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How to write the mapping file ?
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Edward Chen
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Joined: Dec 23, 2003
Posts: 758
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I am using hibernate IDE, I found some confusing. class A { B b; B[] b_array; String[] string_array; } class B{...} ---- say "B b"; One solution is <one-to-one name="b" class="B"/> anther solution is <component name="B" ... /> How to write the mapping file ?
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miguel lisboa
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Joined: Feb 08, 2004
Posts: 1281
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one thing i like in this forum is the fact that members arent rude as in other java forums; this said, i dont want to rtfm you, but i guess browsing this would help you a lot
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java amateur
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Edward Chen
Ranch Hand
Joined: Dec 23, 2003
Posts: 758
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The thing is this, I use Exadel ORMstudio to map object. I try the simple class just like above. The solution ORMStudio gava to me is "component ..." but I read the book and online tutorial, I think it should be "<one-to-one ..." . You see this difference. This is my confusing. So I post it here to ask for help. Do you think it is rude action ? I did a lot of homework before I post this question. Thanks
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miguel lisboa
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Joined: Feb 08, 2004
Posts: 1281
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Do you think it is rude action
you misunderstood me! i never intented to call you rude; i was refering some posters that are rude when answering newbie questions, that's all
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miguel lisboa
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Joined: Feb 08, 2004
Posts: 1281
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imagine you'v a class Person and a class Adress; you can map them both as entities - with database identifier; but, if you use what HiA authors call fine grained objects, you may as well map Adress as a component (a hibernate notion). Read this - they explain it:
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David Harkness
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Joined: Aug 07, 2003
Posts: 1646
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Do you want to be able to access the B objects outside of As? If so, they are entities and will have their own identifier. With that, you can load a B without loading its A. If the B is more like an Address (to use Miguel's example), you may only want to access it from the A. In that case, make it a component. The problem is that tools cannot know your intended use of the objects, so it simply picks a method to use.
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Edward Chen
Ranch Hand
Joined: Dec 23, 2003
Posts: 758
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Originally posted by David Harkness: Do you want to be able to access the B objects outside of As? If so, they are entities and will have their own identifier. With that, you can load a B without loading its A. If the B is more like an Address (to use Miguel's example), you may only want to access it from the A. In that case, make it a component. The problem is that tools cannot know your intended use of the objects, so it simply picks a method to use.
you mean, B is only accessed through A , B is sealed in A ---> component B is indepent object, ---> one-to-one ... When "component", actually it is ONE table. When "one-to-one", it is TWO tables. My understanding is right? Thanks for your help.
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Edward Chen
Ranch Hand
Joined: Dec 23, 2003
Posts: 758
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Originally posted by miguel lisboa: imagine you'v a class Person and a class Adress; you can map them both as entities - with database identifier; but, if you use what HiA authors call fine grained objects, you may as well map Adress as a component (a hibernate notion). Read this - they explain it:
Thanks for your help. the link you post is very helpful. Forget about the "rude" things, We are all in the same wonderful java community.
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subject: How to write the mapping file ?
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