Index: lams_common/conf/hibernate/mappings/org/lamsfoundation/lams/tool/ToolSession.hbm.xml
===================================================================
diff -u -r53f5c22785cd5d9d63e6c1557f460ba7314635e5 -reb7cd8dc081b796b5f059b7a6bcf8d7124488d6f
--- lams_common/conf/hibernate/mappings/org/lamsfoundation/lams/tool/ToolSession.hbm.xml	(.../ToolSession.hbm.xml)	(revision 53f5c22785cd5d9d63e6c1557f460ba7314635e5)
+++ lams_common/conf/hibernate/mappings/org/lamsfoundation/lams/tool/ToolSession.hbm.xml	(.../ToolSession.hbm.xml)	(revision eb7cd8dc081b796b5f059b7a6bcf8d7124488d6f)
@@ -29,13 +29,20 @@
 
 		<discriminator column="tool_session_type_id" type="int" />
 
-		<!-- bi-directional many-to-one association to the tool activity -->
+		<!-- uni-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>
 
+		<!-- uni-directional many-to-one association to the tool lesson -->
+		<many-to-one name="lesson"
+			class="org.lamsfoundation.lams.lesson.Lesson"
+			not-null="true">
+			<column name="lesson_id" />
+		</many-to-one>
+
 		<property name="createDateTime" type="java.sql.Timestamp"
 			column="create_date_time" not-null="true" length="19">
 			<meta attribute="field-description">