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Groups > comp.lang.java.databases > #24
| From | "Spendius" <spendius@THRWHITE.remove-dii-this> |
|---|---|
| Subject | Hibernate M:M mapping plu |
| Message-ID | <ffeba001-8b9d-4511-91c0-277dd497397e@x35g2000hsb.googlegroups.com> (permalink) |
| Newsgroups | comp.lang.java.databases |
| Date | 2011-04-27 15:21 +0000 |
| Organization | TDS.net |
To: comp.lang.java.databases Hello, I'm asking a question already asked a few years ago: http://groups.google.be/group/comp.lang.java.databases/browse_frm/thread/c3a1045674b6b65f/c3aa99a30b22c8e6?hl=nl&lnk=gst&q=%22many-to-many%22&utoken=DT02DTsAAAAYHYTsDrEdq7-NnfRgl-Nk4GfRPBFGhDGPHFrvVDkRvgz1eTbjLK36WL5svdAfvL03TRB4SbQHh5KfXKICx3ka When your middle table (that which relates your 2 tables through a many-to-many relationship) contains more than the A_ID and B_ID columns but also -for ex.- DATE columns etc.- is there a way to deal with this extra info with some more config in your .hbm.xml files or do you really need a supplementary class to handle this data ? When you have no more than the 2 ID columns to deal with, the following mappings are enough: <set name="events" table="PERSON_EVENT"> <key column="PERSON_ID"/> <many-to-many column="EVENT_ID" class="Event"/> </set> in a file and <set name="participants" table="PERSON_EVENT" inverse="true"> <key column="EVENT_ID"/> <many-to-many column="PERSON_ID" class="Person"/> </set> in the other .hbm.xml file... And no specific class for the PERSON_EVENT database table is required - but when this table contains other columns, is there no way but to create another class to play with this extra columns ? In advance, thanks. Regards, Spendius --- * Synchronet * The Whitehouse BBS --- whitehouse.hulds.com --- check it out free usenet! --- Synchronet 3.15a-Win32 NewsLink 1.92 Time Warp of the Future BBS - telnet://time.synchro.net:24
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Hibernate M:M mapping plu "Spendius" <spendius@THRWHITE.remove-dii-this> - 2011-04-27 15:21 +0000 Re: Hibernate M:M mapping "Axel Hallez" <axel.hallez@THRWHITE.remove-dii-this> - 2011-04-27 15:21 +0000
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