Why org.hibernate.TransientObjectException during join/select? - criteria-api

Question

Trying to wrap my head around Criteria API (ouch). I have 3 classes: Devices, Offices, and SiteCodes. all joined
Devices.java
private Offices office;
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "office_id")
public Offices getOffice() {
return office;
}
public void setOffice(Offices office) {
this.office = office;
}
Offices.java:
private List<SiteCodes> siteCodes;
#ManyToMany(cascade = CascadeType.PERSIST)
#JoinTable(name = "site_code_map", joinColumns = {
#JoinColumn(name = "office_id") }, inverseJoinColumns = {
#JoinColumn(name = "site_code_id") })
#OrderBy("siteCode ASC")
public List<SiteCodes> getSiteCodes() {
return this.siteCodes;
}
public void setSiteCodes(List<SiteCodes> siteCodes) {
this.siteCodes = siteCodes;
}
SiteCodes.java
private id;
private String siteCode;
<getters and setters>
I'm trying to find Devices.devId using the site code. The sql would look like this:
SELECT d.dev_id
FROM devices d, offices o, site_code_map s, site_codes ss
WHERE d.office_id=o.office_id
AND s.office_id=o.office_id
AND s.site_code_id=ss.site_code_id
AND ss.`site_code`='0S21'
I'm trying to use joins, but don't quite get how to do it. I got the following to compile:
CriteriaBuilder cb = em.getCriteriaBuilder();
CriteriaQuery<Integer> cq = cb.createQuery(Integer.class);
Root<Devices> d = cq.from(Devices.class);
Join<Devices, Offices> join1 = d.join(Devices_.office);
ListJoin<Offices,SiteCodes> join2 = join1.join(Offices_.siteCodes);
I couldn't figure how to use join2 so I used join1 and a path like this
ParameterExpression<SiteCodes> p = cb.parameter(SiteCodes.class, "sitecode");
Predicate pr = cb.isMember(p, join1.get(Offices_.siteCodes));
cq.where(pr);
and eventually
TypedQuery<Integer> tq = em.createQuery(cq);
<set parameter here to a SiteCode object>
List<Integer> idList = tq.getResultList();
It produces sql like the following. That subquery doesn't belong - I want it to use a join and anyway it throws a TransientObjectException even though all I'm doing is selecting:
select
devices0_.dev_id as col_0_0_
from
devices devices0_
inner join
offices offices1_
on devices0_.office_id=offices1_.office_id
inner join
site_code_map sitecodes2_
on offices1_.office_id=sitecodes2_.office_id
inner join
site_codes sitecodes3_
on sitecodes2_.site_code_id=sitecodes3_.site_code_id
where
? in (
select
sitecodes4_.site_code_id
from
site_code_map sitecodes4_
where
offices1_.office_id=sitecodes4_.office_id
And anyway it also throws this error (not including whole stack trace unless sopmeone wants to see it):
Caused by: org.hibernate.TransientObjectException: object references an
unsaved transient instance - save the transient instance before
flushing: dne.nmst.dac.model.SiteCodes
This confused me because I wasn't doing any saving, just selecting.
How do I get this to work? I want the criteria constructed properly and of course to not have an error occur.

Answer 1

I got this worked out. Hope it helps someone else. Still don't know why I got the error it did, but I figured out the join's and that made the query work correctly
Joins:
Root<Devices> d = cq.from(Devices.class);
Join<Devices, Offices> join1 = d.join(Devices_.office);
ListJoin<Offices,SiteCodes> join2 = join1.join(Offices_.siteCodes);
Parameter expression and Predicate:
ParameterExpression<String> p = cb.parameter(String.class, "sitecode");
Predicate pr = cb.equal(join2.get(SiteCodes_.siteCode),p);
Produced SQL like this:
select
devices0_.dev_i a col_0_0
from
devices devices0
inner join
office offices1
o devices0_.office_id=offices1_.office_i
inner join
site_code_map sitecodes2
o offices1_.office_id=sitecodes2_.office_i
inner join
site_code sitecodes3
o sitecodes2_.site_code_id=sitecodes3_.site_code_i
where
sitecodes3_.site_code=?