABASE_NAME = "voiceappdb"; private static final String TABLE_NAME = "wordsdata"; private static final String KEY_ID = "_id"; public static final String Enwd = "Enwd"; public static final String Enno = "Enno"; public static final String Enyes = "Enyes"; private SQLiteDatabase mDataBase; private final Context mContext; private ArrayList<String> mylist = new ArrayList<>(); public DataBaseHelper(Context context) { super(context, DATABASE_NAME, null, 1);// 1? Its database Version if(android.os.Build.VERSION.SDK_INT >= 17){ DATABASE_PATH = context.getApplicationInfo().dataDir + "/databases/"; } else { DATABASE_PATH = context.getFilesDir() + context.getPackageName() + "/databases/"; } this.mContext = context; } public void createDataBase() throws IOException { //If the database does not exist, copy it from the assets. boolean mDataBaseExist = checkDataBase(); if(!mDataBaseExist) { this.getReadableDatabase(); // this.close(); try { //Copy the database from assests copyDataBase(); Log.e(LOG_TAG, "createDatabase database created"); } catch (IOException mIOException) { throw new RuntimeException("ErrorCopyingDatabase"); } } } //Check that the database exists here: /data/data/your package/databases/Da Name private boolean checkDataBase() { File dbFile = new File(DATABASE_PATH + DATABASE_NAME); Log.v("dbFile", dbFile + " "+ dbFile.exists()); return dbFile.exists(); } //Copy the database from assets private void copyDataBase() throws IOException { InputStream mInput = mContext.getAssets().open(DATABASE_NAME); String outFileName = DATABASE_PATH + DATABASE_NAME; OutputStream mOutput = new FileOutputStream(outFileName); byte[] mBuffer = new byte[1024]; int mLength; while ((mLength = mInput.read(mBuffer))>0) { mOutput.write(mBuffer, 0, mLength); } mOutput.flush(); mOutput.close(); mInput.close(); } //Open the database, so we can query it public boolean openDataBase() throws SQLException { String mPath = DATABASE_PATH + DATABASE_NAME; Log.v("mPath", mPath); mDataBase = SQLiteDatabase.openDatabase(mPath, null, SQLiteDatabase.CREATE_IF_NECESSARY); //mDataBase = SQLiteDatabase.openDatabase(mPath, null, SQLiteDatabase.NO_LOCALIZED_COLLATORS); return mDataBase != null; } public word fetchwords(int id) throws SQLException { SQLiteDatabase db = this.getReadableDatabase(); Cursor mCursor = db.query(TABLE_NAME, new String[] { KEY_ID, Enwd, Enyes,Enno},KEY_ID + "=?",new String[] {String.valueOf(id)},null,null,null,null); if (mCursor != null) mCursor.moveToFirst(); word wrd = new word(Integer.parseInt(mCursor.getString(0)),mCursor.getString(1),Integer.parseInt(mCursor.getString(2)),Integer.parseInt(mCursor.getString(3))); return wrd; } public List<word> Displaywords() { List<word> wordlist = new ArrayList<word>(); String query = "Select * FROM " + TABLE_NAME; SQLiteDatabase db = this.getWritableDatabase(); Cursor cursor = db.rawQuery(query,null); if (cursor.moveToFirst()) do { word wrd = new word(); wrd.setid(Integer.parseInt(cursor.getString(0))); wrd.setword(cursor.getString(1)); wrd.setno(Integer.parseInt(cursor.getString(2))); wrd.setyes(Integer.parseInt(cursor.getString(3))); wordlist.add(wrd); } while (cursor.moveToNext()); return wordlist; } @Override public void onCreate(SQLiteDatabase db) { } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { } } 

這是我主要活動的一小段，我嘗試打開並使用數據庫

  public void onCreate(Bundle savedInstanceState) { //call superclass super.onCreate(savedInstanceState); //set contect view setContentView(R.layout.activity_main); //reference to speak button Button speechBtn = (Button) findViewById(R.id.speech_btn); wordList = (ListView) findViewById(R.id.word_list); Button sugbtn = (Button) findViewById(R.id.sug_btn); DataBaseHelper myDbHelper = new DataBaseHelper(this.getApplicationContext()); try { myDbHelper.createDataBase(); } catch (IOException e) { e.printStackTrace(); } myDbHelper.openDataBase(); List<word> words = myDbHelper.Displaywords(); for(word wordz : words){ String log = "id: " + wordz.getid() + "Enwd: "+ wordz.getword(); Log.d(" words database: ", log); } //database is open! 

所以這又是我的DataBaseHelper，帶有SQliteAssetHelper擴展

 class DataBaseHelper extends SQLiteAssetHelper { private static String thewords; final String LOG_TAG = "myLogs"; private static String DATABASE_PATH = null; private static final int DATABASE_VERSION = 1; private static final String DATABASE_NAME = "voiceappdb.db"; private static final String TABLE_NAME = "wordsdata"; private static final String KEY_ID = "_id"; public static final String Enwd = "Enwd"; public static final String Enno = "Enno"; public static final String Enyes = "Enyes"; private SQLiteDatabase mDataBase; private final Context mContext; private ArrayList<String> mylist = new ArrayList<>(); public DataBaseHelper(Context context) { super(context, DATABASE_NAME, context.getExternalFilesDir(null).getAbsolutePath(),null, 1);// 1? Its database Version if(android.os.Build.VERSION.SDK_INT >= 17){ DATABASE_PATH = context.getApplicationInfo().dataDir + "/databases/"; } else { DATABASE_PATH = context.getFilesDir() + context.getPackageName() + "/databases/"; } this.mContext = context; } public void createDataBase() throws IOException { //If the database does not exist, copy it from the assets. boolean mDataBaseExist = checkDataBase(); if(!mDataBaseExist) { this.getReadableDatabase(); // this.close(); try { //Copy the database from assests copyDataBase(); Log.e(LOG_TAG, "createDatabase database created"); } catch (IOException mIOException) { throw new RuntimeException("ErrorCopyingDatabase"); } } } //Check that the database exists here: /data/data/your package/databases/Da Name private boolean checkDataBase() { File dbFile = new File(DATABASE_PATH + DATABASE_NAME); Log.v("dbFile", dbFile + " "+ dbFile.exists()); return dbFile.exists(); } //Copy the database from assets private void copyDataBase() throws IOException { InputStream mInput = mContext.getAssets().open(DATABASE_NAME); String outFileName = DATABASE_PATH + DATABASE_NAME; OutputStream mOutput = new FileOutputStream(outFileName); byte[] mBuffer = new byte[1024]; int mLength; while ((mLength = mInput.read(mBuffer))>0) { mOutput.write(mBuffer, 0, mLength); } mOutput.flush(); mOutput.close(); mInput.close(); } //Open the database, so we can query it public boolean openDataBase() throws SQLException { String mPath = DATABASE_PATH + DATABASE_NAME; Log.v("mPath", mPath); mDataBase = SQLiteDatabase.openDatabase(mPath, null, SQLiteDatabase.CREATE_IF_NECESSARY); //mDataBase = SQLiteDatabase.openDatabase(mPath, null, SQLiteDatabase.NO_LOCALIZED_COLLATORS); return mDataBase != null; } public word fetchwords(int id) throws SQLException { SQLiteDatabase db = this.getReadableDatabase(); Cursor mCursor = db.query(TABLE_NAME, new String[] { KEY_ID, Enwd, Enyes,Enno},KEY_ID + "=?",new String[] {String.valueOf(id)},null,null,null,null); if (mCursor != null) mCursor.moveToFirst(); word wrd = new word(Integer.parseInt(mCursor.getString(0)),mCursor.getString(1),Integer.parseInt(mCursor.getString(2)),Integer.parseInt(mCursor.getString(3))); return wrd; } public List<word> Displaywords() { List<word> wordlist = new ArrayList<word>(); String query = "Select * FROM " + TABLE_NAME; SQLiteDatabase db = this.getReadableDatabase(); Cursor cursor = db.rawQuery(query,null); if (cursor.moveToFirst()) do { word wrd = new word(); wrd.setid(Integer.parseInt(cursor.getString(0))); wrd.setword(cursor.getString(1)); wrd.setno(Integer.parseInt(cursor.getString(2))); wrd.setyes(Integer.parseInt(cursor.getString(3))); wordlist.add(wrd); } while (cursor.moveToNext()); return wordlist; } 

也按要求，這是數據庫文件https://1drv.ms/u/s!AlLFl3esRRfSgW8qoNS5qcs7t_i8

Answer 1

我建議使用android-sqlite-asset-helper

Android助手類，用於使用應用程序的原始資產文件管理數據庫創建和版本管理

它使使用預裝的SQL變得異常容易。