Hello All
I am a Hibernate newbie, and now looking for solution to handle my lookup tables. I mean those tables with 2 columns for id and name, such as country (1, "USA").
I searched and encountered some solutions that describe the use of a class for the lookup table.

Now - I think it is a pure waste. I do not regard the "country" table as an entity, but merely a warehouse for holding the list of countries, and for normalization. I really have no use to a "Country" class..

Further more, in my object model, I would really like to see I.E. in my "Contact" class a field of country of type String. Because I am interested in the country name...

Because I am also building a GUI, and would like to allow my user to have a "select box" of countries, I would also have something like "getCountries()" in my "Contact" class, to return a map of ID's, and String objects - with the county names.

My question is - Is there a way do achieve that using Hibernate, and if not - why ?

What is your objection to having an Object that is a country ? Since it's reference data that probably won't be updated often you can aggressively cache these objects using the second-level cache.

If you want to maintain the relationship of id and name in a collection, don't you need an object ?

We are using a lookup table to store all kindsof lookup values like status, payment method types etc.

These values are preloaded into a collection during application start up, so there is not roundtrip to the database to get these values. In our case these are static values and do not change that often.

But for individual types we have a class which the application can use if needed.

Hbm File
<class
name="com.fox.residuals.model.system.lookup.Lookup"
table="RESD_LOOKUP_CODE"
>

<id
name="lookupCode"
type="java.lang.String"
column="Lookup_code"
length="200"
>
<generator class="assigned" />
</id>
<discriminator column="LOOKUP_TYPE" type="string" />

<property
name="creationDate"
type="java.sql.Timestamp"
column="CREATION_DATE"
length="7"
/>
<property
name="modifiedDate"
type="java.sql.Timestamp"
column="MODIFIED_DATE"
length="7"
/>
<property
name="activeFlag"
type="yes_no"
column="ACTIVE_FLAG"
length="2"
/>

<property
name="version"
type="integer"
column="version"
/>


<property
name="displayedValue"
type="java.lang.String"
column="DISPLAYED_VALUE"
length="200"
/>
<property
name="lookupDescription"
type="java.lang.String"
column="LOOKUP_DESCRIPTION"
length="200"

/>

<subclass name="com.fox.residuals.model.system.lookup.ScheduleType" discriminator-value="SCHEDULETYPE"
>
</subclass>

<subclass name="com.fox.residuals.model.system.lookup.UnionPayType" discriminator-value="UNIONPAYTYPE"
>

There are integrity constraints at the DB level. We feel this will also help the reporting system

Hope this helps

My objection is that my object model has an extra class only for hibernate needs. I do not need it. And I hoped the O.R. mapping can allow me to have just the object model I need..



No, I just need a map, with a simple long as an ID, and a simple String for its value. This is true for most of my lookup tables.

I am not sure I understand. So you do not have an object for each lookup ? Where is the collection stored ? Could you ellaborate ? maybe with an example ?



So this mean you have a DB schema with a 1 table with a "lookup_type" column right ?
My DB schema is diferent. I have some table, each one is for 1 lookup. I wouldnt want to change the DB schema, as it is currently perfect for my needs.

Hello, eladm; have you received a satisfactory reply to this issue? I am facing the exact same issue as you, and as you've experienced in this particular topic, there doesn't seem to be a best practice here. I am about to resort to wild improvising.

Anyhow, if you've heard differently, please post any answer you've received!

Best,
Laird