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AndroidでSQLiteのテーブルからすべてのレコードを削除する方法?

私のアプリには2つのボタンがあり、最初のボタンはユーザー入力のレコードを削除するためのもので、2番目のボタンはすべてのレコードを削除するためのものです。しかし、私がデータを削除したいとき、それはメッセージを示します
「あなたのアプリケーションは強制的に停止されました」。

私のコードをチェックして、私に何か提案をください。

public void deleteAll()
{
    //SQLiteDatabase db = this.getWritableDatabase();
   // db.delete(TABLE_NAME,null,null);
    //db.execSQL("delete * from"+ TABLE_NAME);
    db.execSQL("TRUNCATE table" + TABLE_NAME);
    db.close();
}

そして

public void delete(String id)
{
    String[] args={id};
    getWritableDatabase().delete("texts", "_ID=?", args);
}

しかし、それは以下のLog catエラーを示しています。

03-07 15:57:07.143: ERROR/AndroidRuntime(287): Uncaught handler: thread main exiting due to uncaught exception
03-07 15:57:07.153: ERROR/AndroidRuntime(287): Java.lang.NullPointerException
03-07 15:57:07.153: ERROR/AndroidRuntime(287):     at com.example.MySQLiteHelper.delete(MySQLiteHelper.Java:163)
03-07 15:57:07.153: ERROR/AndroidRuntime(287):     at com.example.Settings$4.onClick(Settings.Java:94)
-07 15:57:07.153: ERROR/AndroidRuntime(287):     at com.Android.internal.app.AlertController$ButtonHandler.handleMessage(AlertController.Java:158)
03-07 15:57:07.153: ERROR/AndroidRuntime(287):     at Android.os.Handler.dispatchMessage(Handler.Java:99)
03-07 15:57:07.153: ERROR/AndroidRuntime(287):     at Android.os.Looper.loop(Looper.Java:123)
03-07 15:57:07.153: ERROR/AndroidRuntime(287):     at Android.app.ActivityThread.main(ActivityThread.Java:4203)
03-07 15:57:07.153: ERROR/AndroidRuntime(287):     at Java.lang.reflect.Method.invokeNative(Native Method)
03-07 15:57:07.153: ERROR/AndroidRuntime(287):     at Java.lang.reflect.Method.invoke(Method.Java:521)
03-07 15:57:07.153: ERROR/AndroidRuntime(287):     at com.Android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.Java:791)
03-07 15:57:07.153: ERROR/AndroidRuntime(287):     at com.Android.internal.os.ZygoteInit.main(ZygoteInit.Java:549)
03-07 15:57:07.153: ERROR/AndroidRuntime(287):     at dalvik.system.NativeStart.main(Native Method)
149

あなたはスペースを逃しました:db.execSQL("delete * from " + TABLE_NAME);

また、*を含める必要さえない、正しいクエリは次のとおりです。

db.execSQL("delete from "+ TABLE_NAME);
319
viplezer
db.delete(TABLE_NAME, null, null);

関数に削除された行の数を返す場合は、

db.delete(TABLE_NAME, "1", null);

SQLiteDatabaseのドキュメントから 削除 メソッド:

すべての行を削除してカウントを取得するには、whereClauseとして "1"を渡します。

153
Paolo M

テーブル内のすべての行を削除するには、次のようにします。

db.delete(TABLE_NAME, null, null);
41
Burakito

SQLiteはTRUNCATEコマンドをサポートしていません。前の行で試したものを使用する必要があります。

DELETE FROM `TABLE_NAME`;

P.Sクエリごとに新しいデータベースを作成するのではなく、特定のデータベースへのすべてのクエリに対してデータベース接続の同じインスタンスを使用することで、プログラムを最適化できます。

25
Itay Grudev

"execute"関数を使う必要はありません。次のコードが私のために働きました:::

    db.delete(TABLE_NAME,null,null);
    db.close();
18
gaurav
SQLiteDatabase db = this.getWritableDatabase();
        db.execSQL("DELETE FROM tablename"); //delete all rows in a table
db.close();

この仕事は私のために:)

6

このコードを試して、テーブルからすべてのデータを削除してください。

String selectQuery = "DELETE FROM table_name ";
Cursor cursor = data1.getReadableDatabase().rawQuery(selectQuery, null);
5
Gaurav

私はこのクラスを使用してデータベースを処理します。将来的に役立つことを願っています。

ハッピーコーディング.

public class Database {

private static class DBHelper extends SQLiteOpenHelper {

    /**
     * Database name
     */
    private static final String DB_NAME = "db_name";

    /**
     * Table Names
     */
    public static final String TABLE_CART = "DB_CART";


    /**
     *  Cart Table Columns
     */
    public static final String CART_ID_PK = "_id";// Primary key

    public static final String CART_DISH_NAME = "dish_name";
    public static final String CART_DISH_ID = "menu_item_id";
    public static final String CART_DISH_QTY = "dish_qty";
    public static final String CART_DISH_PRICE = "dish_price";

    /**
     * String to create reservation tabs table
     */
    private final String CREATE_TABLE_CART = "CREATE TABLE IF NOT EXISTS "
            + TABLE_CART + " ( "
            + CART_ID_PK + " INTEGER PRIMARY KEY, "
            + CART_DISH_NAME + " TEXT , "
            + CART_DISH_ID + " TEXT , "
            + CART_DISH_QTY + " TEXT , "
            + CART_DISH_PRICE + " TEXT);";


    public DBHelper(Context context) {
        super(context, DB_NAME, null, 2);

    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL(CREATE_TABLE_CART);


    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int arg1, int arg2) {
        db.execSQL("DROP TABLE IF EXISTS " + CREATE_TABLE_CART);
        onCreate(db);
    }

}


     /**
      * CART handler
      */
      public static class Cart {


    /**
     * Check if Cart is available or not
     *
     * @param context
     * @return
     */
    public static boolean isCartAvailable(Context context) {

        DBHelper dbHelper = new DBHelper(context);
        SQLiteDatabase db = dbHelper.getReadableDatabase();
        boolean exists = false;

        try {
            String query = "SELECT * FROM " + DBHelper.TABLE_CART;
            Cursor cursor = db.rawQuery(query, null);
            exists = (cursor.getCount() > 0);
            cursor.close();
            db.close();
        } catch (SQLiteException e) {
            db.close();
        }

        return exists;
    }


    /**
     * Insert values in cart table
     *
     * @param context
     * @param dishName
     * @param dishPrice
     * @param dishQty
     * @return
     */
    public static boolean insertItem(Context context, String itemId, String dishName, String dishPrice, String dishQty) {

        DBHelper dbHelper = new DBHelper(context);
        SQLiteDatabase db = dbHelper.getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put(DBHelper.CART_DISH_ID, "" + itemId);
        values.put(DBHelper.CART_DISH_NAME, "" + dishName);
        values.put(DBHelper.CART_DISH_PRICE, "" + dishPrice);
        values.put(DBHelper.CART_DISH_QTY, "" + dishQty);

        try {
            db.insert(DBHelper.TABLE_CART, null, values);
            db.close();
            return true;
        } catch (SQLiteException e) {
            db.close();
            return false;
        }
    }

    /**
     * Check for specific record by name
     *
     * @param context
     * @param dishName
     * @return
     */
    public static boolean isItemAvailable(Context context, String dishName) {

        DBHelper dbHelper = new DBHelper(context);
        SQLiteDatabase db = dbHelper.getReadableDatabase();
        boolean exists = false;

        String query = "SELECT * FROM " + DBHelper.TABLE_CART + " WHERE "
                + DBHelper.CART_DISH_NAME + " = '" + String.valueOf(dishName) + "'";


        try {
            Cursor cursor = db.rawQuery(query, null);

            exists = (cursor.getCount() > 0);
            cursor.close();

        } catch (SQLiteException e) {

            e.printStackTrace();
            db.close();

        }

        return exists;
    }

    /**
     * Update cart item by item name
     *
     * @param context
     * @param dishName
     * @param dishPrice
     * @param dishQty
     * @return
     */
    public static boolean updateItem(Context context, String itemId, String dishName, String dishPrice, String dishQty) {

        DBHelper dbHelper = new DBHelper(context);
        SQLiteDatabase db = dbHelper.getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put(DBHelper.CART_DISH_ID, itemId);
        values.put(DBHelper.CART_DISH_NAME, dishName);
        values.put(DBHelper.CART_DISH_PRICE, dishPrice);
        values.put(DBHelper.CART_DISH_QTY, dishQty);

        try {

            String[] args = new String[]{dishName};
            db.update(DBHelper.TABLE_CART, values, DBHelper.CART_DISH_NAME + "=?", args);

            db.close();


            return true;
        } catch (SQLiteException e) {
            db.close();

            return false;
        }
    }

    /**
     * Get cart list
     *
     * @param context
     * @return
     */
    public static ArrayList<CartModel> getCartList(Context context) {

        DBHelper dbHelper = new DBHelper(context);
        SQLiteDatabase db = dbHelper.getReadableDatabase();

        ArrayList<CartModel> cartList = new ArrayList<>();

        try {
            String query = "SELECT * FROM " + DBHelper.TABLE_CART + ";";

            Cursor cursor = db.rawQuery(query, null);


            for (cursor.moveToFirst(); !cursor.isAfterLast(); cursor.moveToNext()) {

                cartList.add(new CartModel(
                        cursor.getString(cursor.getColumnIndex(DBHelper.CART_DISH_ID)),
                        cursor.getString(cursor.getColumnIndex(DBHelper.CART_DISH_NAME)),
                        cursor.getString(cursor.getColumnIndex(DBHelper.CART_DISH_QTY)),
                        Integer.parseInt(cursor.getString(cursor.getColumnIndex(DBHelper.CART_DISH_PRICE)))
                ));
            }

            db.close();

        } catch (SQLiteException e) {
            db.close();
        }
        return cartList;
    }

   /**
     * Get total amount of cart items
     *
     * @param context
     * @return
     */
    public static String getTotalAmount(Context context) {

        DBHelper dbHelper = new DBHelper(context);
        SQLiteDatabase db = dbHelper.getReadableDatabase();

        double totalAmount = 0.0;

        try {
            String query = "SELECT * FROM " + DBHelper.TABLE_CART + ";";

            Cursor cursor = db.rawQuery(query, null);


            for (cursor.moveToFirst(); !cursor.isAfterLast(); cursor.moveToNext()) {

                totalAmount = totalAmount + Double.parseDouble(cursor.getString(cursor.getColumnIndex(DBHelper.CART_DISH_PRICE))) *
                        Double.parseDouble(cursor.getString(cursor.getColumnIndex(DBHelper.CART_DISH_QTY)));
            }

            db.close();


        } catch (SQLiteException e) {
            db.close();
        }


        if (totalAmount == 0.0)
            return "";
        else
            return "" + totalAmount;
    }


    /**
     * Get item quantity
     *
     * @param context
     * @param dishName
     * @return
     */
    public static String getItemQty(Context context, String dishName) {

        DBHelper dbHelper = new DBHelper(context);
        SQLiteDatabase db = dbHelper.getReadableDatabase();

        Cursor cursor = null;
        String query = "SELECT * FROM " + DBHelper.TABLE_CART + " WHERE " + DBHelper.CART_DISH_NAME + " = '" + dishName + "';";
        String quantity = "0";

        try {
            cursor = db.rawQuery(query, null);

            if (cursor.getCount() > 0) {

                cursor.moveToFirst();
                quantity = cursor.getString(cursor
                        .getColumnIndex(DBHelper.CART_DISH_QTY));

                return quantity;
            }


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

        return quantity;
    }


    /**
     * Delete cart item by name
     *
     * @param context
     * @param dishName
     */
    public static void deleteCartItem(Context context, String dishName) {
        DBHelper dbHelper = new DBHelper(context);
        SQLiteDatabase db = dbHelper.getReadableDatabase();

        try {

            String[] args = new String[]{dishName};
            db.delete(DBHelper.TABLE_CART, DBHelper.CART_DISH_NAME + "=?", args);

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

    }


}//End of cart class

/**
 * Delete database table
 *
 * @param context
 */
public static void deleteCart(Context context) {
    DBHelper dbHelper = new DBHelper(context);
    SQLiteDatabase db = dbHelper.getReadableDatabase();

    try {

        db.execSQL("DELETE FROM " + DBHelper.TABLE_CART);

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

}

}

使用法

  if(Database.Cart.isCartAvailable(context)){

       Database.deleteCart(context);

   }
4

書くだけ

SQLiteDatabase db = this.getWritableDatabase();
db.execSQL("delete from "+TableName);

または

db.delete(tablename,null,null);
4
Enamul Haque

最後の2つのnullパラメータでSqliteの削除関数を使用します。

db.delete(TABLE_NAME,null,null)
3
user4329916
//Delete all records of table
db.execSQL("DELETE FROM " + TABLE_NAME);

//Reset the auto_increment primary key if you needed
db.execSQL("UPDATE SQLITE_SEQUENCE SET SEQ=0 WHERE NAME=" + TABLE_NAME);

//For go back free space by shrinking sqlite file
db.execSQL("VACUUM");
2
Nabi K.A.Z.
    getContentResolver().delete(DB.TableName.CONTENT_URI, null, null);
1
fvolodimir

これは私のために働くでしょう。 execSQLとrawQueryの違いはここにあります。 rawQueryは検索ケースで最も使用され、execSQLは主に適用操作で使用されます。

   // truncate the table
    ArrayList<HashMap<String, String>> getDatabaseName1(String sr) {
        SQLiteDatabase sqLiteDatabase=this.getWritableDatabase();
        sqLiteDatabase.execSQL("delete from Hotel");
        sqLiteDatabase.close();
        return null;
    }
1
Pooja Kumari

役に立つ場合があります

public boolean deleteAllFood() {
            SQLiteDatabase db = dbHelper.getReadableDatabase();
            int affectedRows = db.delete(DBHelper.TABLE_NAME_FOOD, null, null);
            return affectedRows > 0;
        }



public class DBProgram {
    private static DBProgram INSTANCE;
    private Context context;
    private DBHelper dbHelper;

    private DBProgram(Context context) {
        // burda bu methodu kullanan activity ile eileştiriyoruz
        this.dbHelper = new DBHelper(context);
    }

    public static synchronized DBProgram getInstance(Context context) {
        if (INSTANCE == null) {
            INSTANCE = new DBProgram(context);
        }
        return INSTANCE;
    }

    //**********************************************
    public boolean updateById(ProgramModel program) {
        SQLiteDatabase database = dbHelper.getWritableDatabase();
        ContentValues contentValues = new ContentValues();
        contentValues.put(DBHelper.COLUM_NAME_P, program.getProgName());
        contentValues.put(DBHelper.COLUM_DAY_P, program.getDay());
        contentValues.put(DBHelper.COLUMN_WEIGHT_P, program.getWeight());
        contentValues.put(DBHelper.COLUMN_SET_P, program.getSet());
        contentValues.put(DBHelper.COLUMN_REPETITION_P, program.getRepetition());
        int affectedRows = database.update(DBHelper.TABLE_NAME_PROGRAM, contentValues, "PROG_ID_P = ?", new String[]{String.valueOf(program.getId())});
        return affectedRows > 0;
    }
    //**********************************************


    //**********************************************
    // TODO
    public boolean deleteProgramById(int id) {
        SQLiteDatabase database = dbHelper.getReadableDatabase();
        int affectedRows = database.delete(DBHelper.TABLE_NAME_PROGRAM, DBHelper.COLUMN_ID_P + "= ?", new String[]{String.valueOf(id)});
        // return bize etkilenen sıra sayısınıını temsil eder
        return affectedRows > 0;
    }
    //**********************************************


    //***************************************************
    public boolean deleteProgramByName(String progName) {
        SQLiteDatabase database = dbHelper.getReadableDatabase();
        final String whereClause = DBHelper.COLUM_NAME_P + "=?";
        final String whereArgs[] = {progName};
        int affectedRows = database.delete(DBHelper.TABLE_NAME_PROGRAM, whereClause, whereArgs);
        return affectedRows > 0;
    }
    //***************************************************


    //************************************** get Meal
    // TODO  WEB Get All  Meals
    public List<ProgramModel> getAllProgram(String name) {
        List<ProgramModel> foodList = new ArrayList<>();
        ProgramModel food;
        SQLiteDatabase database = dbHelper.getReadableDatabase();
        final String kolonlar[] = {DBHelper.COLUMN_ID_P,
                DBHelper.COLUM_NAME_P,
                DBHelper.COLUM_DAY_P,
                DBHelper.COLUMN_WEIGHT_P,
                DBHelper.COLUMN_SET_P,
                DBHelper.COLUMN_REPETITION_P};

        final String whereClause = DBHelper.COLUM_DAY_P + "=?";
        final String whereArgs[] = {name};
        Cursor cursor = database.query(DBHelper.TABLE_NAME_PROGRAM, kolonlar, whereClause, whereArgs, null, null, null);
        while (cursor.moveToNext()) {

            food = new ProgramModel();
            food.setId(cursor.getInt(cursor.getColumnIndex(DBHelper.COLUMN_ID_P)));
            food.setProgName(cursor.getString(cursor.getColumnIndex(DBHelper.COLUM_NAME_P)));
            food.setDay(cursor.getString(cursor.getColumnIndex(DBHelper.COLUM_DAY_P)));
            food.setWeight(cursor.getInt(cursor.getColumnIndex(DBHelper.COLUMN_WEIGHT_P)));
            food.setSet(cursor.getInt(cursor.getColumnIndex(DBHelper.COLUMN_SET_P)));
            food.setRepetition(cursor.getInt(cursor.getColumnIndex(DBHelper.COLUMN_REPETITION_P)));
            foodList.add(food);
        }
        database.close();
        cursor.close();
        return foodList;
    }
    //**************************************


    //**************************************insert FOOD
    //TODO LOCAL insert Foods
    public boolean insertProgram(ProgramModel favorite) {
        boolean result = false;
        ContentValues contentValues = new ContentValues();
        contentValues.put(DBHelper.COLUM_NAME_P, favorite.getProgName());
        contentValues.put(DBHelper.COLUM_DAY_P, favorite.getDay());
        contentValues.put(DBHelper.COLUMN_WEIGHT_P, favorite.getWeight());
        contentValues.put(DBHelper.COLUMN_SET_P, favorite.getSet());
        contentValues.put(DBHelper.COLUMN_REPETITION_P, favorite.getRepetition());
        SQLiteDatabase database = dbHelper.getWritableDatabase();
        long id = database.insert(DBHelper.TABLE_NAME_PROGRAM, null, contentValues);
        if (id != 1) {
            result = true;
        }
        database.close();

        return result;
    }
    //***************************************************

    // *******************************  SQLITE HELPER CLASS ******************
    private class DBHelper extends SQLiteOpenHelper {
        private final Context context;
        private static final String DATABASE_NAME = "PROGRAM_INFO";
        private static final String TABLE_NAME_PROGRAM = "PROGRAM";
        private static final int DATABASE_VERSION = 2;

        // FOOD
        private static final String COLUMN_ID_P = "PROG_ID_P";
        private static final String COLUM_NAME_P = "PROG_NAME_P";
        private static final String COLUM_DAY_P = "PROG_DAY_P";
        private static final String COLUMN_WEIGHT_P = "PROG_WEIGHT_P";
        private static final String COLUMN_SET_P = "PROG_SET_P";
        private static final String COLUMN_REPETITION_P = "PROG_REPETITION_P";

        private final String CREATE_TABLE_PROGRAM = "CREATE TABLE " + TABLE_NAME_PROGRAM +
                " (" + COLUMN_ID_P + " INTEGER PRIMARY KEY AUTOINCREMENT, "
                + COLUM_NAME_P + " TEXT, "
                + COLUM_DAY_P + " TEXT, "
                + COLUMN_WEIGHT_P + " INTEGER, "
                + COLUMN_SET_P + " INTEGER, "
                + COLUMN_REPETITION_P + " INTEGER)";

        private static final String DROP_TABLE_PROGRAM = "DROP TABLE IF EXIST " + TABLE_NAME_PROGRAM;

        public DBHelper(Context context) {
            super(context, DATABASE_NAME, null, DATABASE_VERSION);
            this.context = context;
        }

        @Override
        public void onCreate(SQLiteDatabase db) {
            db.execSQL(CREATE_TABLE_PROGRAM);

            Util.showMessage(context, "Database Created");
        }

        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            db.execSQL(DROP_TABLE_PROGRAM);
            Util.showMessage(context, "Database Upgrated");
            onCreate(db);
        }

        @Override
        public void onDowngrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            super.onDowngrade(db, oldVersion, newVersion);
        }
    }


}
0
Sam

この方法は、データベースからすべてのデータを遅らせます

 public void deleteAll()
{
    SQLiteDatabase db = this.getWritableDatabase();
    db.execSQL("delete from "+ TABLE_NAME);
    db.close();
}