accoding the hibernate manual,write the parent-child xml mapping file, in the parent.hbm.xml,the set tag using the lazy property .

when using the session.find(query,object[],type[]) to select the child object, watching the logging,it display that hibernate also select the parent record,if so,if child has foreign relation with other table ,it will load these record?I think it should avoid,but I don't how to do it?

thks

show parent + child mapping files

the parent.xml is:
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 2.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd" >

<hibernate-mapping>
<!--
Created by the Middlegen Hibernate plugin

http://boss.bekk.no/boss/middlegen/
http://hibernate.sourceforge.net/
-->

<class
name="com.zte.cdma.u100.po.Parent"
table="PARENT"
>

<id
name="parentId"
type="java.lang.Long"
column="PARENT_ID"
>
<generator class="assigned" />
</id>

<property
name="name"
type="java.lang.String"
column="NAME"
not-null="true"
length="10"
/>
<property
name="address"
type="java.lang.String"
column="ADDRESS"
not-null="true"
length="10"
/>

<!-- associations -->
<!-- bi-directional one-to-many association to Child -->
<set
name="childs"
lazy="true"
inverse="true"
>
<key>
<column name="PARENT_ID" />
</key>
<one-to-many
class="com.zte.cdma.u100.po.Child"
/>
</set>

</class>
</hibernate-mapping>

the child xml is:

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 2.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd" >

<hibernate-mapping>
<!--
Created by the Middlegen Hibernate plugin

http://boss.bekk.no/boss/middlegen/
http://hibernate.sourceforge.net/
-->

<class
name="com.zte.cdma.u100.po.Child"
table="CHILD"
>

<id
name="childId"
type="java.lang.Long"
column="CHILD_ID"
>
<generator class="assigned" />
</id>

<property
name="name"
type="java.lang.String"
column="NAME"
not-null="true"
length="10"
/>

<!-- associations -->
<!-- bi-directional many-to-one association to Parent -->
<many-to-one
name="parent"
class="com.zte.cdma.u100.po.Parent"
not-null="true"
>
<column name="PARENT_ID" />
</many-to-one>

</class>
</hibernate-mapping>

with your mapping, the child collection is lazy, not the parent
change
<class
name="com.zte.cdma.u100.po.Parent"
table="PARENT"
>

to

<class
name="com.zte.cdma.u100.po.Parent"
table="PARENT" lazy="true"
>

you'll need a default constructor, read the doc about this

I didn't know this little tick. Thanks Anthony!