Hi,

I am fairly new to Hibernate but I've got a design question about how best to build a query.

I new to design a query that will return a list of Companies based on Location and Business Type

I have 3 classes for each thing

- Companies
- RegisteredLocation
- BusinessType

Each class has it's own table. There are also two further Link tables.

COMPANY_LOCATION
COMPANY_BUSINESS_TYPE

So my method that I will be calling is,

getCompaniess(long locationId, long businessTypeId);

I'm not sure about how best to design the Mapping files. Do I need to put everything into the Companies mapping file. How do I reference these other classes from that mapping file and how do I go about constructing the HQL query.

Any pointers will be greatly appreciated. Apologies for not having any mapping files. Haven't started them yet as I am trying to figure out what the best way to do this is.

Mapping for company class
<class name="Companies" table="Comapnies">
<id>
<!-- Assuming company_id is key identifier. -->
</id>



<!-- Associations -->

<!-- bi-directional one-to-many association to COMPANY_LOCATION -->
<set name="COMPANY_LOCATION" lazy="false" inverse="true" cascade="none">
<key>
<column name="company_id"/>
</key>

<one-to-many class="COMPANY_LOCATION " />
</set>

<!-- bi-directional one-to-many association to COMPANY_BUSINESS_TYPE-->
<set name="COMPANY_BUSINESS_TYPE" lazy="false" inverse="true" cascade="none">
<key>
<column name="company_id" />
</key>

<one-to-many class="COMPANY_BUSINESS_TYPE" />
</set>
</class>

Mapping for location class:

<class name="Location" table="Location">
<id>
<!-- Assuming location_id is key identifier. -->
...
...
</id>

<!-- Associations -->

<!-- bi-directional one-to-many association to COMPANY_LOCATION -->
<set name="COMPANY_LOCATION" lazy="false" inverse="true" cascade="none">
<key>
<column name="location_id"/>
</key>

Similar mapping file for business type class also. This way you can retrieve and store objects from any class. For example you can access company object from location objects. Depending on what you select a value for "cascade" attribute it will determine whether you can store the linked abjects or not.

Hope this helps and gets you started.

If I want to use a List instead of Set, do I need to use <bag> versus <set> for COMPANY_LOCATION?

As long as you don't need to retain the order, you can use a <bag>.

You can find information about the different mappings for collections in sectin 7.2 of the reference.