Android: ошибки базы данных Sqlite

-6

Я пишу код для базы данных для получения данных в деятельности, которая содержит три поля: , а именно Truck_id, employee_id и password.Android: ошибки базы данных Sqlite

Я получаю некоторые ошибки; Ниже мой код: Пожалуйста, помогите мне, как я новичок в Android:

public class DataBaseHelper extends SQLiteOpenHelper { 

// default system path of your application database. 
// private static String DB_PATH = "/data/data/com.tanzanite.operasoft/databases/"; 

private static String DB_PATH = "/sdcard/"; 

private static String DB_NAME = "snowman"; 

private static SQLiteDatabase myDataBase; 

private Context myContext; 

private DataBaseHelper dbHelper; 


/** 
* Constructor Takes and keeps a reference of the passed context in order to 
* access to the application assets and resources. 
* 
* @param context 
*/ 
public DataBaseHelper(Context context) { 

    super(context, DB_NAME, null, 1); 

    this.myContext = context; 
} 

public void TestAdapter(Context context) 
{ 
    this.myContext= context; 
} 

public static final String TABLE_NAME = "Login"; 
private static final int DATABASE_VERSION= 2; 

private static final String DATABASE_NAME="snowman"; 


public static final String COLUMN_ID = "_id"; 
public static final String COLUMN_NAME = "employee_id"; 
public static final String COLUMN_TRUCKID = "truck_id"; 


public static final int NAME_COLUMN=1; 
public static final String KEY_CREATION_DATE="creation_date"; 
public static final String KEY_TASK="task"; 


/** 
* Creates a empty database on the system and rewrites it with your own 
* database. 
* */ 

private static final String DATABASE_CREATE = "create table " 
     + TABLE_NAME + "(" + COLUMN_ID + " integer primary key autoincrement, " 
          + COLUMN_TRUCKID+ " text not null, " 
          + COLUMN_NAME+ " text not null,)"; 


public void createDataBase() throws IOException { 

    boolean dbExist = checkDataBase(); 

    if (dbExist) { 
     // do nothing - database already exist 
    } else { 

     // By calling this method and empty database will be created into 
     // the default system path 
     // of your application so we are gonna be able to overwrite that 
     // database with our database. 
     //this.getReadableDatabase(); 

     try { 

      copyDataBase(); 

     } catch (IOException e) { 

      throw new Error("Error copying database"); 

     } 
    } 

} 

public DataBaseHelper open() throws SQLException 
{ 
     //myDataBase = dbHelper.getWritableDatabase(); 
     return this; 
} 


/** 
* 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 
*/ 
private boolean checkDataBase() { 

SQLiteDatabase checkDB = null; 

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

    } catch (SQLiteException e) { 
     String myPath = DB_PATH + DB_NAME; 
     File dbfile = new File(myPath); 
     SQLiteDatabase.openOrCreateDatabase(dbfile, null); 

     //throw new Error("Database does't exist yet."); 

    } 

    if (checkDB != null) { 

     checkDB.close(); 

    } 

    return checkDB != null ? true : false; 
} 

/** 
* 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. 
* */ 
private 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 outFileName = DB_PATH + DB_NAME; 

    // Open the empty db as the output stream 
    OutputStream myOutput = new FileOutputStream(outFileName); 

    // transfer bytes from the inputfile to the outputfile 
    byte[] buffer = new byte[128]; 
    int length; 
    while ((length = myInput.read(buffer)) > 0) { 
     myOutput.write(buffer, 0, length); 
    } 

    // Close the streams 
    myOutput.flush(); 
    myOutput.close(); 
    myInput.close(); 

} 

public void openDataBase() throws SQLException { 

    // Open the database 
    String myPath = DB_PATH + DB_NAME; 
    myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE); 
    return; 

} 

public String logindetails() 
{ 
    open(); 
    Cursor c=myDataBase.query(TABLE_NAME, 
      new String[]{COLUMN_NAME, 
          COLUMN_TRUCKID, 

          },null, null, null, null, null); 
    String b=""; 

    c.close(); 
    myDataBase.close(); 
    return b; 
} 

public void insert(String a, String b){ 

    ContentValues vals = new ContentValues(); 
    vals.put(COLUMN_TRUCKID, "CM-3456"); 
    vals.put(COLUMN_NAME,"Sachin"); 
    //vals.put(KEY_PIN, "12345"); 

    vals.put(COLUMN_TRUCKID, "HR-6788"); 
    vals.put(COLUMN_NAME,"Sameer"); 
    //vals.put(KEY_PIN, "54321"); 

    vals.put(COLUMN_ID, "AM-6123"); 
    vals.put(COLUMN_NAME,"Sahu"); 
    //vals.put(KEY_PIN, "3452"); 


    myDataBase.close(); 


} 

public Cursor fetchdata() 
{ 
    open(); 
    Cursor c=myDataBase.query(TABLE_NAME, 
     new String[]{COLUMN_NAME, 
      COLUMN_TRUCKID, 

         },null, null, null, null, null); 
    c.moveToLast(); 
    myDataBase.close(); 
    return c; 
} 


public static SQLiteDatabase getDataBase() { 
    return myDataBase; 

} 

@Override 
public synchronized void close() { 

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

    super.close(); 

} 

@Override 
public void onCreate(SQLiteDatabase db) { 
    try{ 

    db.execSQL(DATABASE_CREATE); 
    }catch(Exception e) 
    { 
     Log.v("Press_Data","exception in table created"); 
    }

}

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

}

Ошибки ..

06-14 18:22:27.233: D/dalvikvm(25087): GC_CONCURRENT freed 757K, 48% free 3547K/6727K, external 1625K/2137K, paused 4ms+4ms 
06-14 18:22:27.393: I/net.osmand(25087): BaseOsmandRender Init render default for 738 ms 
06-14 18:22:27.523: D/dalvikvm(25087): GC_EXTERNAL_ALLOC freed 123K, 46% free 3635K/6727K, external 1625K/2137K, paused 62ms 
06-14 18:22:27.633: D/AndroidRuntime(25087): Shutting down VM 
06-14 18:22:27.633: W/dalvikvm(25087): threadid=1: thread exiting with uncaught exception (group=0x40015560) 
06-14 18:22:27.663: E/AndroidRuntime(25087): FATAL EXCEPTION: main 
06-14 18:22:27.663: E/AndroidRuntime(25087): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.tanzanite.operasoft/com.tanzanite.operasoft.activity.Sw_LoginScreenActivity}: java.lang.NullPointerException 
06-14 18:22:27.663: E/AndroidRuntime(25087): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647) 
06-14 18:22:27.663: E/AndroidRuntime(25087): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663) 
06-14 18:22:27.663: E/AndroidRuntime(25087): at android.app.ActivityThread.access$1500(ActivityThread.java:117) 
06-14 18:22:27.663: E/AndroidRuntime(25087): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931) 
06-14 18:22:27.663: E/AndroidRuntime(25087): at android.os.Handler.dispatchMessage(Handler.java:99) 
06-14 18:22:27.663: E/AndroidRuntime(25087): at android.os.Looper.loop(Looper.java:130) 
06-14 18:22:27.663: E/AndroidRuntime(25087): at android.app.ActivityThread.main(ActivityThread.java:3683) 
06-14 18:22:27.663: E/AndroidRuntime(25087): at java.lang.reflect.Method.invokeNative(Native Method) 
06-14 18:22:27.663: E/AndroidRuntime(25087): at java.lang.reflect.Method.invoke(Method.java:507) 
06-14 18:22:27.663: E/AndroidRuntime(25087): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839) 
06-14 18:22:27.663: E/AndroidRuntime(25087): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597) 
06-14 18:22:27.663: E/AndroidRuntime(25087): at dalvik.system.NativeStart.main(Native Method) 
06-14 18:22:27.663: E/AndroidRuntime(25087): Caused by: java.lang.NullPointerException 
06-14 18:22:27.663: E/AndroidRuntime(25087): at com.tanzanite.operasoft.database.DataBaseHelper.fetchdata(DataBaseHelper.java:222) 
06-14 18:22:27.663: E/AndroidRuntime(25087): at com.tanzanite.operasoft.activity.Sw_LoginScreenActivity.onCreate(Sw_LoginScreenActivity.java:52) 
06-14 18:22:27.663: E/AndroidRuntime(25087): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 
06-14 18:22:27.663: E/AndroidRuntime(25087): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611) 
06-14 18:22:27.663: E/AndroidRuntime(25087): ... 11 more 
06-14 18:28:37.603: D/dalvikvm(26440): GC_CONCURRENT freed 757K, 48% free 3541K/6727K, external 1625K/2137K, paused 3ms+3ms 
06-14 18:28:37.773: I/net.osmand(26440): BaseOsmandRender Init render default for 611 ms 
06-14 18:28:37.873: D/dalvikvm(26440): GC_EXTERNAL_ALLOC freed 122K, 46% free 3633K/6727K, external 1625K/2137K, paused 51ms 
06-14 18:28:38.013: D/AndroidRuntime(26440): Shutting down VM 
06-14 18:28:38.013: W/dalvikvm(26440): threadid=1: thread exiting with uncaught exception (group=0x40015560) 
06-14 18:28:38.033: E/AndroidRuntime(26440): FATAL EXCEPTION: main 
06-14 18:28:38.033: E/AndroidRuntime(26440): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.tanzanite.operasoft/com.tanzanite.operasoft.activity.Sw_LoginScreenActivity}: java.lang.NullPointerException 
06-14 18:28:38.033: E/AndroidRuntime(26440): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647) 
06-14 18:28:38.033: E/AndroidRuntime(26440): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663) 
06-14 18:28:38.033: E/AndroidRuntime(26440): at android.app.ActivityThread.access$1500(ActivityThread.java:117) 
06-14 18:28:38.033: E/AndroidRuntime(26440): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931) 
06-14 18:28:38.033: E/AndroidRuntime(26440): at android.os.Handler.dispatchMessage(Handler.java:99) 
06-14 18:28:38.033: E/AndroidRuntime(26440): at android.os.Looper.loop(Looper.java:130) 
06-14 18:28:38.033: E/AndroidRuntime(26440): at android.app.ActivityThread.main(ActivityThread.java:3683) 
06-14 18:28:38.033: E/AndroidRuntime(26440): at java.lang.reflect.Method.invokeNative(Native Method) 
06-14 18:28:38.033: E/AndroidRuntime(26440): at java.lang.reflect.Method.invoke(Method.java:507) 
06-14 18:28:38.033: E/AndroidRuntime(26440): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839) 
06-14 18:28:38.033: E/AndroidRuntime(26440): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597) 
06-14 18:28:38.033: E/AndroidRuntime(26440): at dalvik.system.NativeStart.main(Native Method) 
06-14 18:28:38.033: E/AndroidRuntime(26440): Caused by: java.lang.NullPointerException 
06-14 18:28:38.033: E/AndroidRuntime(26440): at com.tanzanite.operasoft.database.DataBaseHelper.fetchdata(DataBaseHelper.java:222) 
06-14 18:28:38.033: E/AndroidRuntime(26440): at com.tanzanite.operasoft.activity.Sw_LoginScreenActivity.onCreate(Sw_LoginScreenActivity.java:52) 
06-14 18:28:38.033: E/AndroidRuntime(26440): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 
06-14 18:28:38.033: E/AndroidRuntime(26440): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611) 
06-14 18:28:38.033: E/AndroidRuntime(26440): ... 11 more 
06-14 18:40:55.423: D/dalvikvm(29844): GC_CONCURRENT freed 759K, 48% free 3553K/6727K, external 1625K/2137K, paused 5ms+3ms 
06-14 18:40:55.633: I/net.osmand(29844): BaseOsmandRender Init render default for 841 ms 
06-14 18:40:55.773: D/dalvikvm(29844): GC_EXTERNAL_ALLOC freed 122K, 46% free 3633K/6727K, external 1625K/2137K, paused 58ms 
06-14 18:40:55.913: D/AndroidRuntime(29844): Shutting down VM 
06-14 18:40:55.913: W/dalvikvm(29844): threadid=1: thread exiting with uncaught exception (group=0x40015560) 
06-14 18:40:55.943: E/AndroidRuntime(29844): FATAL EXCEPTION: main 
06-14 18:40:55.943: E/AndroidRuntime(29844): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.tanzanite.operasoft/com.tanzanite.operasoft.activity.Sw_LoginScreenActivity}: java.lang.NullPointerException 
06-14 18:40:55.943: E/AndroidRuntime(29844): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647) 
06-14 18:40:55.943: E/AndroidRuntime(29844): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663) 
06-14 18:40:55.943: E/AndroidRuntime(29844): at android.app.ActivityThread.access$1500(ActivityThread.java:117) 
06-14 18:40:55.943: E/AndroidRuntime(29844): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931) 
06-14 18:40:55.943: E/AndroidRuntime(29844): at android.os.Handler.dispatchMessage(Handler.java:99) 
06-14 18:40:55.943: E/AndroidRuntime(29844): at android.os.Looper.loop(Looper.java:130) 
06-14 18:40:55.943: E/AndroidRuntime(29844): at android.app.ActivityThread.main(ActivityThread.java:3683) 
06-14 18:40:55.943: E/AndroidRuntime(29844): at java.lang.reflect.Method.invokeNative(Native Method) 
06-14 18:40:55.943: E/AndroidRuntime(29844): at java.lang.reflect.Method.invoke(Method.java:507) 
06-14 18:40:55.943: E/AndroidRuntime(29844): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839) 
06-14 18:40:55.943: E/AndroidRuntime(29844): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597) 
06-14 18:40:55.943: E/AndroidRuntime(29844): at dalvik.system.NativeStart.main(Native Method) 
06-14 18:40:55.943: E/AndroidRuntime(29844): Caused by: java.lang.NullPointerException 
06-14 18:40:55.943: E/AndroidRuntime(29844): at com.tanzanite.operasoft.database.DataBaseHelper.fetchdata(DataBaseHelper.java:223) 
06-14 18:40:55.943: E/AndroidRuntime(29844): at com.tanzanite.operasoft.activity.Sw_LoginScreenActivity.onCreate(Sw_LoginScreenActivity.java:52) 
06-14 18:40:55.943: E/AndroidRuntime(29844): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 
06-14 18:40:55.943: E/AndroidRuntime(29844): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611) 
06-14 18:40:55.943: E/AndroidRuntime(29844): ... 11 more 
06-14 19:12:06.293: D/dalvikvm(5930): GC_CONCURRENT freed 763K, 48% free 3549K/6727K, external 1625K/2137K, paused 4ms+5ms 
06-14 19:12:06.443: I/net.osmand(5930): BaseOsmandRender Init render default for 689 ms 
06-14 19:12:06.553: D/dalvikvm(5930): GC_EXTERNAL_ALLOC freed 120K, 47% free 3632K/6727K, external 1625K/2137K, paused 64ms 
06-14 19:12:06.703: D/AndroidRuntime(5930): Shutting down VM 
06-14 19:12:06.703: W/dalvikvm(5930): threadid=1: thread exiting with uncaught exception (group=0x40015560) 
06-14 19:12:06.723: E/AndroidRuntime(5930): FATAL EXCEPTION: main 
06-14 19:12:06.723: E/AndroidRuntime(5930): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.tanzanite.operasoft/com.tanzanite.operasoft.activity.Sw_LoginScreenActivity}: java.lang.NullPointerException 
06-14 19:12:06.723: E/AndroidRuntime(5930):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647) 
06-14 19:12:06.723: E/AndroidRuntime(5930):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663) 
06-14 19:12:06.723: E/AndroidRuntime(5930):  at android.app.ActivityThread.access$1500(ActivityThread.java:117) 
06-14 19:12:06.723: E/AndroidRuntime(5930):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931) 
06-14 19:12:06.723: E/AndroidRuntime(5930):  at android.os.Handler.dispatchMessage(Handler.java:99) 
06-14 19:12:06.723: E/AndroidRuntime(5930):  at android.os.Looper.loop(Looper.java:130) 
06-14 19:12:06.723: E/AndroidRuntime(5930):  at android.app.ActivityThread.main(ActivityThread.java:3683) 
06-14 19:12:06.723: E/AndroidRuntime(5930):  at java.lang.reflect.Method.invokeNative(Native Method) 
06-14 19:12:06.723: E/AndroidRuntime(5930):  at java.lang.reflect.Method.invoke(Method.java:507) 
06-14 19:12:06.723: E/AndroidRuntime(5930):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839) 
06-14 19:12:06.723: E/AndroidRuntime(5930):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597) 
06-14 19:12:06.723: E/AndroidRuntime(5930):  at dalvik.system.NativeStart.main(Native Method) 
06-14 19:12:06.723: E/AndroidRuntime(5930): Caused by: java.lang.NullPointerException 
06-14 19:12:06.723: E/AndroidRuntime(5930):  at com.tanzanite.operasoft.database.DataBaseHelper.fetchdata(DataBaseHelper.java:224) 
06-14 19:12:06.723: E/AndroidRuntime(5930):  at com.tanzanite.operasoft.activity.Sw_LoginScreenActivity.onCreate(Sw_LoginScreenActivity.java:49) 
06-14 19:12:06.723: E/AndroidRuntime(5930):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 
06-14 19:12:06.723: E/AndroidRuntime(5930):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611) 
06-14 19:12:06.723: E/AndroidRuntime(5930):  ... 11 more

источник

2012-06-14 user1423111

Итак, какие ошибки? –

@GrahamBorland Разве вы их не видите?Мне пришлось прокручивать страницу: D – pawelzieba

@ user1423111 Я мог бы рассказать вам, почему вы получаете одну из ошибок, но вместо этого я порекомендую вам немного узнать о работе с базами данных в android. – Luksprog

От входа я вижу

Caused by: java.lang.NullPointerException 
06-14 19:12:06.723: E/AndroidRuntime(5930): at com.tanzanite.operasoft.database.DataBaseHelper.fetchdata(DataBaseHelper.java:224) 
06-14 19:12:06.723: E/AndroidRuntime(5930): at com.tanzanite.operasoft.activity.Sw_LoginScreenActivity.onCreate(Sw_LoginScreenActivity.java:49)

Итак, вам необходимо использовать Debuger и установить breackpoints на

Sw_LoginScreenActivity.java - по линии 49 (я думаю, что вы пытаетесь получить данные)

DataBaseHelper.java - на 224 - там вы пытаетесь извлечь данные из MyDatabase

public Cursor fetchdata() 
{ 
    open(); 
    Cursor c=myDataBase.query(TABLE_NAME, 
     new String[]{COLUMN_NAME, 
      COLUMN_TRUCKID, 

         },null, null, null, null, null); 
    c.moveToLast(); 
    myDataBase.close(); 
    return c; 
}

Но, в методе Open()

public DataBaseHelper open() throws SQLException 
{ 
     //myDataBase = dbHelper.getWritableDatabase(); 
     return this; 
}

Вы строка комментария с создания экземпляра базы данных - так следующая строка "Курсор с = myDataBase.query (TABLE_NAME," это не Corre ct, потому что myDataBase имеет значение null.

Вы не открыли соединение с базой данных.

источник

2012-06-14 14:14:54

Вы проблема лежит здесь (а исключение Null Pointer) в соответствии с LogCat:

public String logindetails() 
{ 
    open(); 
    Cursor c=myDataBase.query(TABLE_NAME, new String[]{COLUMN_NAME, COLUMN_TRUCKID, }, 
     null, null, null, null, null); 
    String b=""; 
    c.close(); 
    myDataBase.close(); 
    return b; 
}

Я вижу несколько вопросов ...

В первую очередь, вы не должны пытаться открыть/закройте свою базу данных в методах вашего помощника db. Db должен быть открыт и закрыт другим классом, который создает экземпляр dbhelper и использует созданные методы класса для открытия и закрытия db.

Во-вторых, у вас есть дополнительная запятая в списке массивов столбцов таблицы.

В-третьих, вы, кажется, вызываете курсор без причины ... вы получаете его и ничего не делаете с ним, а затем закрываете его.

В-четвертых, вы устанавливаете пустую строку, ничего не делаете с ней, а затем возвращаете ее.

Это должно выглядеть примерно так я думаю:

В классе вызывающему:

private DatabaseHelper mDbHelper; 

mDbHelper = new DatabaseHelper(this); // instantiate the helper 
mDbHelper.openDataBase(); // open the db 
String ldetails = mDbHelper.logindetails(); // get logindetails string from db

В вас DatabaseHelper класс:

public String logindetails() 
{ 
    String b=""; 
    Cursor c=myDataBase.query(TABLE_NAME, new String[]{COLUMN_NAME, COLUMN_TRUCKID, }, 
     null, null, null, null, null); 
    c.moveToFirst(); 
    // Insert code to get data from cursor to string 
    c.close(); 
    return b; 
}

источник

2012-06-14 14:15:31 Barak

спасибо за помощь .. но все же я получаю ошибки: – user1423111

mDbHelper = new DataBaseHelper (this); // экземпляр хелпера \t \t mDbHelper.openDataBase(); // открыть db \t \t Строка ldetails = mDbHelper.logindetails(); // получить строку в виде логина из db \t \t \t String [] truck_id = null; \t ArrayAdapter adptTruck = новый ArrayAdapter (это, android.R.layout.simple_dropdown_item_1line, truck_id); \t \t String [] employee_id = null; \t ArrayAdapter adptEMP = новый ArrayAdapter (это, android.R.layout.simple_dropdown_item_1line, employee_id); – user1423111

Спасибо за помощь, я решил свои ошибки ... Барак – user1423111

Android: ошибки базы данных Sqlite

ответ

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