sqlite3_open_v2("/ data/data/com.food.find/databases/mydatabase",&handle,2,NULL)在android中失败了吗？

Question

我试图从资产创建数据库但是给我错误无法打开数据库,但我再次运行后不给错误是完成运行第一次创建是给我错误我把我的logcat这里

07-04 18:28:00.860: E/Database(990): sqlite3_open_v2("/data/data/com.temp.find/databases/tempfind", &handle, 2, NULL) failed
07-04 18:28:00.870: W/System.err(990): android.database.sqlite.SQLiteException: unable to open database file
07-04 18:28:00.880: W/System.err(990):  at android.database.sqlite.SQLiteDatabase.dbopen(Native Method)
07-04 18:28:00.880: W/System.err(990):  at android.database.sqlite.SQLiteDatabase.<init>(SQLiteDatabase.java:1849)
07-04 18:28:00.880: W/System.err(990):  at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:820)
07-04 18:28:00.880: W/System.err(990):  at com.food.find.RestaurantDatabase.checkDataBase(RestaurantDatabase.java:97)
07-04 18:28:00.890: W/System.err(990):  at com.food.find.RestaurantDatabase.createDataBase(RestaurantDatabase.java:60)
07-04 18:28:00.890: W/System.err(990):  at com.food.find.SplashScreenActivity.onCreate(SplashScreenActivity.java:25)
07-04 18:28:00.890: W/System.err(990):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
07-04 18:28:00.890: W/System.err(990):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
07-04 18:28:00.890: W/System.err(990):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
07-04 18:28:00.890: W/System.err(990):  at android.app.ActivityThread.access$1500(ActivityThread.java:117)
07-04 18:28:00.900: W/System.err(990):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
07-04 18:28:00.900: W/System.err(990):  at android.os.Handler.dispatchMessage(Handler.java:99)
07-04 18:28:00.900: W/System.err(990):  at android.os.Looper.loop(Looper.java:123)
07-04 18:28:00.900: W/System.err(990):  at android.app.ActivityThread.main(ActivityThread.java:3683)
07-04 18:28:00.900: W/System.err(990):  at java.lang.reflect.Method.invokeNative(Native Method)
07-04 18:28:00.900: W/System.err(990):  at java.lang.reflect.Method.invoke(Method.java:507)
07-04 18:28:00.900: W/System.err(990):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
07-04 18:28:00.900: W/System.err(990):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
07-04 18:28:00.910: W/System.err(990):  at dalvik.system.NativeStart.main(Native Method)
07-04 18:28:01.030: E/running(990): database opened page size

RestaurantDatabase.java

public class RestaurantDatabase extends SQLiteOpenHelper{


    // Contacts Table Columns names
    private static final String KEY_ID = "id";
    private static final String KEY_NAME = "name";
    private static final String KEY_FOODADDRESS="address";
    private static final String KEY_FOODPHONE = "phonenumber";
    private static final String KEY_LATITUDE="latitude";
    private static final String KEY_LONGITUDE="longitude";



    private static final String TAG_LAT="lat";
    private static final String TAG_LONG="lng";
    private static final String TAG_RESPONSE = "responseData";
    private static final String TAG_TITLENOFORMATING = "titleNoFormatting";
    private static final String TAG_ADDRESSLINES="addressLines";
    private static final String TAG_PHONENUMBERS="phoneNumbers";
    private static final String TAG_NUMBER="number";    
    private static final String TAG_FOOD="food";
    private static String DB_PATH ="/data/data/com.temp.find/databases/";   
    private static String DB_NAME ="tempfind";   
    private SQLiteDatabase myDataBase; 
    private final Context myContext;    

    String query = "";

    public RestaurantDatabase(Context context)
    {
        super(context, DB_NAME, null, 1);
        this.myContext=context;     
    };

    public void createDataBase() throws IOException
    {

         boolean dbExist = checkDataBase();

         if(dbExist)
         {

         }
         else
         {


         this.getReadableDatabase();

         try
         {

             copyDataBase();

         } 
         catch (IOException e)
         {

             throw new Error("Error copying database");

         }

         }


    }


    private boolean checkDataBase()
    {

        SQLiteDatabase checkDB = null;

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

        }
        catch(SQLiteException e)
        {   
            e.printStackTrace();
        }

        if(checkDB != null)
        {
            checkDB.close();
        }

        return checkDB != null ? true : false;
    }


    private void copyDataBase() throws IOException
    {


        InputStream myInput = myContext.getAssets().open(DB_NAME);

        String outFileName = DB_PATH + DB_NAME;
        OutputStream myOutput = new FileOutputStream(outFileName);

        //transfer bytes from the inputfile to the outputfile
        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 RestaurantDatabase(Context context, String name, CursorFactory factory,int version) 
    {
        super(context, name, factory, version);
        this.myContext=context;
    }


        public void openDataBase() throws SQLException
        {     
                //Open the database
                String myPath = DB_PATH + DB_NAME;
                myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);
                Log.e("running", "database opened page size");

        }

        @Override
        public synchronized void close() 
        {

            if(myDataBase != null)
                myDataBase.close(); 
            super.close();

        }



    @Override
    public void onCreate(SQLiteDatabase db) {
        // TODO Auto-generated method stub

    }

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


    }

    public String addContact(String title,String address,String phone,String latitude,String longitude) 
    {

        String check = null;

        Log.e("Title","--->"+title);
        Log.e("Address","-->"+address);
        Log.e("Number","-->"+phone);
        Log.e("Latitude","-->"+latitude);
        Log.e("Longitude","-->"+longitude);

        ContentValues values = new ContentValues();
        values.put(KEY_NAME,title); // Contact Name
        values.put(KEY_FOODADDRESS,address); // Contact Address
        values.put(KEY_FOODPHONE,phone); // Contact Phone
        values.put(KEY_LATITUDE,latitude); // Contact Latitude
        values.put(KEY_LONGITUDE,longitude); // Contact Longitude

        Log.e("addcontact called","--->");

        // Inserting Row
        myDataBase.insert(TAG_FOOD, null,values);       

        String selectQuery = " SELECT  * FROM " + TAG_FOOD ;

        Cursor cursor = myDataBase.rawQuery(selectQuery, null);

        Log.e("CURSOR RECORD","--->"+cursor.getCount());
        Log.e("INSERT RECORD","--->"+values);


        return check;


    }



}

Answer 1

这段代码很糟糕.我首先要删除整个内容并重新开始.

首先,如果您要使用应用程序打包数据库,请不要为此编写自己的代码.有一个现有的库,SQLiteAssetHelper经过测试,调试和支持.更重要的是,它是由某人(Jeff Gilfelt)编写的,具有很多 Android开发经验.

其次,如果您正在使用SQLiteOpenHelper(或类似的子类SQLiteAssetHelper),并且您也在openDatabase()为该数据库编写任何地方,那么您的错误就是错误.完整和整个点背后SQLiteOpenHelper是有它打开数据库给你,所以它可以创建或者如果需要升级数据库.

第三,如果您正在使用SQLiteOpenHelper(或类似的子类SQLiteAssetHelper),并且您已经清空了一个空onCreate()方法,那么您做错了.这里需要有代码来实际创建数据库,无论是您继承的代码(例如,来自SQLiteAssetHelper)还是您编写的代码.

第四,如果你正在使用SQLiteOpenHelper(或子类一样SQLiteAssetHelper),而你打电话getReadableDatabase()或getWriteableDatabase()和被忽略的返回值,你做错了.您调用这些方法来打开数据库,为您SQLiteDatabase提供使用方法.

这段代码有很多错误,但这应该足以让你更接近合理的实现.