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Edit primary key, if it's a foreign key

 
Hajdu Attila
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I have a problem: I can't know, how edit primary key, if this key is a foreign key...
ER:

I want to edit curseId, but I can't...

User.java


Curse.java


CurseId.java


UserCurse.java


UserCurseId.java


Thanks for helping!
 
David Newton
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IntelliJ IDE Ruby
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(Off-topic: are you keeping a list of the swear words the students use? ;) It's "course", not "curse" :)
 
Hajdu Attila
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David Newton wrote:(Off-topic: are you keeping a list of the swear words the students use? ;) It's "course", not "curse" :)

Thank you for your comments! It's meaning course, of course :mrgreen:
OFF: My university have "NEPTUN" web based education system, and theme of my thesis is a same system. In NEPTUN, it's "curse"...
 
James Sutherland
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What do you mean by "edit", update?

You cannot update a primary key. You should delete the UserCurse object, and add a new one to the different Curse.

For an insert, you can just create the new UserCurse and set its Id.

 
Hajdu Attila
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James Sutherland wrote:What do you mean by "edit", update?

Simple update courseId, for example...

Before:
Curses
curse_id semester_id ....
old 2010
old2 2010

Users_curses
curse_id semester_id user_id ...
old 2010 shark300

After:
Curses
curse_id semester_id ....
new 2010
old2 2010

Users_curses
curse_id semester_id user_id ...
new 2010 shark300

Any idea for editing Curse entity?
 
Paul Sturrock
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Eclipse IDE Hibernate Java
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As James points out, editing a primary key == inserting a new record. So I'd do what he's already suggested, delete the existing records and a a new one.
 
Hajdu Attila
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This code don't create row in Users_Course... I know, if I create some new instances of UserCourse with "modifiedCourseId" courseId, rows are created.
But if this row is edited, I have to edit all instance in database, where courseId is "sub-primary key".

Any idea for editing Curse entity?
 
Paul Sturrock
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What is a "sub-primary" key?
 
Hajdu Attila
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Paul Sturrock wrote:What is a "sub-primary" key?


courseId is a element of multiple primary key of Checks table.

Check.java


CheckId.java
 
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