android how can i change the getdata method to input it into the listView

public String getData(){ String [] columns= new String[]{ KEY_ROWID,KEY_USERNAME,KEY_AGE,KEY_ClINIC,KEY_PHONE,KEY_EMAIL,KEY_DATESIGNUP ,KEY_CONDITIONID,KEY_DOCTORID,KEY_LOGINID,KEY_ACTIVITYNAME,KEY_NOTIFICATIONNAME,KEY_GROUPNAME,KEY_APPROVED }; Cursor c= ourdatabase.query(DATABASE_TABLES, columns, null,null, null, null, null); String result="";

    int iRow=c.getColumnIndex(KEY_ROWID);
    int iUserName=c.getColumnIndex(KEY_USERNAME);
    int iAge=c.getColumnIndex(KEY_AGE);
    int iClinic=c.getColumnIndex(KEY_ClINIC);
    int iPhone=c.getColumnIndex(KEY_PHONE);
    int iEmail=c.getColumnIndex(KEY_EMAIL);
    int iDateSignup=c.getColumnIndex(KEY_DATESIGNUP);
    int iConditionID=c.getColumnIndex(KEY_CONDITIONID);
    int iDoctorID=c.getColumnIndex(KEY_DOCTORID);
    int iLoginID=c.getColumnIndex(KEY_LOGINID);
    int iActivityName=c.getColumnIndex(KEY_ACTIVITYNAME);
    int iNotificationName=c.getColumnIndex(KEY_NOTIFICATIONNAME);
    int iGroupName=c.getColumnIndex(KEY_GROUPNAME);
    int iApproved=c.getColumnIndex(KEY_APPROVED);

    for(c.moveToLast();!c.isAfterLast();c.moveToNext()){

    //how can i change below here?

        result= result+c.getString(iRow)+" "+c.getString(iUserName)+" "+c.getString(iAge)+" "+c.getString(iClinic)+" "
    +c.getString(iPhone)+" "+c.getString(iEmail)+" "+c.getString(iDateSignup)+" "+c.getString(iConditionID)+" "+c.getString(iDoctorID)
    +" "+c.getString(iLoginID)+" "+c.getString(iActivityName)+" "+c.getString(iNotificationName)+" "+c.getString(iGroupName)+" "+c.getString(iApproved)+"\n";

    }

    return result;

}