Android Méthodes d'aide pour les requêtes SELECT, INSERT, DELETE, UPDATE


Exemple

Cet exemple montre une classe d'assistance qui contient des méthodes utiles lors de l'exécution des requêtes pour les données. Chaque méthode utilise Java Generic afin d'être très flexible.

public <T> List<T> selectElements(AbstractDao<T, ?> dao) {
    if (dao == null) {
        return null;
    }
    QueryBuilder<T> qb = dao.queryBuilder();
    return qb.list();
}

public <T> void insertElements(AbstractDao<T, ?> absDao, List<T> items) {
    if (items == null || items.size() == 0 || absDao == null) {
        return;
    }
    absDao.insertOrReplaceInTx(items);
}

public <T> T insertElement(AbstractDao<T, ?> absDao, T item) {
    if (item == null || absDao == null) {
        return null;
    }
    absDao.insertOrReplaceInTx(item);
    return item;
}

public <T> void updateElements(AbstractDao<T, ?> absDao, List<T> items) {
    if (items == null || items.size() == 0 || absDao == null) {
        return;
    }
    absDao.updateInTx(items);
}

public <T> T selectElementByCondition(AbstractDao<T, ?> absDao,
                                      WhereCondition... conditions) {
    if (absDao == null) {
        return null;
    }
    QueryBuilder<T> qb = absDao.queryBuilder();
    for (WhereCondition condition : conditions) {
        qb = qb.where(condition);
    }
    List<T> items = qb.list();
    return items != null && items.size() > 0 ? items.get(0) : null;
}

public <T> List<T> selectElementsByCondition(AbstractDao<T, ?> absDao,
                                             WhereCondition... conditions) {
    if (absDao == null) {
        return null;
    }
    QueryBuilder<T> qb = absDao.queryBuilder();
    for (WhereCondition condition : conditions) {
        qb = qb.where(condition);
    }
    List<T> items = qb.list();
    return items != null ? items : null;
}

public <T> List<T> selectElementsByConditionAndSort(AbstractDao<T, ?> absDao,
                                                    Property sortProperty,
                                                    String sortStrategy,
                                                    WhereCondition... conditions) {
    if (absDao == null) {
        return null;
    }
    QueryBuilder<T> qb = absDao.queryBuilder();
    for (WhereCondition condition : conditions) {
        qb = qb.where(condition);
    }
    qb.orderCustom(sortProperty, sortStrategy);
    List<T> items = qb.list();
    return items != null ? items : null;
}

public <T> List<T> selectElementsByConditionAndSortWithNullHandling(AbstractDao<T, ?> absDao,
                                                                    Property sortProperty,
                                                                    boolean handleNulls,
                                                                    String sortStrategy,
                                                                    WhereCondition... conditions) {
    if (!handleNulls) {
        return selectElementsByConditionAndSort(absDao, sortProperty, sortStrategy, conditions);
    }
    if (absDao == null) {
        return null;
    }
    QueryBuilder<T> qb = absDao.queryBuilder();
    for (WhereCondition condition : conditions) {
        qb = qb.where(condition);
    }
    qb.orderRaw("(CASE WHEN " + "T." + sortProperty.columnName + " IS NULL then 1 ELSE 0 END)," + "T." + sortProperty.columnName + " " + sortStrategy);
    List<T> items = qb.list();
    return items != null ? items : null;
}

public <T, V extends Class> List<T> selectByJoin(AbstractDao<T, ?> absDao,
                                                 V className,
                                                 Property property, WhereCondition whereCondition) {
    QueryBuilder<T> qb = absDao.queryBuilder();
    qb.join(className, property).where(whereCondition);
    return qb.list();
}

public <T> void deleteElementsByCondition(AbstractDao<T, ?> absDao,
                                          WhereCondition... conditions) {
    if (absDao == null) {
        return;
    }
    QueryBuilder<T> qb = absDao.queryBuilder();
    for (WhereCondition condition : conditions) {
        qb = qb.where(condition);
    }
    List<T> list = qb.list();
    absDao.deleteInTx(list);
}

public <T> T deleteElement(DaoSession session, AbstractDao<T, ?> absDao, T object) {
    if (absDao == null) {
        return null;
    }
    absDao.delete(object);
    session.clear();
    return object;
}

public <T, V extends Class> void deleteByJoin(AbstractDao<T, ?> absDao,
                                              V className,
                                              Property property, WhereCondition whereCondition) {
    QueryBuilder<T> qb = absDao.queryBuilder();
    qb.join(className, property).where(whereCondition);
    qb.buildDelete().executeDeleteWithoutDetachingEntities();
}

public <T> void deleteAllFromTable(AbstractDao<T, ?> absDao) {
    if (absDao == null) {
        return;
    }
    absDao.deleteAll();
}

public <T> long countElements(AbstractDao<T, ?> absDao) {
    if (absDao == null) {
        return 0;
    }
    return absDao.count();
}