diff --git a/lib/db/upgrade.php b/lib/db/upgrade.php
index 15aad8923a2..4209b7c7401 100644
--- a/lib/db/upgrade.php
+++ b/lib/db/upgrade.php
@@ -1047,6 +1047,8 @@ function xmldb_main_upgrade($oldversion) {
     }
 
     if ($oldversion < 2009010602) {
+        // Issue with field in the user table being null in postgres.
+        $DB->execute("UPDATE {user} SET lastip = '' WHERE lastip IS NULL");
 
     /// Changing precision of field lastip on table user to (45)
         $table = new xmldb_table('user');
@@ -4736,6 +4738,10 @@ WHERE gradeitemid IS NOT NULL AND grademax IS NOT NULL");
         if ($dbman->index_exists($table, $index)) {
             $dbman->drop_index($table, $index);
         }
+
+        // Issue with field in the user table being null in postgres.
+        $DB->execute("UPDATE {user} SET city = '' WHERE city IS NULL");
+
     /// Changing precision of field city on table user to (120)
         $field = new xmldb_field('city', XMLDB_TYPE_CHAR, '120', null, XMLDB_NOTNULL, null, null, 'address');
 
@@ -6821,5 +6827,87 @@ FROM
         upgrade_main_savepoint(true,2011070106.03);
     }
 
+    if ($oldversion < 2011070108.08) {
+        // Issue with Moodle version < 1.7 using postgres having null values in the user table.
+        if ($DB->get_dbfamily() === 'postgres') {
+            // Array to store columns we may need to change.
+            $arrcolumns = array('idnumber', 'icq', 'skype', 'yahoo', 'aim', 'msn',
+                                'phone1', 'phone2', 'institution', 'department',
+                                'address', 'city', 'country', 'lastip', 'secret',
+                                'picture', 'url');
+            // OK, now we want to remove the columns that already have the default values before editing.
+            $columns = $DB->get_columns('user');
+            foreach ($columns as $c) {
+                if (in_array($c->name, $arrcolumns)) {
+                    if ($c->has_default && $c->not_null) {
+                        $arrcolumns = array_diff($arrcolumns, array($c->name));
+                    } else {
+                        if ($c->name == 'picture') {
+                            $DB->execute("UPDATE {user} SET picture = '0' WHERE picture IS NULL");
+                        } else {
+                            $DB->execute("UPDATE {user} SET $c->name = '' WHERE $c->name IS NULL");
+                        }
+                    }
+                }
+            }
+            // Create user table object.
+            $table = new xmldb_table('user');
+            // Create array to store the indexes in the user table.
+            $arrindexes = array();
+            $arrindexes['idnumber'] = new xmldb_index('idnumber', XMLDB_INDEX_NOTUNIQUE, array('idnumber'));
+            $arrindexes['city'] = new xmldb_index('city', XMLDB_INDEX_NOTUNIQUE, array('city'));
+            $arrindexes['country'] = new xmldb_index('country', XMLDB_INDEX_NOTUNIQUE, array('country'));
+            // Loop through the indexes.
+            foreach ($arrindexes as $key => $index) {
+                // Check if it is not in the columns array and remove as it does not need editing.
+                if (!in_array($key, $arrcolumns)) {
+                    unset($arrindexes[$key]);
+                }
+            }
+            // Remove the indexes that need to be removed.
+            foreach ($arrindexes as $index) {
+                if ($dbman->index_exists($table, $index)) {
+                    $dbman->drop_index($table, $index);
+                }
+            }
+            // Create list of fields that potentially need changed.
+            $arrfields = array();
+            $arrfields['idnumber'] = new xmldb_field('idnumber', XMLDB_TYPE_CHAR, '255', null, XMLDB_NOTNULL, null, null, 'password');
+            $arrfields['icq'] = new xmldb_field('icq', XMLDB_TYPE_CHAR, '15', null, XMLDB_NOTNULL, null, null, 'emailstop');
+            $arrfields['skype'] = new xmldb_field('skype', XMLDB_TYPE_CHAR, '50', null, XMLDB_NOTNULL, null, null, 'icq');
+            $arrfields['yahoo'] = new xmldb_field('yahoo', XMLDB_TYPE_CHAR, '50', null, XMLDB_NOTNULL, null, null, 'skype');
+            $arrfields['aim'] = new xmldb_field('aim', XMLDB_TYPE_CHAR, '50', null, XMLDB_NOTNULL, null, null, 'yahoo');
+            $arrfields['msn'] = new xmldb_field('msn', XMLDB_TYPE_CHAR, '50', null, XMLDB_NOTNULL, null, null, 'aim');
+            $arrfields['phone1'] = new xmldb_field('phone1', XMLDB_TYPE_CHAR, '20', null, XMLDB_NOTNULL, null, null, 'msn');
+            $arrfields['phone2'] = new xmldb_field('phone2', XMLDB_TYPE_CHAR, '20', null, XMLDB_NOTNULL, null, null, 'phone1');
+            $arrfields['institution'] = new xmldb_field('institution', XMLDB_TYPE_CHAR, '40', null, XMLDB_NOTNULL, null, null, 'phone2');
+            $arrfields['department'] = new xmldb_field('department', XMLDB_TYPE_CHAR, '30', null, XMLDB_NOTNULL, null, null, 'institution');
+            $arrfields['address'] = new xmldb_field('address', XMLDB_TYPE_CHAR, '70', null, XMLDB_NOTNULL, null, null, 'department');
+            $arrfields['city'] = new xmldb_field('city', XMLDB_TYPE_CHAR, '120', null, XMLDB_NOTNULL, null, null, 'address');
+            $arrfields['country'] = new xmldb_field('country', XMLDB_TYPE_CHAR, '2', null, XMLDB_NOTNULL, null, null, 'city');
+            $arrfields['lastip'] = new xmldb_field('lastip', XMLDB_TYPE_CHAR, '45', null, XMLDB_NOTNULL, null, null, 'country');
+            $arrfields['secret'] = new xmldb_field('secret', XMLDB_TYPE_CHAR, '15', null, XMLDB_NOTNULL, null, null, 'lastip');
+            $arrfields['picture'] = new xmldb_field('picture', XMLDB_TYPE_INTEGER, '1', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, 0, 'secret');
+            $arrfields['url'] = new xmldb_field('url', XMLDB_TYPE_CHAR, '255', null, XMLDB_NOTNULL, null, null, 'picture');
+            foreach ($arrfields as $key => $field) {
+                // If it is in the columns array it needs editing.
+                if (in_array($key, $arrcolumns)) {
+                    if ($dbman->field_exists($table, $field)) {
+                        $dbman->change_field_notnull($table, $field);
+                    }
+                }
+            }
+            // Re-add the indexes that were removed.
+            foreach ($arrindexes as $index) {
+                if (!$dbman->index_exists($table, $index)) {
+                    $dbman->add_index($table, $index);
+                }
+            }
+        }
+
+        // Main savepoint reached.
+        upgrade_main_savepoint(true, 2011070108.08);
+    }
+
     return true;
 }