CODEWITHSUNDEEP
javajpaquerydsl
haromt
haromt

Reputation: 81

QueryDSL projections and null values

given this query: 

final List list =
new JPAQuery(entityManager).from(qdevice).leftJoin(qdevice.parentDevice)
.list(Projections.bean(Device.class, qdevice.id, qdevice.parentDevice));

(parentDevice is type of Device )

The problem is that the query only return the Device when the parentDevice is not null. Why? How to get any value back? If I take out qdevice.parentDevice from the projection than the result is good.

QueryDsl version is 3.2.0

Upvotes: 4

Views: 2762

Answers (1)

Timo Westkämper
Timo Westkämper

Reputation: 22200

Could you try this

QDevice device = QDevice.device;
QDevice parentDevice = new QDevice("parentDevice");
List<Device> list = new JPAQuery(entityManager)
    .from(device)
    .leftJoin(device.parentDevice, parentDevice)
    .list(Projections.bean(Device.class, device.id, parentDevice));

The reference to qdevice.parentDevice in list might be treated as an inner join, since you don't relate it to the left join.

Upvotes: 3

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