Hibernation request to join criteria

Question

I have four tables: USER, CONTACT, CONACT_TYPE and USER_CONTACT

USER_CONTACT stores all contacts that the user has tables filled with dummy data, the following

USER TABLE

USER_ID(int)| FIRST_NAME(varchar(2) | LAST_NAME(varchar(2) | ------------------------------------------------------------ | 1 | TEST | USER | ------------------------------------------------------------ 

USER_CONTACT

 USER_CONTACT_ID(int) | USER_ID(int) | CONTACT_ID(int) | ------------------------------------------------------- | 1 | 1 | 1 | | 2 | 1 | 2 | | 3 | 1 | 3 | ------------------------------------------------------- 

CONTACT

 CONTACT_ID(int) | CONTACT_TYPE_ID(int) | CONTACT(varchar(2)| ------------------------------------------------------------- | 1 | 2 | [phone] | | 2 | 2 | [phone] | | 3 | 1 | [e-mail] | ------------------------------------------------------------- 

CONTACT_TYPE

 CONTACT_TYPE_ID(int) | CONTACT_TYPE | ------------------------------------- | 1 | EMAIL | | 2 | PHONE | ------------------------------------- 

What I'm trying to do is create a query that will return a list containing only CONACT_TYPE PHONE, here is my hibernation function so far

 public List<UserContact> getUserContactByType(Integer userId, String contactType) { Session session = getSessionFactory().openSession(); try { Criteria criteria = session.createCriteria(UserContact.class, "USER_CONACT"); criteria.add(Restrictions.eq("USER_CONACT.userId, userId"); criteria.add(Restrictions.eq("USER_CONTACT.contact.contactType.contactType", contactType); return (List<UserContact>)criteria.list(); } } 

Each table is mapped to a model class. Important class information is as follows.

Contact.java

Contains @ManyToOne relation to ContactType.java class

 @ManyToOne(optional = false, fetch = FetchType.EAGER) private ContactType contactType; 

UserContact.java

Contains @ManyToOne relation to the Contact.java class and @ManyToOne in the User.java class

 @ManyToOne(optional = false, fetch = FetchType.LAZY) private Contact contact; @ManyToOne(optional = false, fetch = FetchType.LAZY) private User user; 

All classes have standard getters and seters for all column attributes for the tables above.

I keep getting an error message indicating that it cannot resolve the contact.contactType property of my UserContact class. Does anyone know how to properly do something like this in sleep mode?

Answer 1

I realized this, I did not know about the createAlias ​​function. The solution is below if someone is wondering.

 public List<UserContact> getUserContactByType(Integer userId, String contactType) { Session session = getSessionFactory().openSession(); try { Criteria criteria = session.createCriteria(UserContact.class, "USER_CONACT"); criteria.add(Restrictions.eq("USER_CONACT.userId, userId"); criteria.createAlias("USER_CONACT.contact", "c"); criteria.add(Restrictions.eq("c.contactType.contactType", contactType); return (List<UserContact>)criteria.list(); } } 

Answer 2

Now you can use the use of Spring -Data-JPA with QueryDSL support!