I have problem with assiciations for the following relations:

a person can purchase many items.
so records in purchase table can be like following:

person1, item1, qty,amt, time
person1,item2,qty,amt,time
.....



CREATE TABLE person (
person_id bigint(10) NOT NULL,
person_name varchar(50) default NULL
PRIMARY KEY (person_id)
)
CREATE TABLE item (
item_id bigint(10) default NULL,
item_name varchar(100) default NULL,
item_price double(10,2) default NULL )
CREATE TABLE purchase (

purchase_id bigint(10) NOT NULL default '0',
person_id bigint(10) NOT NULL default '0', item_id bigint(10) default NULL, quantity int(10) default NULL, amount double(10,2) default NULL, date_purchase datetime default NULL PRIMARY KEY (`purchase_id`)
)

i need to insert records into the purchase table and i need to retriview the information from the table. Please suggest me key mappings in hbm files.
i am stuck with creating hbms. Please help me in understanding this scenario.

Thanks in advance,

You need to have classes corresponding to Person, Item and Purchase. Assuming that you will not be accessing purchases from an item, I guess you need something like:

<class name="Person" table="PERSON">
<id name="id" type="java.lang.Long" column="PERSON_ID" ></id>
<property name="name" column="PERSON_NAME" type="string"/>
<set name="purchases">
<key>
<column name="PERSON_ID"/>
</key>
<one-to-many class="myData.Purchase"/>
</set>
</class>
<class name="Item" table="ITEM">
<id name="id" type="java.lang.Long" column="ITEM_ID" ></id>
<property name="name" column="ITEM_NAME" type="string"/>
<property name="price" column="ITEM_PRICE" type="double"/>
</class>
<class name="Purchase" table="PURCHASE">
<id name="id" type="java.lang.Long" column="PURCHASE_ID" ></id>
<property name="quantity" column="QUANTITY" type="int"/>
<property name="amount" column="AMOUNT" type="double"/>
<property name="purchaseDate" column="DATE_PURCHASE" type="timestamp"/>
<many-to-one name="person" column="PERSON_ID" class="myData.Person" not-null="true"/>
<many-to-one name="item" column="ITEM_ID" class="myData.Item" not-null="true"/>
</class>

Refer to hibernate documentation for more information on mapping and associations.

Thanks for the help...
i got good understanding of mappings for transaction tables like purchase.