I have a question regarding JPA criteria.
Here is my JPA criteria query:
CriteriaBuilder criteriaBuilder = getEm().getCriteriaBuilder();
CriteriaQuery<InventoryItemSumReport> query = criteriaBuilder.createQuery(InventoryItemSumReport.class);
Root<InventoryItemDetail> from = query.from(InventoryItemDetail.class);
Join<InventoryItemDetail, InventoryItem> joinItem = from.join(InventoryItemDetail_.inventoryItem);
Predicate where = criteriaBuilder.lessThanOrEqualTo(from.get(InventoryItemDetail_.effectiveDate), date);
query.multiselect(joinItem.get(InventoryItem_.product),joinItem.get(InventoryItem_.facility),joinItem.get(InventoryItem_.customer));
query.groupBy(joinItem.get(InventoryItem_.product),joinItem.get(InventoryItem_.facility),joinItem.get(InventoryItem_.customer));
query.where(where);
TypedQuery<InventoryItemSumReport> createQuery = getEm().createQuery(query);
List<InventoryItemSumReport> resultList = createQuery.getResultList();
Here is the resulting query produced by the JPA provider:
select
inventoryi1_.PRODUCT_ID as col_0_0_,
inventoryi1_.FACILITY_ID as col_1_0_,
inventoryi1_.CUSTOMER_ID as col_2_0_
from
INVENTORY_ITEM_DETAIL inventoryi0_
inner join
INVENTORY_ITEM inventoryi1_
on inventoryi0_.INVENTORY_ITEM_ID=inventoryi1_.ID
inner join
PRODUCT product2_
on inventoryi1_.PRODUCT_ID=product2_.ID
inner join
FACILITY facility3_
on inventoryi1_.FACILITY_ID=facility3_.ID
inner join
CUSTOMER customer4_
on inventoryi1_.CUSTOMER_ID=customer4_.ID
where
inventoryi0_.EFFECTIVE_DATE<= ?
group by
inventoryi1_.PRODUCT_ID ,
inventoryi1_.FACILITY_ID ,
inventoryi1_.CUSTOMER_ID
But I would like the following query:
select
inventoryi1_.PRODUCT_ID as col_0_0_,
inventoryi1_.FACILITY_ID as col_1_0_,
inventoryi1_.CUSTOMER_ID as col_2_0_
from
INVENTORY_ITEM_DETAIL inventoryi0_
inner join
INVENTORY_ITEM inventoryi1_
on inventoryi0_.INVENTORY_ITEM_ID=inventoryi1_.ID
inner join
PRODUCT product2_
on inventoryi1_.PRODUCT_ID=product2_.ID
inner join
FACILITY facility3_
on inventoryi1_.FACILITY_ID=facility3_.ID
left join
CUSTOMER customer4_
on inventoryi1_.CUSTOMER_ID=customer4_.ID
where
inventoryi0_.EFFECTIVE_DATE<= ?
group by
inventoryi1_.PRODUCT_ID ,
inventoryi1_.FACILITY_ID ,
inventoryi1_.CUSTOMER_ID
with a left join CUSTOMER to get also results where Customers
are null.
Customer
, Product
, Facility
are all entites, while InventoryItemSumReport
is a Value object or DTO.
public class InventoryItemSumReport implements Serializable {
private static final long serialVersionUID = 1L;
private Product product;
private Facility facility;
private Customer customer;
public InventoryItemSumReport(Product product, Facility facility, Customer customer) {
super();
this.product = product;
this.facility = facility;
this.customer = customer;
}
}
I found as follows it works:
CriteriaBuilder criteriaBuilder = getEm().getCriteriaBuilder();
CriteriaQuery<InventoryItemSumReport> query = criteriaBuilder.createQuery(InventoryItemSumReport.class);
Root<InventoryItemDetail> from = query.from(InventoryItemDetail.class);
Join<InventoryItemDetail, InventoryItem> joinItem = from.join(InventoryItemDetail_.inventoryItem);
Predicate where = criteriaBuilder.lessThanOrEqualTo(from.get(InventoryItemDetail_.effectiveDate), date);
Join<InventoryItem, Customer> joinCustomer = joinItem.join(InventoryItem_.customer, JoinType.LEFT);
query.multiselect(joinItem.get(InventoryItem_.product),joinItem.get(InventoryItem_.facility),joinItem.get(InventoryItem_.customer));
query.groupBy(joinItem.get(InventoryItem_.product),joinItem.get(InventoryItem_.facility),joinCustomer);
query.where(where);
TypedQuery<InventoryItemSumReport> createQuery = getEm().createQuery(query);
List<InventoryItemSumReport> resultList = createQuery.getResultList();