Get ID from database onClick ListView

Question

I'm using SQLite in my app. I have a listView which is populated with values from the database.

When I click on an item from the listview, I go to another page, and I would like ( with an intent), to transfer the ID FROM THE DATABASE. The problem is that I'm only transfering the ID from the position of my listView, which is wrong. For example, let's say I have :

ID Name 1 David 2 Joseph

My listView will display both names. But if I delete David, the ID i'm getting when i click in Joseph is 1 and not 2 . And that's the problem !

So : I want to retrieve the ID from my database and not from my listView when I click on an item

Here's my method in my helper : UPDATED !

   public Cursor getAllCours()
{
    String Query = ("select ID as _id, nom from " + TABLE_COURS);
    Open();
    Cursor cursor = db.rawQuery(Query, null);
       return cursor;
}

And how I display it in my Activity :

  Cursor cursor = dbhelper.getAllCours();
    String[] from = { "nom" }; int[] to = { android.R.id.text1 };
    SimpleCursorAdapter adapter = new SimpleCursorAdapter(this, android.R.layout.simple_list_item_1, cursor, from, to, 0);
    lv.setAdapter(adapter);

And finally, my listviewClickListener :

  lv.setOnItemClickListener(new AdapterView.OnItemClickListener()
    {

        @Override
        public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {

            //I THINK THE ERROR IS HERE !
            long itemid= lv.getItemIdAtPosition(i);
            int id= (int)itemid;
            String a =lv.getItemAtPosition(i).toString();
            Intent b = new Intent(AffichageCours.this,AffichageNotes.class);
            Bundle args = new Bundle();
            args.putString("nom_cours",a);
            args.putInt("id",id);
            b.putExtras(args);
            startActivity(b);
        }

    });
}

My TABLE_COURS columns:

 private static final String TABLE_COURS = "cours";
private static final String COLONNE_IDCOURS = "ID";
private static final String COLONNE_COURS = "nom";

 private static final String CREATE_COURS ="CREATE TABLE cours " +
        "("+COLONNE_IDCOURS+" INTEGER PRIMARY KEY AUTOINCREMENT , "
        +COLONNE_COURS+" TEXT NOT NULL)";

How i delete with my Context Menu :

 @Override
public boolean onContextItemSelected(MenuItem item) {
    AdapterView.AdapterContextMenuInfo info = (AdapterView.AdapterContextMenuInfo) item.getMenuInfo();
    switch(item.getItemId())
    {
        case R.id.supprimer:
            dbhelper.deleteCours(lv.getItemAtPosition(info.position).toString());
            adapter.remove(adapter.getItem(info.position)); //the error is here..
            adapter.notifyDataSetChanged();
            return true;

Thank you guys !

Answer 1

I think the problem is that you are asking for the Id of the row in the ListView not the actual data that row is holding up. In the onItemClick method change this:

long itemid= lv.getItemIdAtPosition(i);

For this:

String courId = adapter.getItem(i);

The key here is to try to get the data from the ArrayAdapter not directly from the ListView.

Answer 2

You should have use Java Objects so it will be easy for you.

Suppost you have stored Contacts in dataBase(contains fields: Name, Mobile and Address). So create a POJO for that:

class Contacts{
    private String name;
    private String mobile;
    private String address;

    //write getters and setters
}

Then, whenever you are accessing database fetch all contacts you want to show and store in ArrayList<Contacts> mContactList;

And then pass this list in your ListView's adapter to show data in listView.

CustomAdapter adapter = new CustomAdapter(context, layoutResource, mContactList);

Then you can retrieve the object on clicking a particular list item on the basis of position;

lv.setOnItemClickListener(new AdapterView.OnItemClickListener()
    {

        @Override
        public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
           Contacts contact = mContactList.get(i);
           // now you can do whatever you want;
        }

    });

Answer 3

Since you are not using a custom adapter, why dont you try this inside onItemClickListener

String idThatYouWant = listeCours.get(i).getId();