reverse engineering a one to one relationship

[jay vas]

hi guys : I have a database where

table a references table b, and the reference is unique, i.e.

person(varchar name, int ssid) 
foreign key ssid references ref_ssid.ssid
ref_ssid(int ssid)

Now, I've reverse engineered the dao code in hibernate but for some reason, I have the following in my API ...

 
 
class Person{  
   HashSet<RefSSID> ssids... 
}
 

Anyways. This is really bothering me, because it complicates the API unnecessarily.

Since a unique column referencing a table key that is also unique, this should always be a one to one relationship, right ?

How can you clue in hibernate to do a one to one instead of a set? (Yes I've defined ssid as unique in the database).

[Stevi Deter]

Jay,

What tool are you using to do the reverse engineering?

The table structure you have defined would actually be one-to-many; you haven't defined any reverse restriction that there's a unique constraint on person (name + ssid). This is assuming that by stating you've defined ssid as unique, you mean as the primary key of ref_ssid. If you mean in the person table, then that should be sufficient.

You may want to double check your FK was correctly defined. If you did it in the order you described, it would have failed, because you can't add a FK to a table/field that doesn't yet exist. i.e., try:

ref_ssid(int ssid)
person(varchar name, int ssid) 
foreign key ssid references ref_ssid.ssid

But not knowing the full details or what tool your using, these are just best guesses.

[jay vas]

Yup - I definetly had the reverse constraint for uniquenss in there.... Im using the hibernate reverse engineering tool in the jboss ide.