Index: lams_common/conf/hibernate/mappings/org/lamsfoundation/lams/tool/ToolSession.hbm.xml
===================================================================
diff -u -rd883255ed6c431a263a24462714bb62cfa7c6fa2 -ra71feb5790286722c6a32766ec76d3dc2e5b202f
--- lams_common/conf/hibernate/mappings/org/lamsfoundation/lams/tool/ToolSession.hbm.xml	(.../ToolSession.hbm.xml)	(revision d883255ed6c431a263a24462714bb62cfa7c6fa2)
+++ lams_common/conf/hibernate/mappings/org/lamsfoundation/lams/tool/ToolSession.hbm.xml	(.../ToolSession.hbm.xml)	(revision a71feb5790286722c6a32766ec76d3dc2e5b202f)
@@ -29,13 +29,13 @@
 
 		<discriminator column="tool_session_type_id" type="int" />
 
-		<property name="activityId" type="long" column="activity_id"
-			not-null="true" length="20">
-			<meta attribute="field-description">
-				@hibernate.property column="activity_id" length="20"
-				not-null="true"
-			</meta>
-		</property>
+		<!-- bi-directional many-to-one association to the tool activity -->
+		<many-to-one name="toolActivity"
+			class="org.lamsfoundation.lams.learningdesign.ToolActivity"
+			not-null="true">
+			<column name="activity_id" />
+		</many-to-one>
+
 		<property name="toolSessionKey" type="long"
 			column="tool_session_key" not-null="true" length="20">
 			<meta attribute="field-description">
Index: lams_common/src/java/org/lamsfoundation/lams/tool/ToolSession.java
===================================================================
diff -u -r6055275ce3f55b5d0f1ad4c4778f0316d9bd365f -ra71feb5790286722c6a32766ec76d3dc2e5b202f
--- lams_common/src/java/org/lamsfoundation/lams/tool/ToolSession.java	(.../ToolSession.java)	(revision 6055275ce3f55b5d0f1ad4c4778f0316d9bd365f)
+++ lams_common/src/java/org/lamsfoundation/lams/tool/ToolSession.java	(.../ToolSession.java)	(revision a71feb5790286722c6a32766ec76d3dc2e5b202f)
@@ -1,6 +1,8 @@
 package org.lamsfoundation.lams.tool;
 
 import org.lamsfoundation.lams.learningdesign.Group;
+import org.lamsfoundation.lams.learningdesign.ToolActivity;
+
 import java.io.Serializable;
 import java.util.Date;
 import java.util.Set;
@@ -32,7 +34,7 @@
     private Long toolSessionId;
 
     /** persistent field */
-    private long activityId;
+    private ToolActivity toolActivity;
 
     /** persistent field */
     private long toolSessionKey;
@@ -46,9 +48,9 @@
     private int toolSessionTypeId;
 
     /** full constructor */
-    public ToolSession(Long toolSessionId, long activityId, long toolSessionKey, Date createDateTime, Group group, int toolSessionStateId, Set userToolSessions) {
+    public ToolSession(Long toolSessionId, ToolActivity toolActivity, long toolSessionKey, Date createDateTime, Group group, int toolSessionStateId, Set userToolSessions) {
         this.toolSessionId = toolSessionId;
-        this.activityId = activityId;
+        this.toolActivity = toolActivity;
         this.toolSessionKey = toolSessionKey;
         this.createDateTime = createDateTime;
         this.toolSessionStateId = toolSessionStateId;
@@ -74,18 +76,16 @@
     }
 
     /** 
-     *            @hibernate.property
-     *             column="activity_id"
-     *             length="20"
-     *             not-null="true"
-     *         
+     * 
+     * @hibernate.many-to-one not-null="true"
+     * @hibernate.column name="activity_id"      
      */
-    public long getActivityId() {
-        return this.activityId;
+    public ToolActivity getToolActivity() {
+        return this.toolActivity;
     }
 
-    public void setActivityId(long activityId) {
-        this.activityId = activityId;
+    public void setToolActivity(ToolActivity toolActivity) {
+        this.toolActivity = toolActivity;
     }
 
     /**