Example
This example shows a helper class that contains methods useful, when executing the queries for data. Every method here uses Java Generic's in order to be very 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();
}
