Base de données Android SQLite et fournisseurs de contenu

Cursor cursor = getReadableDatabase().
   rawQuery("select * from todo where _id = ?", new String[] { id });

return database.query(DATABASE_TABLE, 
   new String[] { KEY_ROWID, KEY_CATEGORY, KEY_SUMMARY,    
   KEY_DESCRIPTION }, null, null, null, null, null);

package de.vogella.android.sqlite.first;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

public class MySQLiteHelper extends SQLiteOpenHelper {

  public static final String TABLE_COMMENTS = "comments";
  public static final String COLUMN_ID = "_id";
  public static final String COLUMN_COMMENT = "comment";

  private static final String DATABASE_NAME = "commments.db";
  private static final int DATABASE_VERSION = 1;

  // Commande sql pour la création de la base de données
  private static final String DATABASE_CREATE = "create table "
      + TABLE_COMMENTS + "(" + COLUMN_ID
      + " integer primary key autoincrement, " + COLUMN_COMMENT
      + " text not null);";

  public MySQLiteHelper(Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
  }

  @Override
  public void onCreate(SQLiteDatabase database) {
    database.execSQL(DATABASE_CREATE);
  }

  @Override
  public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    Log.w(MySQLiteHelper.class.getName(),
        "Upgrading database from version " + oldVersion + " to "
            + newVersion + ", which will destroy all old data");
    db.execSQL("DROP TABLE IF EXISTS " + TABLE_COMMENTS);
    onCreate(db);
  }
}

package de.vogella.android.sqlite.first;

public class Comment {
  private long id;
  private String comment;

  public long getId() {
    return id;
  }

  public void setId(long id) {
    this.id = id;
  }

  public String getComment() {
    return comment;
  }

  public void setComment(String comment) {
    this.comment = comment;
  }

  // Sera utilisée par ArrayAdapter dans la ListView
  @Override
  public String toString() {
    return comment;
  }
}

package de.vogella.android.sqlite.first;

import java.util.ArrayList;
import java.util.List;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;

public class CommentsDataSource {

  // Champs de la base de données
  private SQLiteDatabase database;
  private MySQLiteHelper dbHelper;
  private String[] allColumns = { MySQLiteHelper.COLUMN_ID,
      MySQLiteHelper.COLUMN_COMMENT };

  public CommentsDataSource(Context context) {
    dbHelper = new MySQLiteHelper(context);
  }

  public void open() throws SQLException {
    database = dbHelper.getWritableDatabase();
  }

  public void close() {
    dbHelper.close();
  }

  public Comment createComment(String comment) {
    ContentValues values = new ContentValues();
    values.put(MySQLiteHelper.COLUMN_COMMENT, comment);
    long insertId = database.insert(MySQLiteHelper.TABLE_COMMENTS, null,
        values);
    Cursor cursor = database.query(MySQLiteHelper.TABLE_COMMENTS,
        allColumns, MySQLiteHelper.COLUMN_ID + " = " + insertId, null,
        null, null, null);
    cursor.moveToFirst();
    Comment newComment = cursorToComment(cursor);
    cursor.close();
    return newComment;
  }

  public void deleteComment(Comment comment) {
    long id = comment.getId();
    System.out.println("Comment deleted with id: " + id);
    database.delete(MySQLiteHelper.TABLE_COMMENTS, MySQLiteHelper.COLUMN_ID
        + " = " + id, null);
  }

  public List<Comment> getAllComments() {
    List<Comment> comments = new ArrayList<Comment>();

    Cursor cursor = database.query(MySQLiteHelper.TABLE_COMMENTS,
        allColumns, null, null, null, null, null);

    cursor.moveToFirst();
    while (!cursor.isAfterLast()) {
      Comment comment = cursorToComment(cursor);
      comments.add(comment);
      cursor.moveToNext();
    }
    // assurez-vous de la fermeture du curseur
    cursor.close();
    return comments;
  }

  private Comment cursorToComment(Cursor cursor) {
    Comment comment = new Comment();
    comment.setId(cursor.getLong(0));
    comment.setComment(cursor.getString(1));
    return comment;
  }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <LinearLayout
        android:id="@+id/group"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" >

        <Button
            android:id="@+id/add"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Add New" 
            android:onClick="onClick"/>

        <Button
            android:id="@+id/delete"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Delete First" 
            android:onClick="onClick"/>
        
    </LinearLayout>

    <ListView
        android:id="@android:id/list"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello" />

</LinearLayout>

package de.vogella.android.sqlite.first;

import java.util.List;
import java.util.Random;

import android.app.ListActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.ArrayAdapter;

public class TestDatabaseActivity extends ListActivity {
  private CommentsDataSource datasource;

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    datasource = new CommentsDataSource(this);
    datasource.open();

    List<Comment> values = datasource.getAllComments();

    // utilisez SimpleCursorAdapter pour afficher les
    // éléments dans une ListView
    ArrayAdapter<Comment> adapter = new ArrayAdapter<Comment>(this,
        android.R.layout.simple_list_item_1, values);
    setListAdapter(adapter);
  }

  // Sera appelée par l'attribut onClick 
  // des boutons déclarés dans main.xml
  public void onClick(View view) {
    @SuppressWarnings("unchecked")
    ArrayAdapter<Comment> adapter = (ArrayAdapter<Comment>) getListAdapter();
    Comment comment = null;
    switch (view.getId()) {
    case R.id.add:
      String[] comments = new String[] { "Cool", "Very nice", "Hate it" };
      int nextInt = new Random().nextInt(3);
      // enregistrer le nouveau commentaire dans la base de données
      comment = datasource.createComment(comments[nextInt]);
      adapter.add(comment);
      break;
    case R.id.delete:
      if (getListAdapter().getCount() > 0) {
        comment = (Comment) getListAdapter().getItem(0);
        datasource.deleteComment(comment);
        adapter.remove(comment);
      }
      break;
    }
    adapter.notifyDataSetChanged();
  }

  @Override
  protected void onResume() {
    datasource.open();
    super.onResume();
  }

  @Override
  protected void onPause() {
    datasource.close();
    super.onPause();
  }
}

<provider
       android:authorities="de.vogella.android.todos.contentprovider"
       android:name=".contentprovider.MyTodoContentProvider" >
</provider>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/contactview"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</LinearLayout>

package de.vogella.android.contentprovider;

import android.app.Activity;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.provider.ContactsContract;
import android.widget.TextView;

public class ContactsActivity extends Activity {
  
/** Appelée quand l'activité est créée pour la première fois */

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_contacts);
    TextView contactView = (TextView) findViewById(R.id.contactview);

    Cursor cursor = getContacts();

    while (cursor.moveToNext()) {

      String displayName = cursor.getString(cursor
          .getColumnIndex(ContactsContract.Data.DISPLAY_NAME));
      contactView.append("Name: ");
      contactView.append(displayName);
      contactView.append("\n");
    }
  }

  private Cursor getContacts() {
    // Exécuter la requête
    Uri uri = ContactsContract.Contacts.CONTENT_URI;
    String[] projection = new String[] { ContactsContract.Contacts._ID,
        ContactsContract.Contacts.DISPLAY_NAME };
    String selection = ContactsContract.Contacts.IN_VISIBLE_GROUP + " = '"
        + ("1") + "'";
    String[] selectionArgs = null;
    String sortOrder = ContactsContract.Contacts.DISPLAY_NAME
        + " COLLATE LOCALIZED ASC";
    
    return managedQuery(uri, projection, selection, selectionArgs,
        sortOrder);
  }
}

# start a new loader or re-connect to existing one
getLoaderManager().initLoader(0, null, this);

package de.vogella.android.todos.database;

import android.database.sqlite.SQLiteDatabase;
import android.util.Log;

public class TodoTable {

  // Table de la base de données
  public static final String TABLE_TODO = "todo";
  public static final String COLUMN_ID = "_id";
  public static final String COLUMN_CATEGORY = "category";
  public static final String COLUMN_SUMMARY = "summary";
  public static final String COLUMN_DESCRIPTION = "description";

  // Instruction SQL de création de la base de données
  private static final String DATABASE_CREATE = "create table " 
      + TABLE_TODO
      + "(" 
      + COLUMN_ID + " integer primary key autoincrement, " 
      + COLUMN_CATEGORY + " text not null, " 
      + COLUMN_SUMMARY + " text not null," 
      + COLUMN_DESCRIPTION
      + " text not null" 
      + ");";

  public static void onCreate(SQLiteDatabase database) {
    database.execSQL(DATABASE_CREATE);
  }

  public static void onUpgrade(SQLiteDatabase database, int oldVersion,
      int newVersion) {
    Log.w(TodoTable.class.getName(), "Upgrading database from version "
        + oldVersion + " to " + newVersion
        + ", which will destroy all old data");
    database.execSQL("DROP TABLE IF EXISTS " + TABLE_TODO);
    onCreate(database);
  }
}

package de.vogella.android.todos.database;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class TodoDatabaseHelper extends SQLiteOpenHelper {

  private static final String DATABASE_NAME = "todotable.db";
  private static final int DATABASE_VERSION = 1;

  public TodoDatabaseHelper(Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
  }

  // Méthode appelée pendant la création de la base de données
  @Override
  public void onCreate(SQLiteDatabase database) {
    TodoTable.onCreate(database);
  }

  // Méthode appelée pendant une mise a jour de la base de  
  // données, par exemple vous augmentez sa version 
  @Override
  public void onUpgrade(SQLiteDatabase database, int oldVersion,
      int newVersion) {
    TodoTable.onUpgrade(database, oldVersion, newVersion);
  }
}

package de.vogella.android.todos.contentprovider;

import java.util.Arrays;
import java.util.HashSet;

import android.content.ContentProvider;
import android.content.ContentResolver;
import android.content.ContentValues;
import android.content.UriMatcher;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteQueryBuilder;
import android.net.Uri;
import android.text.TextUtils;
import de.vogella.android.todos.database.TodoDatabaseHelper;
import de.vogella.android.todos.database.TodoTable;

public class MyTodoContentProvider extends ContentProvider {

  // base de données
  private TodoDatabaseHelper database;

  // utilisées pour UriMatcher
  private static final int TODOS = 10;
  private static final int TODO_ID = 20;

  private static final String AUTHORITY = "de.vogella.android.todos.contentprovider";

  private static final String BASE_PATH = "todos";
  public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY
      + "/" + BASE_PATH);

  public static final String CONTENT_TYPE = ContentResolver.CURSOR_DIR_BASE_TYPE
      + "/todos";
  public static final String CONTENT_ITEM_TYPE = ContentResolver.CURSOR_ITEM_BASE_TYPE
      + "/todo";

  private static final UriMatcher sURIMatcher = new UriMatcher(UriMatcher.NO_MATCH);
  static {
    sURIMatcher.addURI(AUTHORITY, BASE_PATH, TODOS);
    sURIMatcher.addURI(AUTHORITY, BASE_PATH + "/#", TODO_ID);
  }

  @Override
  public boolean onCreate() {
    database = new TodoDatabaseHelper(getContext());
    return false;
  }

  @Override
  public Cursor query(Uri uri, String[] projection, String selection,
      String[] selectionArgs, String sortOrder) {

    // Utiliser SQLiteQueryBuilder à la place de la méthode query()
    SQLiteQueryBuilder queryBuilder = new SQLiteQueryBuilder();

    // vérifier si l'appelant a demandé une colonne qui n'existe pas
    checkColumns(projection);

    // Préciser la table
    queryBuilder.setTables(TodoTable.TABLE_TODO);

    int uriType = sURIMatcher.match(uri);
    switch (uriType) {
    case TODOS:
      break;
    case TODO_ID:
      // ajouter l'ID à la requête d'origine
      queryBuilder.appendWhere(TodoTable.COLUMN_ID + "="
          + uri.getLastPathSegment());
      break;
    default:
      throw new IllegalArgumentException("Unknown URI: " + uri);
    }

    SQLiteDatabase db = database.getWritableDatabase();
    Cursor cursor = queryBuilder.query(db, projection, selection,
        selectionArgs, null, null, sortOrder);
    // assurez-vous que les écouteurs potentiels seront notifiés
    cursor.setNotificationUri(getContext().getContentResolver(), uri);

    return cursor;
  }

  @Override
  public String getType(Uri uri) {
    return null;
  }

  @Override
  public Uri insert(Uri uri, ContentValues values) {
    int uriType = sURIMatcher.match(uri);
    SQLiteDatabase sqlDB = database.getWritableDatabase();
    int rowsDeleted = 0;
    long id = 0;
    switch (uriType) {
    case TODOS:
      id = sqlDB.insert(TodoTable.TABLE_TODO, null, values);
      break;
    default:
      throw new IllegalArgumentException("Unknown URI: " + uri);
    }
    getContext().getContentResolver().notifyChange(uri, null);
    return Uri.parse(BASE_PATH + "/" + id);
  }

  @Override
  public int delete(Uri uri, String selection, String[] selectionArgs) {
    int uriType = sURIMatcher.match(uri);
    SQLiteDatabase sqlDB = database.getWritableDatabase();
    int rowsDeleted = 0;
    switch (uriType) {
    case TODOS:
      rowsDeleted = sqlDB.delete(TodoTable.TABLE_TODO, selection,
          selectionArgs);
      break;
    case TODO_ID:
      String id = uri.getLastPathSegment();
      if (TextUtils.isEmpty(selection)) {
        rowsDeleted = sqlDB.delete(TodoTable.TABLE_TODO,
            TodoTable.COLUMN_ID + "=" + id, 
            null);
      } else {
        rowsDeleted = sqlDB.delete(TodoTable.TABLE_TODO,
            TodoTable.COLUMN_ID + "=" + id 
            + " and " + selection,
            selectionArgs);
      }
      break;
    default:
      throw new IllegalArgumentException("Unknown URI: " + uri);
    }
    getContext().getContentResolver().notifyChange(uri, null);
    return rowsDeleted;
  }

  @Override
  public int update(Uri uri, ContentValues values, String selection,
      String[] selectionArgs) {

    int uriType = sURIMatcher.match(uri);
    SQLiteDatabase sqlDB = database.getWritableDatabase();
    int rowsUpdated = 0;
    switch (uriType) {
    case TODOS:
      rowsUpdated = sqlDB.update(TodoTable.TABLE_TODO, 
          values, 
          selection,
          selectionArgs);
      break;
    case TODO_ID:
      String id = uri.getLastPathSegment();
      if (TextUtils.isEmpty(selection)) {
        rowsUpdated = sqlDB.update(TodoTable.TABLE_TODO, 
            values,
            TodoTable.COLUMN_ID + "=" + id, 
            null);
      } else {
        rowsUpdated = sqlDB.update(TodoTable.TABLE_TODO, 
            values,
            TodoTable.COLUMN_ID + "=" + id 
            + " and " 
            + selection,
            selectionArgs);
      }
      break;
    default:
      throw new IllegalArgumentException("Unknown URI: " + uri);
    }
    getContext().getContentResolver().notifyChange(uri, null);
    return rowsUpdated;
  }

  private void checkColumns(String[] projection) {
    String[] available = { TodoTable.COLUMN_CATEGORY,
        TodoTable.COLUMN_SUMMARY, TodoTable.COLUMN_DESCRIPTION,
        TodoTable.COLUMN_ID };
    if (projection != null) {
      HashSet<String> requestedColumns = new HashSet<String>(Arrays.asList(projection));
      HashSet<String> availableColumns = new HashSet<String>(Arrays.asList(available));
      // vérifier si toutes les colonnes demandées sont disponibles
      if (!availableColumns.containsAll(requestedColumns)) {
        throw new IllegalArgumentException("Unknown columns in projection");
      }
    }
  }
}

<application
  <!-- Place the following after the Activity
       Definition
  -->
  <provider
      android:name=".contentprovider.MyTodoContentProvider"
      android:authorities="de.vogella.android.todos.contentprovider" >
   </provider>
</application>

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">

    <item
        android:id="@+id/insert"
        android:showAsAction="always"
        android:title="Insert">
    </item>

</menu>

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string-array name="priorities">
        <item>Urgent</item>
        <item>Reminder</item>
    </string-array>

</resources>

<?xml version="1.0" encoding="utf-8"?>
<resources>
  <string name="hello">Hello World, Todo!</string>
  <string name="app_name">Todo</string>
  <string name="no_todos">Currently there are no Todo items maintained</string>
  <string name="menu_insert">Add Item</string>
  <string name="menu_delete">Delete Todo</string>
  <string name="todo_summary">Summary</string>
  <string name="todo_description">Delete Todo</string>
  <string name="todo_edit_summary">Summary</string>
  <string name="todo_edit_description">Description</string>
  <string name="todo_edit_confirm">Confirm</string>
</resources>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" >

    <ImageView
        android:id="@+id/icon"
        android:layout_width="30dp"
        android:layout_height="24dp"
        android:layout_marginLeft="4dp"
        android:layout_marginRight="8dp"
        android:layout_marginTop="8dp"
        android:src="@drawable/reminder" >
    </ImageView>

    <TextView
        android:id="@+id/label"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="6dp"
        android:lines="1"
        android:text="@+id/TextView01"
        android:textSize="24dp" >
    </TextView>

</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <ListView
        android:id="@android:id/list"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" >
    </ListView>

    <TextView
        android:id="@android:id/empty"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/no_todos" />

</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <Spinner
        android:id="@+id/category"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:entries="@array/priorities" >
    </Spinner>

    <LinearLayout
        android:id="@+id/LinearLayout01"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" >

        <EditText
            android:id="@+id/todo_edit_summary"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:hint="@string/todo_edit_summary"
            android:imeOptions="actionNext" >
        </EditText>
    </LinearLayout>

    <EditText
        android:id="@+id/todo_edit_description"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="1"
        android:gravity="top"
        android:hint="@string/todo_edit_description"
        android:imeOptions="actionNext" >
    </EditText>

    <Button
        android:id="@+id/todo_edit_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/todo_edit_confirm" >
    </Button>

</LinearLayout>

package de.vogella.android.todos;

import android.app.ListActivity;
import android.app.LoaderManager;
import android.content.CursorLoader;
import android.content.Intent;
import android.content.Loader;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.view.ContextMenu;
import android.view.ContextMenu.ContextMenuInfo;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView.AdapterContextMenuInfo;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
import de.vogella.android.todos.contentprovider.MyTodoContentProvider;
import de.vogella.android.todos.database.TodoTable;

/*
 * TodosOverviewActivity affiche les éléments todo existants 
 * dans une liste
 * 
 * Vous pouvez en créer des nouveaux via l'option "Insert" de la     
 * ActionBar
 * Vous pouvez en effacer un via un appui prolongé sur l'élément
 */

public class TodosOverviewActivity extends ListActivity implements
    LoaderManager.LoaderCallbacks<Cursor> {
  private static final int ACTIVITY_CREATE = 0;
  private static final int ACTIVITY_EDIT = 1;
  private static final int DELETE_ID = Menu.FIRST + 1;
  // private Cursor cursor;
  private SimpleCursorAdapter adapter;

  
  /** Appelée quand l'activité est créée pour la première fois. */

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.todo_list);
    this.getListView().setDividerHeight(2);
    fillData();
    registerForContextMenu(getListView());
  }

  // crée le menu à base de la définition XML 
  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.listmenu, menu);
    return true;
  }

  // Réaction à la sélection dans le menu
  @Override
  public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
    case R.id.insert:
      createTodo();
      return true;
    }
    return super.onOptionsItemSelected(item);
  }

  @Override
  public boolean onContextItemSelected(MenuItem item) {
    switch (item.getItemId()) {
    case DELETE_ID:
      AdapterContextMenuInfo info = (AdapterContextMenuInfo) item
          .getMenuInfo();
      Uri uri = Uri.parse(MyTodoContentProvider.CONTENT_URI + "/"
          + info.id);
      getContentResolver().delete(uri, null, null);
      fillData();
      return true;
    }
    return super.onContextItemSelected(item);
  }

  private void createTodo() {
    Intent i = new Intent(this, TodoDetailActivity.class);
    startActivity(i);
  }

  // Ouvre la deuxième activité si un élément est cliqué
  @Override
  protected void onListItemClick(ListView l, View v, int position, long id) {
    super.onListItemClick(l, v, position, id);
    Intent i = new Intent(this, TodoDetailActivity.class);
    Uri todoUri = Uri.parse(MyTodoContentProvider.CONTENT_URI + "/" + id);
    i.putExtra(MyTodoContentProvider.CONTENT_ITEM_TYPE, todoUri);

    startActivity(i);
  }
  

  private void fillData() {

    // Champs de la (projection) de la base de données
    // Doit inclure le _id colonne pour que l'adapter fonctionne
    String[] from = new String[] { TodoTable.COLUMN_SUMMARY };
    // Champs dans l'UI vers laquelle le mappage est effectué
    int[] to = new int[] { R.id.label };

    getLoaderManager().initLoader(0, null, this);
    adapter = new SimpleCursorAdapter(this, R.layout.todo_row, null,  
        from,to, 0);

    setListAdapter(adapter);
  }

  @Override
  public void onCreateContextMenu(ContextMenu menu, View v,
      ContextMenuInfo menuInfo) {
    super.onCreateContextMenu(menu, v, menuInfo);
    menu.add(0, DELETE_ID, 0, R.string.menu_delete);
  }

  // crée un nouveau chargeur après l'appel à initLoader() 
  @Override
  public Loader<Cursor> onCreateLoader(int id, Bundle args) {
    String[] projection = { TodoTable.COLUMN_ID, TodoTable.COLUMN_SUMMARY };
    CursorLoader cursorLoader = new CursorLoader(this,
        MyTodoContentProvider.CONTENT_URI, projection, null, null, null);
    return cursorLoader;
  }

  @Override
  public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
    adapter.swapCursor(data);
  }

  @Override
  public void onLoaderReset(Loader<Cursor> loader) {
    // les données ne sont plus disponibles, supprimer la référence
    adapter.swapCursor(null);
  }

}

package de.vogella.android.todos;

import android.app.Activity;
import android.content.ContentValues;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.Toast;
import de.vogella.android.todos.contentprovider.MyTodoContentProvider;
import de.vogella.android.todos.database.TodoTable;

/*
 * TodoDetailActivity permet de saisir un nouveau a élément 
 * todo ou d'en modifier un
 */
public class TodoDetailActivity extends Activity {
  private Spinner mCategory;
  private EditText mTitleText;
  private EditText mBodyText;

  private Uri todoUri;

  @Override
  protected void onCreate(Bundle bundle) {
    super.onCreate(bundle);
    setContentView(R.layout.todo_edit);

    mCategory = (Spinner) findViewById(R.id.category);
    mTitleText = (EditText) findViewById(R.id.todo_edit_summary);
    mBodyText = (EditText) findViewById(R.id.todo_edit_description);
    Button confirmButton = (Button) findViewById(R.id.todo_edit_button);

    Bundle extras = getIntent().getExtras();

    // vérification de l'Instance sauvegardée
    todoUri = (bundle == null) ? null : (Uri) bundle
        .getParcelable(MyTodoContentProvider.CONTENT_ITEM_TYPE);

    // Ou passée par l'autre activité
    if (extras != null) {
      todoUri = extras
          .getParcelable(MyTodoContentProvider.CONTENT_ITEM_TYPE);

      fillData(todoUri);
    }

    confirmButton.setOnClickListener(new View.OnClickListener() {
      public void onClick(View view) {
        if (TextUtils.isEmpty(mTitleText.getText().toString())) {
          makeToast();
        } else {
          setResult(RESULT_OK);
          finish();
        }
      }

    });
  }

  private void fillData(Uri uri) {
    String[] projection = { TodoTable.COLUMN_SUMMARY,
        TodoTable.COLUMN_DESCRIPTION, TodoTable.COLUMN_CATEGORY };
    Cursor cursor = getContentResolver().query(uri, projection, null, null,
        null);
    if (cursor != null) {
      cursor.moveToFirst();
      String category = cursor.getString(cursor
          .getColumnIndexOrThrow(TodoTable.COLUMN_CATEGORY));

      for (int i = 0; i < mCategory.getCount(); i++) {

        String s = (String) mCategory.getItemAtPosition(i);
        if (s.equalsIgnoreCase(category)) {
          mCategory.setSelection(i);
        }
      }

      mTitleText.setText(cursor.getString(cursor
          .getColumnIndexOrThrow(TodoTable.COLUMN_SUMMARY)));
      mBodyText.setText(cursor.getString(cursor
          .getColumnIndexOrThrow(TodoTable.COLUMN_DESCRIPTION)));

      // toujours fermer le courseur
      cursor.close();
    }
  }

  protected void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    saveState();
    outState.putParcelable(MyTodoContentProvider.CONTENT_ITEM_TYPE, todoUri);
  }

  @Override
  protected void onPause() {
    super.onPause();
    saveState();
  }

  private void saveState() {
    String category = (String) mCategory.getSelectedItem();
    String summary = mTitleText.getText().toString();
    String description = mBodyText.getText().toString();

    // sauvegarder uniquement si sommaire ou description disponible

    if (description.length() == 0 && summary.length() == 0) {
      return;
    }

    ContentValues values = new ContentValues();
    values.put(TodoTable.COLUMN_CATEGORY, category);
    values.put(TodoTable.COLUMN_SUMMARY, summary);
    values.put(TodoTable.COLUMN_DESCRIPTION, description);

    if (todoUri == null) {
      // New todo
      todoUri = getContentResolver().insert(MyTodoContentProvider.CONTENT_URI, values);
    } else {
      // Update todo
      getContentResolver().update(todoUri, values, null, null);
    }
  }

  private void makeToast() {
    Toast.makeText(TodoDetailActivity.this, "Please maintain a summary",
        Toast.LENGTH_LONG).show();
  }
}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="de.vogella.android.todos"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk android:minSdkVersion="15" />

    <application
        android:icon="@drawable/icon"
        android:label="@string/app_name" >
        <activity
            android:name=".TodosOverviewActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name=".TodoDetailActivity"
            android:windowSoftInputMode="stateVisible|adjustResize" >
        </activity>

        <provider
            android:name=".contentprovider.MyTodoContentProvider"
            android:authorities="de.vogella.android.todos.contentprovider" >
        </provider>
    </application>

</manifest>

    adb shell

  # Switch to the data directory
  cd /data/data
  # Our application
  cd de.vogella.android.todos
  # Switch to the database dir
  cd databases
  # Check the content
  ls
  # Assuming that there is a todotable file
  # connect to this table
  sqlite3 todotable.db