I am new to Android and need to display Starttime, Stoptime and Name in a Listview. For displaying I use a SimpleAdapter. The problem is that I have two SQLite tables:
Table time: Starttime | Stoptime | Student ID
Table student: Student ID | Student name
Right now, I use a Cursor to get Starttime, Stoptime and Student ID from my database
Cursor curm1 = myDb.getAllMonday();
while (curm1.moveToNext()) {
final HashMap<String, String> resultMapMonday = new HashMap<>();
resultMapMonday.put("Start", curm1.getString(3));
resultMapMonday.put("Stop", curm1.getString(4));
resultMapMonday.put("Student", curm1.getString(5));
arrayListStudentsName.add(curm1.getString(5));
listItemsMo.add(resultMapMonday);
}
and then a SimpleAdapter to display it:
final SimpleAdapter adaptersimpleMo = new SimpleAdapter(this, listItemsMo, R.layout.timeslots_configurate,
new String[]{"Start", "Stop", "Student"},
new int[]{R.id.oneTime_start, R.id.oneTime_stop, R.id.selectedStudent});
But instead of the id, I want to display the names, which are stored in the other table. I can get the matching names of the Ids with another cursor
Cursor curm2 = myDb.getNamesbyIDs(arrayListStudentsName);
while (curm2.moveToNext()) {
final HashMap<String, String> resultMapNames = new HashMap<>();
resultMapNames.put("Name", curm2.getString(1));
}
But I don't know how to get the names in the same adapter to display the names in the same list Item as the matching start & stop time.
EDIT
public Cursor getAllMonday() {
SQLiteDatabase db = this.getWritableDatabase();
Cursor res = db.rawQuery("SELECT * FROM " + TABLE_TIME + " WHERE day = 'Montag' ORDER BY CAST(start as unsigned)", null);
return res;
}
Change getAllMonday()
to use a query that joins the 2 tables:
public Cursor getAllMonday() {
SQLiteDatabase db = this.getWritableDatabase();
String sql = "SELECT t.Start, t.Stop, s.Studentname FROM " + TABLE_TIME + " AS t INNER JOIN " + TABLE_STUDENT +
" AS s ON s.StudentID = t.StudentID WHERE t.day = 'Montag' ORDER BY CAST(t.start as unsigned)"
Cursor res = db.rawQuery(sql, null);
return res;
}
Change the table variable TABLE_STUDENT
and the column names that I used to the actual ones.
Now the cursor contains the name of the student and not the id.
Next change the code to:
Cursor curm1 = myDb.getAllMonday();
while (curm1.moveToNext()) {
final HashMap<String, String> resultMapMonday = new HashMap<>();
resultMapMonday.put("Start", curm1.getString(curm1.getColumnIndex("Start")));
resultMapMonday.put("Stop", curm1.getString(curm1.getColumnIndex("Stop")));
resultMapMonday.put("Student", curm1.getString(curm1.getColumnIndex("Studentname")));
arrayListStudentsName.add(curm1.getString(curm1.getColumnIndex("Studentname")));
listItemsMo.add(resultMapMonday);
}
curm1.close();