"Wolfgang Knauf" wrote : Hi, | | assume that you have a relation "Person has many addresses" with two entities "Person" and "Address". | | If you declare a bidirectional relationship, your code can navigate from Person to Address, and from Adress to Person. | | With a unidirectional relationship, your code can navigate only from one side to the other. E.g. you can get the addresses of a person, but you cannot get the person of an address. | | The database representation of the relationship is not affected by your unidirectional/bidirectional decision. This defines only, how the code side looks like. | | Hope this helps | | Wolfgang tHANK U so much sir , Now i can see the difference but i have a new question another time, i'm developping an oaw project so after generating the code i have to build tables, That's why i used jboss ,but when i wanna add the oaw project in the server(add and remove option by right click on the sever ),i can not find the name of the oaw project ,So i created a new ejb3 project and i copy and paste the generated class into it finally i added the annotation and the relation ships into entities is it a good idea!!! Because My collegues add annotation (ejb3 code)in the Template!! That's why i'm wondering ,and I'm afraid if made a mistake!! What do you think Sir Knauf!! Viele Danke für Ihre Hilfe!! Thank you for ur help View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4269838#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...