android.database.DatabaseUtils#concatenateWhere ( )源码实例Demo

/**
 * Handle deleting data.
 */
@Override
public int delete(Uri uri, String where, String[] whereArgs) {
    SQLiteDatabase db = mOpenHelper.getWritableDatabase();
    String finalWhere;

    int count;

    switch (mUriMatcher.match(uri)) {
        case MAIN:
            // If URI is main table, delete uses incoming where clause and args.
            count = db.delete(MainTable.TABLE_NAME, where, whereArgs);
            break;

            // If the incoming URI matches a single note ID, does the delete based on the
            // incoming data, but modifies the where clause to restrict it to the
            // particular note ID.
        case MAIN_ID:
            // If URI is for a particular row ID, delete is based on incoming
            // data but modified to restrict to the given ID.
            finalWhere = DatabaseUtils.concatenateWhere(
                    MainTable._ID + " = " + ContentUris.parseId(uri), where);
            count = db.delete(MainTable.TABLE_NAME, finalWhere, whereArgs);
            break;

        default:
            throw new IllegalArgumentException("Unknown URI " + uri);
    }

    getContext().getContentResolver().notifyChange(uri, null);

    return count;
}
 

/**
 * Handle updating data.
 */
@Override
public int update(Uri uri, ContentValues values, String where, String[] whereArgs) {
    SQLiteDatabase db = mOpenHelper.getWritableDatabase();
    int count;
    String finalWhere;

    switch (mUriMatcher.match(uri)) {
        case MAIN:
            // If URI is main table, update uses incoming where clause and args.
            count = db.update(MainTable.TABLE_NAME, values, where, whereArgs);
            break;

        case MAIN_ID:
            // If URI is for a particular row ID, update is based on incoming
            // data but modified to restrict to the given ID.
            finalWhere = DatabaseUtils.concatenateWhere(
                    MainTable._ID + " = " + ContentUris.parseId(uri), where);
            count = db.update(MainTable.TABLE_NAME, values, finalWhere, whereArgs);
            break;

        default:
            throw new IllegalArgumentException("Unknown URI " + uri);
    }

    getContext().getContentResolver().notifyChange(uri, null);

    return count;
}