Multiple primary key

njel_valdez · **Posted:** Wed Apr 11, 2007 6:02 am

hi,
i'm looking for sample application that shows how to map multiple primary key.i am mapping a table that has two primary key these are the following fields :
computer_id, user_id
thanks in advance.

njel_valdez · **Posted:** Wed Apr 11, 2007 9:48 pm

njel_valdez wrote:

hi,
i'm looking for sample application that shows how to map multiple primary key.i am mapping a table that has two primary key these are the following fields :
computer_id, user_id
thanks in advance.

i was reading the nhibernate reference material and i found the solution to my problem.here is the sample hbm.xml file. i use the <composite-id> to tag multiple primary keys.

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.0">
<class name="WindowsApplication1.User, WindowsApplication1" table="users">
<composite-id>
<key-property name="Id" column="Computer_id" type="String" length="20"/>
<key-property name="UserID" column="user_id" type="String" length="40"/>
</composite-id>
<property name="Password" type="String" length="20"/>
<property name="EmailAddress" type="String" length="40"/>
<property name="LastLogon" type="DateTime"/>
</class>
</hibernate-mapping>

surfrider890 · **Joined:** Mon Apr 16, 2007 3:20 pm **Posts:** 7

Hi, Is it this simple. I'm pretty sure I've tried this, but am having such problems getting a composite-id to work. My composite id is made up of 4 fields. Does that mean i need to do anything different?

Also, are there special wrappers or tags i need to place is the class file? Thanks for your help. I've really been struggling with this for a day or two now, and dont' know what to do. Thanks a lot. Here's my mapping just in case ( I have 3 different versions of it, bcz I've seen so many different examples, but here is the latest):

Code:

<?xml version="1.0" encoding="utf-8" ?> 
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
   <class name="EmployeeTimeTracker.EmpTime, EmployeeTimeTracker" table="dbo.EMPLOYEE_TIME_USED">
      <composite-id>      
          <key-many-to-one name="EmpID" column="EMPLOYEEID" type="String" length="50" />                   
         <key-many-to-one name="TimeType" column="TIME_ID" type="String" length="1" />                  
         <key-many-to-one name="AttendReason" column="REASON_ID" type="Integer" />                  
         <key-property name="DateUsed" column="DATE_USED" type="DateTime" />                             
      </composite-id>
                  
      <property name="HoursUsed" column="HOURS_USED" type="Double" />   
      
      <many-to-one name="EmpID" class="EmployeeTimeTracker.Employee, EmployeeTimeTracker">
         <column name="EMPLOYEEID" />
      </many-to-one>
      <many-to-one name="TimeType" class="EmployeeTimeTracker.TimeType, EmployeeTimeTracker">
         <column name="TIME_ID" />
      </many-to-one>
      <many-to-one name="AttendReason" class="EmployeeTimeTracker.AttendReason, EmployeeTimeTracker">
         <column name="REASON_ID" />
      </many-to-one>
   </class>
</hibernate-mapping>