SQLiteConstraintException: code d'erreur 19: la contrainte a échoué - Erreur Android

J'ai vu quelques autres questions à ce sujet, mais aucune réponse ne semblait vraiment travailler pour mon code. Je suis un 'SQLiteConstraintException: erreur code 19: contrainte a échoué' erreur lorsque j'essaie d'insérer dans ma DB. Voici le code pour l'opération d'insertion. db.insérez retourne -1 droit maintenant, ce qui conduit à la "impossible d'insérer un" message.

Ici, c'est le Contenu pertinent code Fournisseur:

public static final String PROVIDER_NAME = "com.oliverapps.provider.DB";
public static final Uri CONTENT_URI = Uri.parse("content://"+ PROVIDER_NAME + "/tasks");
public static final String _ID = "_id";
public static final String CATEGORY = "category";
public static final String STORE = "store";
public static final String DESCRIPTION = "description";
public static final String DISTANCE = "distance";
public static final String CHECKED = "checked";
private static final int KEY_CATEGORY = 1;
private static final int KEY_STORE = 2;
private static final int KEY_DESCRIPTION = 3;
private static final int KEY_DISTANCE = 4;
private static final int KEY_CHECKED = 5;
private static final UriMatcher uriMatcher;
static{
uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
uriMatcher.addURI(PROVIDER_NAME, "category", KEY_CATEGORY);
uriMatcher.addURI(PROVIDER_NAME, "category/store", KEY_STORE);
uriMatcher.addURI(PROVIDER_NAME, "category/store/description", KEY_DESCRIPTION);
uriMatcher.addURI(PROVIDER_NAME, "category/store/description/distance", KEY_DISTANCE);
uriMatcher.addURI(PROVIDER_NAME, "checked", KEY_CHECKED);
}
//---for database use---
private SQLiteDatabase tasksDB;
private static final String DATABASE_NAME = "tasks";
private static final String DATABASE_TABLE = "tasks" +
"";
private static final int DATABASE_VERSION = 1;
private static final String DATABASE_CREATE =
"create table " + DATABASE_TABLE +
" (" + _ID +  " integer primary key autoincrement, " +
CATEGORY + " text not null, " + STORE + " text not null, " + DESCRIPTION + " text, " +
DISTANCE + " text not null, " + CHECKED + " text not null);";
private static class DatabaseHelper extends SQLiteOpenHelper{
DatabaseHelper(Context context){
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db){
db.execSQL(DATABASE_CREATE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion){
Log.w("Content provider database", "Upgrading database from version " +
oldVersion + " to " + newVersion + ", which will destroy all old data");
db.execSQL("DROP TABLE IF EXISTS " + DATABASE_TABLE);
onCreate(db);
}
}
@Override
public Uri insert(Uri uri, ContentValues values){
//---add a new task---
long rowID = tasksDB.insert(DATABASE_TABLE, "", values);
//---if added successfully---
if(rowID > 0){
Uri _uri = ContentUris.withAppendedId(CONTENT_URI, rowID);
getContext().getContentResolver().notifyChange(_uri, null);
return _uri;
}
throw new SQLException("Failed to insert row into " + uri);
}
@Override
public boolean onCreate(){
Context context = getContext();
DatabaseHelper dbHelper = new DatabaseHelper(context);
tasksDB = dbHelper.getWritableDatabase();
return (tasksDB == null)? false:true;
}

Voici le code à partir de l'Android Manifeste:

    <provider android:name="DBProvider"
android:authorities="com.oliverapps.provider.DB" />

Et voici le code qui appelle la méthode d'insertion ci-dessus:

ContentValues values = new ContentValues();
values.put(DBProvider.CATEGORY, category);
values.put(DBProvider.STORE, store);
values.put(DBProvider.DESCRIPTION, description);
values.put(DBProvider.DISTANCE, distance);
Uri uri = getContentResolver().insert(DBProvider.CONTENT_URI, values);

Aucune idée de pourquoi cela ne fonctionne pas? C'est surtout le code à partir d'un Android livre que j'ai modifiée à ma propre base de données.

source d'informationauteur Rebecca