Question

我必须在我的数据库训练和练习中使用以下方法getAllWorkouts和getAllExercises。对，这些方法分别进行锻炼和练习。我如何将这两者结合在一起？所以训练将使所有练习加入其中。这是1：M的关系。

getAllWorkouts

  public ArrayList<Workout> getAllWokouts(){
    ArrayList<Workout> workoutArrayList = new ArrayList<Workout>();
    SQLiteDatabase db = this.getReadableDatabase();

    try{
        String selectQuery = "SELECT * FROM " + TABLE_WORKOUT;
        db = this.getReadableDatabase();
        Cursor c = db.rawQuery(selectQuery, null);

        if (c != null && c.moveToFirst()){
            do {
                Workout workout = new Workout();
                workout.setId(c.getInt(0));
                workout.setName(c.getString(1));

                workoutArrayList.add(workout);


            } while (c.moveToNext());
        }

        return workoutArrayList;
} catch (SQLiteException se){
        Log.v("Exception",
                Log.getStackTraceString(se));

    } catch (Exception e){
    Log.v("Exception",
            Log.getStackTraceString(e));
    } finally {
        db.close();
    }
    return workoutArrayList;
    }

getAllExercises

ArrayList<Exercise> exerciseArrayList = new ArrayList<Exercise>();
    SQLiteDatabase db = this.getReadableDatabase();

    try{
        String selectQuery = "SELECT * FROM " + TABLE_EXERCISE;
        Cursor cursor = db.rawQuery(selectQuery, null);
        if (cursor != null && cursor.moveToFirst()){
            do {
                Exercise exercise = new Exercise();
                exercise.setId(cursor.getInt(0));
                exercise.setName(cursor.getString(1));
                exercise.setSet(cursor.getString(2));
                exercise.setWeight(cursor.getString(3));
                exercise.setReps(cursor.getString(4));

                exerciseArrayList.add(exercise);
            } while (cursor.moveToNext());
        }
        return exerciseArrayList;
    } catch (SQLiteException se){
        Log.v("Exception",
                Log.getStackTraceString(se));

    } catch (Exception e){
        Log.v("Exception",
                Log.getStackTraceString(e));
    } finally {
        db.close();
    }
        return exerciseArrayList;
    }

我使用了以下代码

public Cursor getAllWorkoutsExercises(){

    SQLiteDatabase db = this.getReadableDatabase();

    String SELECT_QUERY = "SELECT * FROM '" + TABLE_WORKOUT  + "'JOIN'" + TABLE_EXERCISE +  "' ON '" + EXERCISE_ID  + "' GROUP BY '" + EXERCISE_ID + "'ORDER BY'" + WORKOUT_NAME;   
    Cursor mCursor = db.rawQuery(SELECT_QUERY, null);

    return mCursor;
}

Answer 1

试试这个： Cursor mCursor = db.rawQuery("SELECT * FROM Table1, Table2 " + "WHERE Table1.id = Table2.id_table1 " + "GROUP BY Table1.data1", null);

从多个表中选择？

1 个答案: