Hibernate/JPA, field 'accreditation_company_id' doesn't have a default value error - spring

Question

I faced the issue described in the title saving my entity though everything in code and db tables seems ok.
Here is my code:
#Entity
public class Company {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
Long id;
#OneToMany(cascade = CascadeType.ALL)
#JoinColumn(name = "company_id", referencedColumnName = "id")
List<CompanyObject> companyObjects;
}
#Entity
public class CompanyObject {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
Long id;
#Enumerated(EnumType.STRING)
ObjectType type;
}
Here is my table definitions:
CREATE TABLE `company` (
`id` bigint(20) NOT NULL AUTO_INCREMENT,
PRIMARY KEY (`id`),
) ENGINE=InnoDB AUTO_INCREMENT=32 DEFAULT CHARSET=utf8
CREATE TABLE `company_object` (
`id` bigint(20) NOT NULL AUTO_INCREMENT,
`company_id` bigint(20) NOT NULL,
`type` varchar(50) NOT NULL,
PRIMARY KEY (`id`),
KEY `FK__company` (`company_id`),
CONSTRAINT `FK__company` FOREIGN KEY (`company_id`) REFERENCES `company` (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8
Object I'm trying to save contains the following info:
Company(id=32, companyObjects=[CompanyObject(id=null, type=NEW)])
Here is the code I use to save the object:
Controller method:
#RequestMapping(value = "/company/{id}", method = RequestMethod.POST)
public String editCompany(#PathVariable("id") long companyId,
#ModelAttribute("form") CompanyDto form) {
Company company = companyService.getCompanyById(companyId);
companyService.updateCompany(company, form);
return "redirect:/companies";
}
Service method:
#Transactional
public Company updateCompany(Company company, final CompanyDto form) {
company.getCompanyObjects().clear();
company.getCompanyObjects().addAll(form.getCompanyObjects());
return companyRepository.save(company);
}
Am I getting this right that hibernate automatically generate and populate all the missing ids in these objects? If yes what am I missing and why the error appears?

Answer 1

You have some problems here. Firstly, your table definitions are wrong, check your accreditation_object table, you have a foreign key there which references a column that doesn't exist: company_id should be accreditation_company_id.
(or is it just some copy-paste error?)
Secondly, your entities are wrong, try this way:
#Entity
public class Company {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
Long id;
#OneToMany(mappedBy="company", cascade = CascadeType.ALL)
Set<CompanyObject> companyObjects;
}
#Entity
public class CompanyObject {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
Long id;
#Enumerated(EnumType.STRING)
ObjectType type;
#ManyToOne
#JoinColumn(name = "company_id")
Company company;
}
Note the #ManyToOne annotation in the CompanyObject. If I understand correctly, you want to assign one or more CompanyObject to a Company, thus you have to have a #ManyToOne annotated Company typed field in the CompanyObject.
Now, if you want to save these objects, first save the Company instance, then iterate over the list of CompanyObjects, set the previously saved company instance, and then save the CompanyObjects, something like this:
Company company = new Company();
companyDao.persist(company);
List<CompanyObject> companyObjects = new ArrayList<>();
// populate the list somehow
// ...
for(CompanyObject obj: companyObjects){
obj.setCompany(company);
companyObjectDao.persist(obj);
}
Your updateCompany method is wrong, you should try something like the above code. (I cannot rewrite your example because it looks like something is missing there. What is CompanyDTO?)
Edit: You can use cascade saving (note: I've updated the Company entity), just be sure to set the Company instance to every CompanyObject instance, like:
#Transactional
public Company updateCompany(Company company, final CompanyDto form) {
company.getCompanyObjects().clear();
company.getCompanyObjects().addAll(form.getCompanyObjects());
for(CompanyObject obj : company.getCompanyObjects()){
obj.setCompany(company);
}
return companyRepository.save(company);
}
I think this should work, but I'm not a 100% sure. Give it a try.