Cascade not working

kukudas · **Joined:** Wed Apr 09, 2008 10:28 am **Posts:** 52

hi,

this is my situation:

Code:

@ManyToMany(fetch=FetchType.EAGER, cascade={CascadeType.ALL})
@org.hibernate.annotations.Cascade(value={org.hibernate.annotations.CascadeType.ALL}) 
@JoinTable(name="User_Details",joinColumns={@JoinColumn(name="username",referencedColumnName="username")}, inverseJoinColumns={@JoinColumn(name="authority",referencedColumnName="authority")})
    private Set<Authority> authlist;

Basicly i have 2 Tables Users and Authorities both of them have a Integer Id as Primary Key. I want to store the username from Users and the authority from Authorities into the JoinTable.
But when i make service.read(1); for the first user for example the
authlist's size is 0 meaning nothing is in there even if the Table user_details contains data. Somehow it doesnt fetch the values?
Somebody know how to fix this??

thx kuku[/u]

kukudas · **Joined:** Wed Apr 09, 2008 10:28 am **Posts:** 52

i think the problem is that i dont use the pk id as fk in user_details so hibernate don'T know how to fetch or so .. but i don't understand why this doesnt work .. or how to fix it. the hole point of my manytomany was that i have a jointable where i have the username and the authoritys at one location.

sanne.grinovero · **Posted:** Wed Jun 04, 2008 6:21 am

Quote:

I think the problem is that i dont use the pk id as fk in user_details

you're right, you have to use the PKs.
Nothing stops you to also store the usernames and more data in the same join table.

BTW this has nothing to do with "Cascade"

kukudas · **Joined:** Wed Apr 09, 2008 10:28 am **Posts:** 52

ok thanks but how do i tell that i want another field in that jointable which is not an FK ? i know how to add more joincolumns but i think thats not the correct way.
edit: yes seems that is a mapping problem and not cascade issue.

sanne.grinovero · **Posted:** Wed Jun 04, 2008 6:36 am

Quote:

I want to store the username from Users and the authority from Authorities into the JoinTable.

You mean you only want username and authority in the jointable?
this really looks bad design, I would suggest to use PK and FK, why would you want to avoid the two integers?
using the integer PK will perform much better and is safer for your data integrity.

Mybe I'm completely wrong, could you explain the reason for this requirement?

kukudas · **Joined:** Wed Apr 09, 2008 10:28 am **Posts:** 52

it's okay to have the id's in the jointable as FK's, but i dont know how to add username and authority as normal fields into this jointable too thats my problem.

The reason why i want this 2 fields in the table is that i can access them easy like select username authority from user_details where username=?.

sanne.grinovero · **Posted:** Wed Jun 04, 2008 6:56 am

So I understand you want the list of authorities for a known username?
why not just

Code:

User user = s.createQuery("from User user where user.username='kukudas'").singleResult();
Set<Authority> authlist = user.getAuthList();

or

Code:

List authlist = s.createQuery("select user.authlist from User user where user.username='kukudas'").list();

kukudas · **Joined:** Wed Apr 09, 2008 10:28 am **Posts:** 52

gonna try it tommorrow. the reason why i want in user_details username and authority is because i'm using acegi security and in the spring configuration i have to set an sql statement how to fetch the username and authority so i can get authentication. if i don't have them in one table i dont know how to fetch them because my knowdgledge of sql is very poor. for now im using select username,authority from user_details where username=?.
if i have a construct where i have only user_id and auth_id in user_Details i don't know how to make an sql querry to read the username and authority for a specific user "?".

Cameron McKenzie · **Posted:** Wed Jun 04, 2008 9:58 am

Indeed, this has to do with the mapping of the keys to the join table.

For more help on mapping many to many associations with Hibernate and JPA, you may be interested in this tutorial. There are also discussions on CascadeType and Lazy Loading:

http://www.hiberbook.com/HiberBookWeb/learn.jsp?tutorial=19mappingmanytomanyrelationships

-Cameron McKenzie

sanne.grinovero · **Posted:** Wed Jun 04, 2008 12:19 pm

Hi kukudas,
thanks now I understand; If I may offer my advice is to not build your application on some strange model just because you would have to learn a bit of SQL.
the SQL query you have to write is really simple, you should be able to write it following some simple tutorial about JOIN.

sanne.grinovero · **Posted:** Wed Jun 04, 2008 12:22 pm

BTW to Cameron:
nice examples on your website! thanks.

kukudas · **Joined:** Wed Apr 09, 2008 10:28 am **Posts:** 52

your right i should not base my model on some weak knowledge of sql. so it is basicly best way like this:
1. Table User with Id as PK and some values
2. Table Authority with Id as PK and one Field which containts the Authority.
and the join table which contains User.Id and Authority.Id and nothing more (not even a own ID). It may seem simpel but im still beginner and ive changed my datamodell so often which makes me sick its really a pain in the ass so this time i wanna do it right =).

kukudas · **Joined:** Wed Apr 09, 2008 10:28 am **Posts:** 52

i will look into the tutorial next day thanks cameron ;)

kukudas · **Joined:** Wed Apr 09, 2008 10:28 am **Posts:** 52

Ok here i'm again i've read the tutorial it was really great thanks for that. I have a question as u can see in my first posting i did the complete JoinTable on one side (in User class) is this ok? In the tutorial it is made for each side the reference.

my other side looks like this (in Authority):

Code:

    @ManyToMany(mappedBy="authlist",fetch=FetchType.EAGER)
    private List<User> userlist;

for now everything is working fine adding and removing elements of the collection and updating database. The only thing i need now is a appropriate sql or hql statement to fetch the username and authority to a specific user.
i will now look into JOIN. Thanks again for your help guys ;)