将游标显示为方法的返回值-SQLite

Question

我正在尝试使用以下方法来计算我的数据库中某一列中所有值的总和。

/**
     * Method that gives the the total of all
     * Average Meditation levels in the DB
     * @return
     */
    public Cursor getTotalOfAllMedLevels(){

        SQLiteDatabase db = this.getWritableDatabase();

        String query = "SELECT SUM(avgmeditation) FROM " + TABLE_SCORE;


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

        return c;



    }

然后我尝试在不同的 Activity 中显示 TextView (avgMed) 中方法的返回值，如下所示：

public void displayAverageOfAllMedValues() {

        Cursor c = db.getTotalOfAllMedLevels();

        avgMed.setText("" + c);

    }

但是在TextView中得到如下输出：

android.database.sqlite.SQLiteCursor@529db063

有没有办法将此输出转换为 int 值，或者如何更改我的代码以提供我想要的 Int 输出。

编辑：当前数据库的创建和结构：

public class DatabaseHelper extends SQLiteOpenHelper {

    // Database Version
    private static final int DATABASE_VERSION = 10;

    // Database Name
    private final static String DATABASE_NAME = "MeditationDatabase";

    // Contacts table name
    private static final String TABLE_SCORE = "scores";

    // Contacts Table Columns names
    private static final String COL_SESSION = "sessionid";
    private static final String COL_GAMETITLE = "game";
    private static final String COL_NAME = "name";
    private static final String COL_MED = "avgmeditation";
    private static final String COL_MAX = "maxmeditation";
    private static final String COL_AVGATT = "avgattention";
    private static final String COL_MAXATT = "maxattention";
    private static final String COL_SCORE = "score";
    private static final String COL_DATE = "date";

    /**
     * Constructor
     * 
     * @param context
     */
    public DatabaseHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }

    /**
     * Method that creates the database
     */
    @Override
    public void onCreate(SQLiteDatabase db) {



        String CREATE_TABLE_SCORE = "CREATE TABLE " + TABLE_SCORE + "(" + COL_SESSION
                + " STRING PRIMARY KEY, " + COL_GAMETITLE + " STRING, "  + COL_NAME + " STRING, " + COL_MED + " INTEGER, "
                 + COL_MAX + " INTEGER, " + COL_AVGATT + " INTEGER, " + COL_MAXATT + " INTEGER, "  + COL_SCORE +  " INTEGER, " + COL_DATE + " STRING " + ")";
        db.execSQL(CREATE_TABLE_SCORE);

    }

Answer 1

游标就像一个数组，其中包含您选择的所有对象。你必须这样做：

public void displayAverageOfAllMedValues() {

    Cursor c = db.getTotalOfAllMedLevels();

    if( c != null && c.moveToFirst )
    {

         avgMed.setText("" + c.getInt( 0 ) );

    }

}