<?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="tpos.Inventory" table="inventory"> 

       <id name="allocationId" type="int" column="AllocationId" > 
       <generator class="native"/> 
      </id> 
       
       
     <property name="allocatedLocation"> 
      <column name="AllocatedLocation"/> 
      </property> 
   
       
      <property name="sellable_Notsellable"> 
       <column name="Sellable_NotSellable"/> 
      </property> 
       
      <property name="sellablefromDate"> 
      <column  name="SellableFromDate" />   
      </property> 
       
      <property name="sellableTill"> 
      <column name="SellableTill" /> 
      </property> 
     
     
      <many-to-one name="productID" class="tpos.ProductInformation" column="productid" not-null="false" cascade="all" unique="true"  /> 

</class>
</hibernate-mapping>

    <?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="tpos.ProductInformation" table="ProductInformation" > 
       
       
       <id name="productId" type="int" column="ProductId" > 
       <generator class="native"/> 
      </id> 
       
      <property name="productCode"> 
      <column name="ProductCode"/> 
      </property> 
 
      <property name="productName"> 
       <column name="ProductName" /> 
      </property> 
       
      <property name="createdDate"> 
       <column name="CreatedDate"/> 
      </property> 
       
      <property name="expiryDate"> 
      <column  name="ExpiryDate" />   
      </property> 
       
      <property name="statuS"> 
      <column name="Status" /> 
      </property> 
       
       
      <property name="sellablE"> 
      <column name="Sellable" /> 
      </property> 
     
       
      <property name="purchaseDate"> 
      <column name="PurchaseDate" /> 
      </property> 
       
      <property name="barcodeNo"> 
      <column name="BarcodeNo" /> 
      </property> 
       
      <property name="updationDate"> 
      <column name="UpdationDate" /> 
      </property> 
       
      <property name="createdBy"> 
      <column name="CreatedBy" /> 
      </property> 
       
      <property name="updatedBy"> 
      <column name="UpdatedBy" /> 
      </property> 
       
      <property name="productCompType"> 
      <column name="ProductCompType" /> 
      </property> 
     </class> 
    </hibernate-mapping> 

<many-to-one name="productID" ...

from Inventory inv join inv.productID pi

select inv fromInventory inv

select inv fromInventory inv join fetch inv.productID

private ProductInformation pi;
public void setProductID(ProductInformation pi) {
  this.pi = pi;
}
public ProductInformation getProductID() {
   return pi;
}