Hello All.
I have a normalized legacy table structure I’m trying to map to a legacy class structure. I have 2 tables, named “items” and “item_types” (a lookup table), in which I’ve included the SQL DDL. I want to map them to a class defined below. I’ve included the mapping I’ve used which works great for querying the data. However, I’d like to save the data as well. I couldn’t figure out how to make Hibernate aware of the sequence in the item_types look-up table joined to my main table. I’m working with a legacy database and legacy class system, so I cannot easily create classes for each table.
I’d like to instantiate a class, assign a value to the classes types property and have it persist to the item table with the correct foreign key. Ideally, if a new “item_types.type” is added, it would get the next sequence value, insert the new type into item_types, and insert the new item with the correct foreign key for the new item type.
I assume I need to use the <join> tag, but I couldn’t figure out how to make it aware of my sequence.
Thanks in advance
Steven
Here's my mapping:
Code:
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="Item" table="items">
<id name="id" column="id">
<generator class="sequence">
<param name="sequence">types_sequence</param>
</generator>
</id>
<property name="prop1" column="prop1"/>
<property name="prop2" column="prop2"/>
<join table="item_types">
<key column="type_id"/>
<property name="type" column="type"/>
</join>
</class>
</hibernate-mapping>
Code:
create table items(
id int primary key,
prop1 varchar2(50),
prop2 varchar2(50),
...
item_type int references item_types(type_id)
);
create table item_types(
type_id int primary key,
type varchar(25)
);
Here's my class:
Code:
public class Item{
int id;
String prop1;
String prop2;
String type;
}
I'm using Hibernate 3 on Oracle9i.
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