diff --git a/group/db/install.xml b/group/db/install.xml
index f4d5cac4822..c7de130adf5 100644
--- a/group/db/install.xml
+++ b/group/db/install.xml
@@ -4,7 +4,7 @@
     xsi:noNamespaceSchemaLocation="../../lib/xmldb/xmldb.xsd"
 >
   <TABLES>
-    <TABLE NAME="groups" COMMENT="Each record represents a group." NEXT="groups_members">
+    <TABLE NAME="groups" COMMENT="Each record represents a group." NEXT="groups_groupings">
       <FIELDS>
         <FIELD NAME="id" TYPE="int" LENGTH="10" NOTNULL="true" UNSIGNED="true" SEQUENCE="true" ENUM="false" NEXT="name"/>
         <FIELD NAME="name" TYPE="char" LENGTH="254" NOTNULL="true" SEQUENCE="false" ENUM="false" COMMENT="Short human readable unique name for the group." PREVIOUS="id" NEXT="description"/>
@@ -21,22 +21,7 @@
         <KEY NAME="primary" TYPE="primary" FIELDS="id" COMMENT="Primary key for groups"/>
       </KEYS>
     </TABLE>
-    <TABLE NAME="groups_members" COMMENT="Link a user to a group." PREVIOUS="groups" NEXT="groups_groupings">
-      <FIELDS>
-        <FIELD NAME="id" TYPE="int" LENGTH="10" NOTNULL="true" UNSIGNED="true" SEQUENCE="true" ENUM="false" NEXT="groupid"/>
-        <FIELD NAME="groupid" TYPE="int" LENGTH="10" NOTNULL="true" UNSIGNED="true" DEFAULT="0" SEQUENCE="false" ENUM="false" PREVIOUS="id" NEXT="userid"/>
-        <FIELD NAME="userid" TYPE="int" LENGTH="10" NOTNULL="true" UNSIGNED="true" DEFAULT="0" SEQUENCE="false" ENUM="false" PREVIOUS="groupid" NEXT="timeadded"/>
-        <FIELD NAME="timeadded" TYPE="int" LENGTH="10" NOTNULL="true" UNSIGNED="true" DEFAULT="0" SEQUENCE="false" ENUM="false" PREVIOUS="userid"/>
-      </FIELDS>
-      <KEYS>
-        <KEY NAME="primary" TYPE="primary" FIELDS="id" COMMENT="Primary key for groups_members"/>
-      </KEYS>
-      <INDEXES>
-        <INDEX NAME="groupid" UNIQUE="false" FIELDS="groupid" NEXT="userid"/>
-        <INDEX NAME="userid" UNIQUE="false" FIELDS="userid" PREVIOUS="groupid"/>
-      </INDEXES>
-    </TABLE>
-    <TABLE NAME="groups_groupings" COMMENT="A grouping is a collection of groups." PREVIOUS="groups_members" NEXT="groups_courses_groups">
+    <TABLE NAME="groups_groupings" COMMENT="A grouping is a collection of groups." PREVIOUS="groups" NEXT="groups_members">
       <FIELDS>
         <FIELD NAME="id" TYPE="int" LENGTH="10" NOTNULL="true" UNSIGNED="false" SEQUENCE="true" ENUM="false" COMMENT="id of the table, please edit me" NEXT="name"/>
         <FIELD NAME="name" TYPE="char" LENGTH="255" NOTNULL="true" SEQUENCE="false" ENUM="false" COMMENT="Short human readable unique name for group." PREVIOUS="id" NEXT="description"/>
@@ -54,15 +39,36 @@
         <KEY NAME="primary" TYPE="primary" FIELDS="id" COMMENT="Primary key for groups_groupings"/>
       </KEYS>
     </TABLE>
-    <TABLE NAME="groups_courses_groups" COMMENT="Link a group to a course (or the site)." PREVIOUS="groups_groupings" NEXT="groups_courses_groupings">
+    <TABLE NAME="groups_members" COMMENT="Link a user to a group." PREVIOUS="groups_groupings" NEXT="groups_courses_groups">
+      <FIELDS>
+        <FIELD NAME="id" TYPE="int" LENGTH="10" NOTNULL="true" UNSIGNED="true" SEQUENCE="true" ENUM="false" NEXT="groupid"/>
+        <FIELD NAME="groupid" TYPE="int" LENGTH="10" NOTNULL="true" UNSIGNED="true" DEFAULT="0" SEQUENCE="false" ENUM="false" PREVIOUS="id" NEXT="userid"/>
+        <FIELD NAME="userid" TYPE="int" LENGTH="10" NOTNULL="true" UNSIGNED="true" DEFAULT="0" SEQUENCE="false" ENUM="false" PREVIOUS="groupid" NEXT="timeadded"/>
+        <FIELD NAME="timeadded" TYPE="int" LENGTH="10" NOTNULL="true" UNSIGNED="true" DEFAULT="0" SEQUENCE="false" ENUM="false" PREVIOUS="userid"/>
+      </FIELDS>
+      <KEYS>
+        <KEY NAME="primary" TYPE="primary" FIELDS="id" COMMENT="Primary key for groups_members" NEXT="groupid"/>
+        <KEY NAME="groupid" TYPE="foreign" FIELDS="groupid" REFTABLE="groups" REFFIELDS="id" PREVIOUS="primary" NEXT="userid"/>
+        <KEY NAME="userid" TYPE="foreign" FIELDS="userid" REFTABLE="user" REFFIELDS="id" PREVIOUS="groupid"/>
+      </KEYS>
+      <INDEXES>
+        <INDEX NAME="groupid-courseid" UNIQUE="true" FIELDS="groupid, userid"/>
+      </INDEXES>
+    </TABLE>
+    <TABLE NAME="groups_courses_groups" COMMENT="Link a group to a course (or the site)." PREVIOUS="groups_members" NEXT="groups_courses_groupings">
       <FIELDS>
         <FIELD NAME="id" TYPE="int" LENGTH="10" NOTNULL="true" UNSIGNED="false" SEQUENCE="true" ENUM="false" COMMENT="id of the table, please edit me" NEXT="courseid"/>
         <FIELD NAME="courseid" TYPE="int" LENGTH="10" NOTNULL="true" UNSIGNED="true" DEFAULT="0" SEQUENCE="false" ENUM="false" PREVIOUS="id" NEXT="groupid"/>
         <FIELD NAME="groupid" TYPE="int" LENGTH="10" NOTNULL="true" UNSIGNED="true" SEQUENCE="false" ENUM="false" COMMENT="Default comment for the field, please edit me" PREVIOUS="courseid"/>
       </FIELDS>
       <KEYS>
-        <KEY NAME="primary" TYPE="primary" FIELDS="id" COMMENT="Primary key for groups_courses_groups"/>
+        <KEY NAME="primary" TYPE="primary" FIELDS="id" COMMENT="Primary key for groups_courses_groups" NEXT="courseid"/>
+        <KEY NAME="courseid" TYPE="foreign" FIELDS="courseid" REFTABLE="course" REFFIELDS="id" PREVIOUS="primary" NEXT="groupid"/>
+        <KEY NAME="groupid" TYPE="foreign" FIELDS="groupid" REFTABLE="groups" REFFIELDS="id" PREVIOUS="courseid"/>
       </KEYS>
+      <INDEXES>
+        <INDEX NAME="courseid-groupid" UNIQUE="true" FIELDS="courseid, groupid"/>
+      </INDEXES>
     </TABLE>
     <TABLE NAME="groups_courses_groupings" COMMENT="Link a grouping to a course (or the site)." PREVIOUS="groups_courses_groups" NEXT="groups_groupings_groups">
       <FIELDS>
@@ -71,8 +77,13 @@
         <FIELD NAME="groupingid" TYPE="int" LENGTH="10" NOTNULL="true" UNSIGNED="true" SEQUENCE="false" ENUM="false" PREVIOUS="courseid"/>
       </FIELDS>
       <KEYS>
-        <KEY NAME="primary" TYPE="primary" FIELDS="id" COMMENT="Primary key for groups_courses_groupings"/>
+        <KEY NAME="primary" TYPE="primary" FIELDS="id" COMMENT="Primary key for groups_courses_groupings" NEXT="courseid"/>
+        <KEY NAME="courseid" TYPE="foreign" FIELDS="courseid" REFTABLE="course" REFFIELDS="id" PREVIOUS="primary" NEXT="groupingid"/>
+        <KEY NAME="groupingid" TYPE="foreign" FIELDS="groupingid" REFTABLE="groups_groupings" REFFIELDS="id" PREVIOUS="courseid"/>
       </KEYS>
+      <INDEXES>
+        <INDEX NAME="courseid-groupingid" UNIQUE="true" FIELDS="courseid, groupingid"/>
+      </INDEXES>
     </TABLE>
     <TABLE NAME="groups_groupings_groups" COMMENT="Link a group to a grouping." PREVIOUS="groups_courses_groupings">
       <FIELDS>
@@ -82,8 +93,13 @@
         <FIELD NAME="timeadded" TYPE="int" LENGTH="10" NOTNULL="true" UNSIGNED="true" DEFAULT="0" SEQUENCE="false" ENUM="false" PREVIOUS="groupid"/>
       </FIELDS>
       <KEYS>
-        <KEY NAME="primary" TYPE="primary" FIELDS="id" COMMENT="Primary key for groups_groupings_groups"/>
+        <KEY NAME="primary" TYPE="primary" FIELDS="id" COMMENT="Primary key for groups_groupings_groups" NEXT="groupingid"/>
+        <KEY NAME="groupingid" TYPE="foreign" FIELDS="groupingid" REFTABLE="groups_groupings" REFFIELDS="id" PREVIOUS="primary" NEXT="groupid"/>
+        <KEY NAME="groupid" TYPE="foreign" FIELDS="groupid" REFTABLE="groups" REFFIELDS="id" PREVIOUS="groupingid"/>
       </KEYS>
+      <INDEXES>
+        <INDEX NAME="groupingid-groupid" UNIQUE="true" FIELDS="groupingid, groupid"/>
+      </INDEXES>
     </TABLE>
   </TABLES>
   <STATEMENTS>
diff --git a/group/db/upgrade.php b/group/db/upgrade.php
index d9dcb25139a..6702e06b886 100644
--- a/group/db/upgrade.php
+++ b/group/db/upgrade.php
@@ -241,6 +241,90 @@ function xmldb_group_upgrade($oldversion=0) {
         $result = $result && change_field_precision($table, $field);
     }
 
+    /// Adding all the missing FK + Unique indexes (XMLDB will create the underlying indexes)
+    if ($result && $oldversion < 2007012200) {
+
+    /// Define index groupid-courseid (unique) to be added to groups_members
+        $table = new XMLDBTable('groups_members');
+        $index = new XMLDBIndex('groupid-courseid');
+        $index->setAttributes(XMLDB_INDEX_UNIQUE, array('groupid', 'userid'));
+
+    /// Launch add index groupid-courseid
+        $result = $result && add_index($table, $index);
+
+    /// Define key courseid (foreign) to be added to groups_courses_groups
+        $table = new XMLDBTable('groups_courses_groups');
+        $key = new XMLDBKey('courseid');
+        $key->setAttributes(XMLDB_KEY_FOREIGN, array('courseid'), 'course', array('id'));
+
+    /// Launch add key courseid
+        $result = $result && add_key($table, $key);
+
+    /// Define key groupid (foreign) to be added to groups_courses_groups
+        $table = new XMLDBTable('groups_courses_groups');
+        $key = new XMLDBKey('groupid');
+        $key->setAttributes(XMLDB_KEY_FOREIGN, array('groupid'), 'groups', array('id'));
+
+    /// Launch add key groupid
+        $result = $result && add_key($table, $key);
+
+    /// Define index courseid-groupid (unique) to be added to groups_courses_groups
+        $table = new XMLDBTable('groups_courses_groups');
+        $index = new XMLDBIndex('courseid-groupid');
+        $index->setAttributes(XMLDB_INDEX_UNIQUE, array('courseid', 'groupid'));
+
+    /// Launch add index courseid-groupid
+        $result = $result && add_index($table, $index);
+
+    /// Define key courseid (foreign) to be added to groups_courses_groupings
+        $table = new XMLDBTable('groups_courses_groupings');
+        $key = new XMLDBKey('courseid');
+        $key->setAttributes(XMLDB_KEY_FOREIGN, array('courseid'), 'course', array('id'));
+
+    /// Launch add key courseid
+        $result = $result && add_key($table, $key);
+
+    /// Define key groupingid (foreign) to be added to groups_courses_groupings
+        $table = new XMLDBTable('groups_courses_groupings');
+        $key = new XMLDBKey('groupingid');
+        $key->setAttributes(XMLDB_KEY_FOREIGN, array('groupingid'), 'groups_groupings', array('id'));
+
+    /// Launch add key groupingid
+        $result = $result && add_key($table, $key);
+
+    /// Define index courseid-groupingid (unique) to be added to groups_courses_groupings
+        $table = new XMLDBTable('groups_courses_groupings');
+        $index = new XMLDBIndex('courseid-groupingid');
+        $index->setAttributes(XMLDB_INDEX_UNIQUE, array('courseid', 'groupingid'));
+
+    /// Launch add index courseid-groupingid
+        $result = $result && add_index($table, $index);
+
+    /// Define key groupingid (foreign) to be added to groups_groupings_groups
+        $table = new XMLDBTable('groups_groupings_groups');
+        $key = new XMLDBKey('groupingid');
+        $key->setAttributes(XMLDB_KEY_FOREIGN, array('groupingid'), 'groups_groupings', array('id'));
+
+    /// Launch add key groupingid
+        $result = $result && add_key($table, $key);
+
+    /// Define key groupid (foreign) to be added to groups_groupings_groups
+        $table = new XMLDBTable('groups_groupings_groups');
+        $key = new XMLDBKey('groupid');
+        $key->setAttributes(XMLDB_KEY_FOREIGN, array('groupid'), 'groups', array('id'));
+
+    /// Launch add key groupid
+        $result = $result && add_key($table, $key);
+
+    /// Define index groupingid-groupid (unique) to be added to groups_groupings_groups
+        $table = new XMLDBTable('groups_groupings_groups');
+        $index = new XMLDBIndex('groupingid-groupid');
+        $index->setAttributes(XMLDB_INDEX_UNIQUE, array('groupingid', 'groupid'));
+
+    /// Launch add index groupingid-groupid
+        $result = $result && add_index($table, $index);
+    }
+
     return $result;
 }
 
diff --git a/group/version.php b/group/version.php
index 83d23853e2e..0a0650fc9c1 100644
--- a/group/version.php
+++ b/group/version.php
@@ -5,7 +5,7 @@
 //  This fragment is called by /admin/index.php
 ////////////////////////////////////////////////////////////////////////////////
 
-$group_version  = 2007012100;
+$group_version  = 2007012200;
 //$module->requires = 2006120400;  // Requires this Moodle version
 
 ?>