Java 如何在Android中使用AsyncTask复制数据库

我想在我的应用程序中使用

AsyncTask

复制数据库。应用程序有4个片段，任何片段都显示数据库中的一个表（数据库有4个表）。但当我运行应用程序时，它会显示以下错误：

03-07 12:49:18.775 11190-11190/com.tellfa.dastanak E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.tellfa.dastanak, PID: 11190
android.database.sqlite.SQLiteException: no such table: tbl_Book (code 1): , while compiling: SELECT * FROM tbl_Book WHERE Cat_ID = ?
at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:897)
at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:508)
at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:726)
at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
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:1426)
at android.database.sqlite.SQLiteDatabase.rawQuery(SQLiteDatabase.java:1365)
at com.tellfa.dastanak.Database.DataBase.getCat1_Datas(DataBase.java:157)
at com.tellfa.dastanak.Fragments.Home_Frag.onCreateView(Home_Frag.java:49)
at android.support.v4.app.Fragment.performCreateView(Fragment.java:1962)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1067)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1248)
at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:738)
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1613)
at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:570)
at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:141)
at android.support.v4.view.ViewPager.populate(ViewPager.java:1106)
at android.support.v4.view.ViewPager.populate(ViewPager.java:952)
at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1474)
at android.view.View.measure(View.java:17496)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5466)
at android.support.design.widget.CoordinatorLayout.onMeasureChild(CoordinatorLayout.java:610)
at android.support.design.widget.CoordinatorLayout.onMeasure(CoordinatorLayout.java:677)
at android.view.View.measure(View.java:17496)
at android.support.v4.widget.DrawerLayout.onMeasure(DrawerLayout.java:940)
at android.view.View.measure(View.java:17496)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5466)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:430)
at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:135)
at android.view.View.measure(View.java:17496)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5466)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1438)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:724)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:615)
at android.view.View.measure(View.java:17496)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5466)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:430)
at android.view.View.measure(View.java:17496)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5466)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1438)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:724)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:615)
at android.view.View.measure(View.java:17496)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5466)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:430)
at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2636)
at android.view.View.measure(View.java:17496)
at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2031)
at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1193)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1400)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1078)
at android.view.Vi

public class DataBase extends SQLiteOpenHelper {

    private static String DB_PATH = "";
    private static String DB_NAME = "Dastansara";
    private static int DB_VERSION = 1;
    private SQLiteDatabase sqLiteDatabase;
    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 DataBase(Context context) {
        super(context, DB_NAME, null, DB_VERSION);

        if (android.os.Build.VERSION.SDK_INT >= 17) {
            DB_PATH = context.getApplicationInfo().dataDir + "/databases/";
        } else {
            DB_PATH = "/data/data/" + context.getPackageName() + "/databases/";
        }

        this.myContext = context;
    }

    @Override
    public void onCreate(SQLiteDatabase db) {

    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    }

    /**
     * Creates a empty database on the system and rewrites it with your own database.
     */
    public void createDataBase() throws IOException {

        boolean dbExist = checkDataBase();
        if (dbExist) {
            // do nothing - database alerdy exist
        } else {

            this.getReadableDatabase();

            try {
                copyDataBase();
            } catch (IOException e) {
                throw new Error("Error copying database");
            }
        }
    }

    /**
     * Check if the database already exist to avoid re-copying the file each time you open the application.
     *
     * @return true if it exists, false if it doesn't
     */
    public boolean checkDataBase() {

        SQLiteDatabase checkDB = null;
        try {
            String myPATH = DB_PATH + DB_NAME;
            checkDB = SQLiteDatabase.openDatabase(myPATH, null, SQLiteDatabase.OPEN_READONLY);

        } catch (SQLiteException e) {
            /// database does't exist yet
        }

        if (checkDB != null) {
            checkDB.close();
        }
        return checkDB != null ? true : false;
    }

    /**
     * Open DataBase
     *
     * @throws SQLException
     */
    public void openDataBase() throws SQLException {

        String myPATH = DB_PATH + DB_NAME;
        sqLiteDatabase = SQLiteDatabase.openDatabase(myPATH, null, SQLiteDatabase.OPEN_READONLY);
    }

    /**
     * Close DataBase
     */
    public void closeDataBase() {

        sqLiteDatabase.close();
    }

    /**
     * Copies your database from your local assets-folder to the just created empty database in the
     * system folder, from where it can be accessed and handled.
     * This is done by transfering bytestream.
     */
    public void copyDataBase() throws IOException {

        //Open your local db as the input stream
        InputStream myInput = myContext.getAssets().open(DB_NAME);
        // Path to the just created empty db
        String myPath = DB_PATH + DB_NAME;
        //Open the empty db as the output stream
        OutputStream myOutput = new FileOutputStream(myPath);

        byte[] buffer = new byte[1024];
        int length;
        //transfer bytes from the inputfile to the outputfile
        while ((length = myInput.read(buffer)) > 0) {
            myOutput.write(buffer, 0, length);
        }
        //Close the streams
        myOutput.flush();
        myOutput.close();
        myInput.close();
    }

    @Override
    public synchronized void close() {
        if (sqLiteDatabase != null) {
            sqLiteDatabase.close();
        }
        super.close();
    }

    public Cursor getCat1_Datas(SQLiteDatabase sqLiteDatabase) {

        try {
            String query = "SELECT * FROM tbl_Book WHERE Cat_ID = ?";

            Cursor cursor = sqLiteDatabase.rawQuery(query, new String[] {"1"});

            if (cursor != null) {
                cursor.moveToNext();
            }
            return cursor;
        } catch (SQLException e) {
            Log.e("Data Adapter", "getTestData >>" + e.toString());
            throw e;
        }
    }
}

public class Home_Frag extends Fragment {

    DataProvider dataProvider;
    DataBase dataBase;
    SQLiteDatabase sqLiteDatabase;
    Cursor cursor;
    ListView listView;
    Cat1_frag_adapter cat1FragAdapter;
    private LoadDB_AsyncTask task;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.frag_home,
                container, false);

        task = new LoadDB_AsyncTask(getContext());
        task.execute();

        dataBase = new DataBase(getActivity());
        sqLiteDatabase = dataBase.getReadableDatabase();
        cursor = dataBase.getCat1_Datas(sqLiteDatabase);

        listView = (ListView) rootView.findViewById(R.id.list);
        cat1FragAdapter = new Cat1_frag_adapter(getActivity(), R.layout.list_card_layout);
        listView.setAdapter(cat1FragAdapter);

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            listView.setNestedScrollingEnabled(true);
        }

        if (cursor.moveToFirst()) {
            do {
                String id;
                String title;
                //id = cursor.getString(0);
                title = cursor.getString(2);

                dataProvider = new DataProvider(title);
                cat1FragAdapter.add(dataProvider);

            } while (cursor.moveToNext());
        }

        return rootView;
    }

片段代码：

03-07 12:49:18.775 11190-11190/com.tellfa.dastanak E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.tellfa.dastanak, PID: 11190
android.database.sqlite.SQLiteException: no such table: tbl_Book (code 1): , while compiling: SELECT * FROM tbl_Book WHERE Cat_ID = ?
at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:897)
at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:508)
at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:726)
at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
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:1426)
at android.database.sqlite.SQLiteDatabase.rawQuery(SQLiteDatabase.java:1365)
at com.tellfa.dastanak.Database.DataBase.getCat1_Datas(DataBase.java:157)
at com.tellfa.dastanak.Fragments.Home_Frag.onCreateView(Home_Frag.java:49)
at android.support.v4.app.Fragment.performCreateView(Fragment.java:1962)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1067)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1248)
at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:738)
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1613)
at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:570)
at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:141)
at android.support.v4.view.ViewPager.populate(ViewPager.java:1106)
at android.support.v4.view.ViewPager.populate(ViewPager.java:952)
at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1474)
at android.view.View.measure(View.java:17496)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5466)
at android.support.design.widget.CoordinatorLayout.onMeasureChild(CoordinatorLayout.java:610)
at android.support.design.widget.CoordinatorLayout.onMeasure(CoordinatorLayout.java:677)
at android.view.View.measure(View.java:17496)
at android.support.v4.widget.DrawerLayout.onMeasure(DrawerLayout.java:940)
at android.view.View.measure(View.java:17496)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5466)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:430)
at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:135)
at android.view.View.measure(View.java:17496)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5466)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1438)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:724)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:615)
at android.view.View.measure(View.java:17496)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5466)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:430)
at android.view.View.measure(View.java:17496)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5466)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1438)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:724)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:615)
at android.view.View.measure(View.java:17496)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5466)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:430)
at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2636)
at android.view.View.measure(View.java:17496)
at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2031)
at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1193)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1400)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1078)
at android.view.Vi

public class DataBase extends SQLiteOpenHelper {

    private static String DB_PATH = "";
    private static String DB_NAME = "Dastansara";
    private static int DB_VERSION = 1;
    private SQLiteDatabase sqLiteDatabase;
    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 DataBase(Context context) {
        super(context, DB_NAME, null, DB_VERSION);

        if (android.os.Build.VERSION.SDK_INT >= 17) {
            DB_PATH = context.getApplicationInfo().dataDir + "/databases/";
        } else {
            DB_PATH = "/data/data/" + context.getPackageName() + "/databases/";
        }

        this.myContext = context;
    }

    @Override
    public void onCreate(SQLiteDatabase db) {

    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    }

    /**
     * Creates a empty database on the system and rewrites it with your own database.
     */
    public void createDataBase() throws IOException {

        boolean dbExist = checkDataBase();
        if (dbExist) {
            // do nothing - database alerdy exist
        } else {

            this.getReadableDatabase();

            try {
                copyDataBase();
            } catch (IOException e) {
                throw new Error("Error copying database");
            }
        }
    }

    /**
     * Check if the database already exist to avoid re-copying the file each time you open the application.
     *
     * @return true if it exists, false if it doesn't
     */
    public boolean checkDataBase() {

        SQLiteDatabase checkDB = null;
        try {
            String myPATH = DB_PATH + DB_NAME;
            checkDB = SQLiteDatabase.openDatabase(myPATH, null, SQLiteDatabase.OPEN_READONLY);

        } catch (SQLiteException e) {
            /// database does't exist yet
        }

        if (checkDB != null) {
            checkDB.close();
        }
        return checkDB != null ? true : false;
    }

    /**
     * Open DataBase
     *
     * @throws SQLException
     */
    public void openDataBase() throws SQLException {

        String myPATH = DB_PATH + DB_NAME;
        sqLiteDatabase = SQLiteDatabase.openDatabase(myPATH, null, SQLiteDatabase.OPEN_READONLY);
    }

    /**
     * Close DataBase
     */
    public void closeDataBase() {

        sqLiteDatabase.close();
    }

    /**
     * Copies your database from your local assets-folder to the just created empty database in the
     * system folder, from where it can be accessed and handled.
     * This is done by transfering bytestream.
     */
    public void copyDataBase() throws IOException {

        //Open your local db as the input stream
        InputStream myInput = myContext.getAssets().open(DB_NAME);
        // Path to the just created empty db
        String myPath = DB_PATH + DB_NAME;
        //Open the empty db as the output stream
        OutputStream myOutput = new FileOutputStream(myPath);

        byte[] buffer = new byte[1024];
        int length;
        //transfer bytes from the inputfile to the outputfile
        while ((length = myInput.read(buffer)) > 0) {
            myOutput.write(buffer, 0, length);
        }
        //Close the streams
        myOutput.flush();
        myOutput.close();
        myInput.close();
    }

    @Override
    public synchronized void close() {
        if (sqLiteDatabase != null) {
            sqLiteDatabase.close();
        }
        super.close();
    }

    public Cursor getCat1_Datas(SQLiteDatabase sqLiteDatabase) {

        try {
            String query = "SELECT * FROM tbl_Book WHERE Cat_ID = ?";

            Cursor cursor = sqLiteDatabase.rawQuery(query, new String[] {"1"});

            if (cursor != null) {
                cursor.moveToNext();
            }
            return cursor;
        } catch (SQLException e) {
            Log.e("Data Adapter", "getTestData >>" + e.toString());
            throw e;
        }
    }
}

public class Home_Frag extends Fragment {

    DataProvider dataProvider;
    DataBase dataBase;
    SQLiteDatabase sqLiteDatabase;
    Cursor cursor;
    ListView listView;
    Cat1_frag_adapter cat1FragAdapter;
    private LoadDB_AsyncTask task;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.frag_home,
                container, false);

        task = new LoadDB_AsyncTask(getContext());
        task.execute();

        dataBase = new DataBase(getActivity());
        sqLiteDatabase = dataBase.getReadableDatabase();
        cursor = dataBase.getCat1_Datas(sqLiteDatabase);

        listView = (ListView) rootView.findViewById(R.id.list);
        cat1FragAdapter = new Cat1_frag_adapter(getActivity(), R.layout.list_card_layout);
        listView.setAdapter(cat1FragAdapter);

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            listView.setNestedScrollingEnabled(true);
        }

        if (cursor.moveToFirst()) {
            do {
                String id;
                String title;
                //id = cursor.getString(0);
                title = cursor.getString(2);

                dataProvider = new DataProvider(title);
                cat1FragAdapter.add(dataProvider);

            } while (cursor.moveToNext());
        }

        return rootView;
    }

---

如何修复此错误并在我的应用程序中使用

Asynctask

？tnx在DBHandler类的onCreate中创建数据库表。（替换表名和列）

助手类

DBHandler类：

public class DBHandler {
     private static String TAG = "DBHandler";
    static File dir = new File(Environment.getExternalStorageDirectory() + "");
    private static String MYDATABASE_NAME = dir + "/test/tablename.db";// dir+"/


    public static final String MYDATABASE_TABLE = "tablename";
    public static final int MYDATABASE_VERSION = 1;
    public static final String KEY_TDATE  = "TDATE" ;
    public static final String KEY_TARIFFFCBASIS = "TARIFFFCBASIS" ;



    private static final String SCRIPT_CREATE_DATABASE = "create table "
            + MYDATABASE_TABLE + " (" + KEY_ID
            + " integer primary key autoincrement, "
            +KEY_TDATE  + " text , "
                        +KEY_TARIFFFCBASIS  + "  text  );"


    private SQLiteHelper sqLiteHelper;
    private SQLiteDatabase sqLiteDatabase;

    private Context context;

    public DBHandler(Context c) {
        context = c;
         if(logger == null){
                logger = MasterLibraryFunction.getlogger(context, TAG);
                logger.info("In Side DBHandler(Context c)");
         }
    }

    public DBHandler openToRead() throws android.database.SQLException {
        sqLiteHelper = new SQLiteHelper(context, MYDATABASE_NAME, null,
                MYDATABASE_VERSION);
        sqLiteDatabase = sqLiteHelper.getReadableDatabase();
        return this;
    }

    public DBHandler openToWrite() throws android.database.SQLException {
        sqLiteHelper = new SQLiteHelper(context, MYDATABASE_NAME, null,
                MYDATABASE_VERSION);
        sqLiteDatabase = sqLiteHelper.getWritableDatabase();
        return this;
    }

    public void close() {
        sqLiteHelper.close();
    }
    /**
     * Check if the database exist
     * 
     * @return true if it exists, false if it doesn't
     */
    public boolean checkDataBase() {
        SQLiteDatabase checkDB = null;
        try {
            checkDB = SQLiteDatabase.openDatabase(MYDATABASE_NAME, null,
                    SQLiteDatabase.OPEN_READONLY);
            checkDB.close();
        } catch (SQLiteException e) {
            // database doesn't exist yet.
        }
        return checkDB != null ? true : false;
    }

    public int deleteAll() {
        return sqLiteDatabase.delete(MYDATABASE_TABLE, null, null);
    }

    public class SQLiteHelper extends SQLiteOpenHelper {

        public SQLiteHelper(Context context, String name,
                CursorFactory factory, int version) {

            super(context, name, factory, version);
        }

        @Override
        public void onCreate(SQLiteDatabase db) {
            // TODO Auto-generated method stub
            db.execSQL(SCRIPT_CREATE_DATABASE); 
        }
    }
    }

异步任务代码：

     private class AsyncTaskRunner extends AsyncTask<String, String, String> {

      private String resp;

      @Override
      protected String doInBackground(String... params) {

      // Open DB file to write/read 
      db_helper = new DBHandler(getApplicationContext());
                db_helper.openToWrite();
// Complete your operation and close db_helper 
       return resp;
      }


      @Override
      protected void onPostExecute(String result) {
      // execution of result of Long time consuming operation
      }


          @Override
          protected void onPreExecute() {
           // Things to be done before execution of long running operation. For
       // example showing ProgessDialog
          }



     }
    }

私有类AsyncTaskRunner扩展了AsyncTask{
私有字符串resp；
@凌驾
受保护的字符串doInBackground（字符串…参数）{
//打开数据库文件以进行写入/读取
db_helper=newdbhandler（getApplicationContext（））；
db_helper.openToWrite（）；
//完成您的操作并关闭db_helper
返回响应；
}
@凌驾
受保护的void onPostExecute（字符串结果）{
//执行耗时较长的操作的结果
}
@凌驾
受保护的void onPreExecute（）{
//在执行长时间运行的操作之前要做的事情
//显示ProgesDialog的示例
}
}
}

@elefasGR，你能给我发送示例代码吗？Thankstory它看起来像是用名称

Dastansara

从应用程序的资产目录复制数据库。因此，我想您必须在

checkDataBase

或

createDataBase

中查看复制是否因某种原因失败，当然还要检查您复制的数据库（名为

Dastansara

）是否有您提到的正确表。@elefasGR，请发送代码：（我真的需要这个。请：（如果您不尝试至少回答我之前评论中的问题，则无法向您发送代码。正如我所写，您似乎从资产文件夹中复制了一个文件名为

Dastansara

的数据库。然后您尝试查询该数据库。您必须告诉我们两件事：a）

checkDataBase

或

createDataBase

是否成功完成，b）

Dastansara

数据库是否有您要查询的表

tbl_Book

。请提供准确答案以帮助您。OP看起来像是在从其资产文件夹复制现有数据库，因此可能不想运行脚本“创建”一个新的，因为这将覆盖现有的。谢谢我亲爱的朋友，但我用

SQLite Expert

应用程序创建了数据库，并填充了许多数据！如果我在adnroid中创建数据库，请删除数据库数据。如何使其适合此用途solution@erere如果你已经创建了db文件，那么你需要在文件路径中提到表名。请检查一下。@GmasterCm，什么是DBTariffHandler？你能给我发送这个类代码吗？我已经添加了DBhelpre类，你可以引用它