Index: openacs-4/packages/adserver/tcl/adserver-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/adserver/tcl/adserver-procs.tcl,v
diff -u -N -r1.6 -r1.7
--- openacs-4/packages/adserver/tcl/adserver-procs.tcl	29 Mar 2018 15:03:00 -0000	1.6
+++ openacs-4/packages/adserver/tcl/adserver-procs.tcl	12 Feb 2019 18:00:04 -0000	1.7
@@ -278,7 +278,7 @@
             } [adserver_cache_refresh]]} {
                 set user_id [ad_get_user_id]
                 if {$user_id == 0} {
-                    set user_id [db_null]
+                    set user_id ""
                 }
                 # ignore logged out clicks, for now....
                 db_dml adserver_defs_adv_user_insert {
Index: openacs-4/packages/adserver/www/adhref.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/adserver/www/adhref.tcl,v
diff -u -N -r1.3 -r1.4
--- openacs-4/packages/adserver/www/adhref.tcl	18 Sep 2002 12:11:28 -0000	1.3
+++ openacs-4/packages/adserver/www/adhref.tcl	12 Feb 2019 18:00:04 -0000	1.4
@@ -89,7 +89,7 @@
     } [adserver_cache_refresh]] {
     set user_id [ad_get_user_id]
     if { $user_id == 0 } {
-        set user_id [db_null]
+        set user_id ""
     } 
     # we know who this user is
     db_dml adv_known_user_insert "
Index: openacs-4/packages/adserver/www/adimg.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/adserver/www/adimg.tcl,v
diff -u -N -r1.3 -r1.4
--- openacs-4/packages/adserver/www/adimg.tcl	18 Sep 2002 12:11:28 -0000	1.3
+++ openacs-4/packages/adserver/www/adimg.tcl	12 Feb 2019 18:00:04 -0000	1.4
@@ -121,7 +121,7 @@
     } [adserver_cache_refresh]] {
         set user_id [ad_get_user_id]
         if { $user_id == 0 } {
-            set user_id [db_null]
+            set user_id ""
         } 
         # we know who this user is
         db_dml adv_known_user_insert "
Index: openacs-4/packages/download/tcl/download-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/download/tcl/download-procs.tcl,v
diff -u -N -r1.19 -r1.20
--- openacs-4/packages/download/tcl/download-procs.tcl	29 Mar 2018 21:47:00 -0000	1.19
+++ openacs-4/packages/download/tcl/download-procs.tcl	12 Feb 2019 18:00:04 -0000	1.20
@@ -132,7 +132,7 @@
     if [catch {
         set download_hostname [ns_hostbyaddr $download_ip]
     }] {
-        set download_hostname [db_null]
+        set download_hostname ""
     }
     set user_agent  [ns_set iget [ad_conn headers] user-agent]
 
Index: openacs-4/packages/download/www/archive-add-2.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/download/www/archive-add-2.tcl,v
diff -u -N -r1.9 -r1.10
--- openacs-4/packages/download/www/archive-add-2.tcl	20 Jan 2018 22:42:17 -0000	1.9
+++ openacs-4/packages/download/www/archive-add-2.tcl	12 Feb 2019 18:00:04 -0000	1.10
@@ -32,10 +32,10 @@
 # check for write permission on this repository
 permission::require_permission -object_id $repository_id -privilege write
 
-set approved_p [ad_decode $admin_p 0 [db_null] "t"]
-set approved_date [ad_decode $admin_p 0 [db_null] "sysdate"]
-set approved_user [ad_decode $admin_p 0 [db_null] ":user_id"]
-set approved_comment [ad_decode $admin_p 0 [db_null] "Automatic approval, add by admin."]
+set approved_p [ad_decode $admin_p 0 "" "t"]
+set approved_date [ad_decode $admin_p 0 "" "sysdate"]
+set approved_user [ad_decode $admin_p 0 "" ":user_id"]
+set approved_comment [ad_decode $admin_p 0 "" "Automatic approval, add by admin."]
 
 # get the ip
 set creation_ip [ad_conn peeraddr]
Index: openacs-4/packages/download/www/archive-version-add-2.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/download/www/archive-version-add-2.tcl,v
diff -u -N -r1.4 -r1.5
--- openacs-4/packages/download/www/archive-version-add-2.tcl	6 Aug 2014 16:24:41 -0000	1.4
+++ openacs-4/packages/download/www/archive-version-add-2.tcl	12 Feb 2019 18:00:04 -0000	1.5
@@ -29,10 +29,10 @@
 # check for write permission on this folder
 permission::require_permission -object_id $archive_id -privilege write
 
-set approved_p [ad_decode $admin_p 0 [db_null] "t"]
-set approved_date [ad_decode $admin_p 0 [db_null] "sysdate"]
-set approved_user [ad_decode $admin_p 0 [db_null] ":user_id"]
-set approved_comment [ad_decode $admin_p 0 [db_null] "Automatic approval, add by admin."]
+set approved_p [ad_decode $admin_p 0 "" "t"]
+set approved_date [ad_decode $admin_p 0 "" "sysdate"]
+set approved_user [ad_decode $admin_p 0 "" ":user_id"]
+set approved_comment [ad_decode $admin_p 0 "" "Automatic approval, add by admin."]
 
 
 # get the ip
@@ -43,4 +43,4 @@
     download_insert_revision $upload_file ${upload_file.tmpfile} $repository_id $archive_type_id $archive_id $version_name $revision_id $user_id $creation_ip $approved_p [array get metadata]
 }
 
-ad_returnredirect $return_url
\ No newline at end of file
+ad_returnredirect $return_url
Index: openacs-4/packages/download/www/admin/approve-or-reject-2.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/download/www/admin/approve-or-reject-2.tcl,v
diff -u -N -r1.10 -r1.11
--- openacs-4/packages/download/www/admin/approve-or-reject-2.tcl	20 Jan 2018 22:42:17 -0000	1.10
+++ openacs-4/packages/download/www/admin/approve-or-reject-2.tcl	12 Feb 2019 18:00:04 -0000	1.11
@@ -7,7 +7,7 @@
 } {
     action:notnull
     revision_id:naturalnum,notnull
-    { approved_comment [db_null] }
+    { approved_comment "" }
     {return_url "[ad_conn package_url]"}
 } -validate {
     valid_action_value {
Index: openacs-4/packages/dynamic-types/tcl/dynamic-type-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/dynamic-types/tcl/dynamic-type-procs.tcl,v
diff -u -N -r1.12 -r1.13
--- openacs-4/packages/dynamic-types/tcl/dynamic-type-procs.tcl	9 May 2018 15:33:31 -0000	1.12
+++ openacs-4/packages/dynamic-types/tcl/dynamic-type-procs.tcl	12 Feb 2019 18:00:04 -0000	1.13
@@ -113,10 +113,6 @@
     Creates a content type with consolidated view (see plpgsql function 
     dynamic_type__create_type).
 } {
-    if {[string equal $name_method ""]} {
-        set name_method [db_null]
-    }
-
     ns_log Debug "DYNAMIC TYPES: Creating Object $name with Pretty Name $pretty_name"
     db_exec_plsql create_type {}
 }
@@ -157,18 +153,6 @@
 } {
     Creates an attribute on a content type.
 } {
-    if {[string equal $pretty_plural ""]} {
-        set pretty_plural [db_null]
-    }
-
-    if {[string equal $sort_order ""]} {
-        set sort_order [db_null]
-    }
-
-    if {[string equal $default_value ""]} {
-        set default_value [db_null]
-    }
-    
     if {![db_0or1row select_column_spec {}]} {
         set column_spec ""
     }
Index: openacs-4/packages/dynamic-types/tcl/form-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/dynamic-types/tcl/form-procs.tcl,v
diff -u -N -r1.19 -r1.20
--- openacs-4/packages/dynamic-types/tcl/form-procs.tcl	9 May 2018 15:33:31 -0000	1.19
+++ openacs-4/packages/dynamic-types/tcl/form-procs.tcl	12 Feb 2019 18:00:04 -0000	1.20
@@ -206,19 +206,19 @@
 	set default(creation_ip) [ad_conn peeraddr]
     }
     if {![info exists default(context_id)]} {
-	set default(context_id) [db_null]
+	set default(context_id) ""
     }
     if {![info exists default(package_id)]} {
 	set default(package_id) [ad_conn package_id]
     }
     if {![info exists default(parent_id)]} {
-	set default(parent_id) [db_null]
+	set default(parent_id) ""
     }
     if {![info exists default(nls_language)]} {
-	set default(nls_language) [db_null]
+	set default(nls_language) ""
     }
     if {![info exists default(publish_date)]} {
-	set default(publish_date) [db_null]
+	set default(publish_date) ""
     }
     
     #######################################################
@@ -236,10 +236,10 @@
 
             array set item_defaults [list item_id $item_id \
                                          name "item$item_id" \
-                                         locale [db_null] \
-                                         parent_id [db_null] \
+                                         locale "" \
+                                         parent_id "" \
                                          content_type $object_type \
-                                         context_id [db_null] \
+                                         context_id "" \
                                          package_id [ad_conn package_id] \
                                          creation_user [ad_conn user_id] \
                                          creation_ip [ad_conn peeraddr] \
Index: openacs-4/packages/glossar/tcl/glossar-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/glossar/tcl/glossar-procs.tcl,v
diff -u -N -r1.4 -r1.5
--- openacs-4/packages/glossar/tcl/glossar-procs.tcl	15 Aug 2018 16:37:50 -0000	1.4
+++ openacs-4/packages/glossar/tcl/glossar-procs.tcl	12 Feb 2019 18:00:04 -0000	1.5
@@ -23,7 +23,7 @@
     {-package_id ""}
     {-title ""}
     {-description ""}
-    {-target_category_id [db_null]}
+    {-target_category_id ""}
     {-etat_id ""}
 
 } {
Index: openacs-4/packages/glossar/www/glossar-add.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/glossar/www/glossar-add.tcl,v
diff -u -N -r1.8 -r1.9
--- openacs-4/packages/glossar/www/glossar-add.tcl	15 Aug 2018 16:37:50 -0000	1.8
+++ openacs-4/packages/glossar/www/glossar-add.tcl	12 Feb 2019 18:00:04 -0000	1.9
@@ -63,7 +63,7 @@
     
 	{source_category_id:integer(category) {label "[_ glossar.glossar_single_category]"} {category_tree_id $source_tree_id}  {category_assign_single_p t} {category_require_category_p t}}
 
-	{target_category_id:text(hidden) {value "[db_null]"}}
+	{target_category_id:text(hidden) {value ""}}
 
     }  
 
@@ -108,7 +108,7 @@
 } -new_data {
     
     if {![info exists target_category_id]} {
-	set target_category_id [db_null]
+	set target_category_id ""
     }
     
     glossar::glossary::new -owner_id $owner_id -title "$title" -description "$description" -source_category_id $source_category_id -target_category_id $target_category_id -package_id $package_id -etat_id ""
Index: openacs-4/packages/glossar/www/glossar-edit.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/glossar/www/glossar-edit.tcl,v
diff -u -N -r1.7 -r1.8
--- openacs-4/packages/glossar/www/glossar-edit.tcl	15 Aug 2018 16:37:50 -0000	1.7
+++ openacs-4/packages/glossar/www/glossar-edit.tcl	12 Feb 2019 18:00:04 -0000	1.8
@@ -46,7 +46,7 @@
 
 	{source_category_id:integer(category) {label "[_ glossar.glossar_single_category]"} {category_tree_id $source_tree_id} {category_assign_single_p t} {category_require_category_p t} {category_mapped $source_cat_id}}
 
-	{target_category_id:text(hidden) {value "[db_null]"}}
+	{target_category_id:text(hidden) {value ""}}
     }  
 }
 
Index: openacs-4/packages/image-magick/tcl/image-magick-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/image-magick/tcl/image-magick-procs.tcl,v
diff -u -N -r1.3 -r1.4
--- openacs-4/packages/image-magick/tcl/image-magick-procs.tcl	9 May 2018 15:33:31 -0000	1.3
+++ openacs-4/packages/image-magick/tcl/image-magick-procs.tcl	12 Feb 2019 18:00:04 -0000	1.4
@@ -219,13 +219,6 @@
     if [empty_string_p $user_ip] { set user_ip [ns_conn peeraddr] }
     if [empty_string_p $name] { set name "image-$revision_id" }
 
-    # process empty string => db_null (no need, I think, but correct to do so)
-    foreach var {description parent_id relation_tag} {
-        if [empty_string_p [set $var]] {
-            set $var [db_null]
-        }
-    }
-
     # test file for existence, checking in tmp directory if needed
     if {![file readable $file]} {
         set _file $file
@@ -287,7 +280,6 @@
     if [empty_string_p $user_id] { set user_id [ad_conn user_id] }
     if [empty_string_p $user_ip] { set user_ip [ns_conn peeraddr] }
     if [empty_string_p $name] { set name "image-$revision_id" }
-    if [empty_string_p $description] { set description [db_null] }
 
     # test file for existence, checking in tmp directory if needed
     if {![file readable $file]} {
Index: openacs-4/packages/jabber/www/edit-external-contact-2.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/jabber/www/edit-external-contact-2.tcl,v
diff -u -N -r1.1 -r1.2
--- openacs-4/packages/jabber/www/edit-external-contact-2.tcl	20 Oct 2004 19:36:49 -0000	1.1
+++ openacs-4/packages/jabber/www/edit-external-contact-2.tcl	12 Feb 2019 18:00:04 -0000	1.2
@@ -22,7 +22,7 @@
 
 set user_id [ad_conn user_id]
 set peeraddr [ad_conn peeraddr]
-set db_nulling [db_null]
+set db_nulling ""
 
 if {$friend_first_name != $friend_first_name_old} {
 
Index: openacs-4/packages/jabber/www/edit-user-2.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/jabber/www/edit-user-2.tcl,v
diff -u -N -r1.3 -r1.4
--- openacs-4/packages/jabber/www/edit-user-2.tcl	11 Oct 2018 11:17:07 -0000	1.3
+++ openacs-4/packages/jabber/www/edit-user-2.tcl	12 Feb 2019 18:00:04 -0000	1.4
@@ -13,7 +13,7 @@
 
 
 set user_id [ad_conn user_id]
-set db_nulling [db_null]
+set db_nulling ""
 set peeraddr [ad_conn peeraddr]
 ns_log debug "edit-user-2  1"
 
Index: openacs-4/packages/learning-content/tcl/learning-content-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/learning-content/tcl/learning-content-procs.tcl,v
diff -u -N -r1.4 -r1.5
--- openacs-4/packages/learning-content/tcl/learning-content-procs.tcl	9 May 2018 15:33:31 -0000	1.4
+++ openacs-4/packages/learning-content/tcl/learning-content-procs.tcl	12 Feb 2019 18:00:04 -0000	1.5
@@ -789,7 +789,7 @@
         set user_id [ad_conn user_id]
     }
     set description "New unit for content"
-    set parent_id [db_null]
+    set parent_id ""
     set unit_id [category::add -tree_id $tree_id \
                     -parent_id $parent_id \
                     -locale $language \
Index: openacs-4/packages/press/www/admin/item-create-3.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/press/www/admin/item-create-3.tcl,v
diff -u -N -r1.4 -r1.5
--- openacs-4/packages/press/www/admin/item-create-3.tcl	27 Mar 2018 17:08:50 -0000	1.4
+++ openacs-4/packages/press/www/admin/item-create-3.tcl	12 Feb 2019 18:00:04 -0000	1.5
@@ -12,15 +12,15 @@
     
 } {
     publication_name:notnull
-    {publication_link: "[db_null]"}
+    {publication_link: ""}
     publication_date:notnull
-    {publication_date_desc: "[db_null]"}
+    {publication_date_desc: ""}
     article_title:notnull
-    {article_link:trim "[db_null]"}
+    {article_link:trim ""}
     article_abstract:notnull,allhtml,trim
-    {article_pages:trim "[db_null]"}
-    {release_date:trim  "[db_null]"}
-    {archive_date:trim  "[db_null]"}
+    {article_pages:trim ""}
+    {release_date:trim  ""}
+    {archive_date:trim  ""}
     html_p:notnull
     permanent_p:notnull
     template_id:integer,notnull
@@ -41,7 +41,7 @@
 set press_admin_p [ad_permission_p $package_id press_admin]
 
 if { $press_admin_p == 1 && $permanent_p == "t"} {
-    set archive_date [db_null]
+    set archive_date ""
 } 
 
 # Parent root folder where press_items live
@@ -72,9 +72,9 @@
     set approval_date [dt_sysdate]
     set live_revision_p "t"
 } else {
-    set approval_user [db_null]
-    set approval_ip   [db_null]
-    set approval_date [db_null]
+    set approval_user ""
+    set approval_ip   ""
+    set approval_date ""
     set live_revision_p "f"
 }
 
@@ -90,7 +90,7 @@
 # this will need to be filled in when the news module 
 # extends this press module
 
-set txt [db_null]
+set txt ""
 
 # do insert
 
Index: openacs-4/packages/press/www/admin/one-item-revision-add-3.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/press/www/admin/one-item-revision-add-3.tcl,v
diff -u -N -r1.2 -r1.3
--- openacs-4/packages/press/www/admin/one-item-revision-add-3.tcl	31 Oct 2003 16:09:23 -0000	1.2
+++ openacs-4/packages/press/www/admin/one-item-revision-add-3.tcl	12 Feb 2019 18:00:04 -0000	1.3
@@ -12,12 +12,12 @@
 } { 
     item_id:integer
     publication_name:notnull
-    {publication_link "[db_null]"}
+    {publication_link ""}
     publication_date:notnull
-    {publication_date_desc "[db_null]"}
+    {publication_date_desc ""}
     article_title:notnull
-    {article_link:trim "[db_null]"}
-    {article_pages:trim "[db_null]"}
+    {article_link:trim ""}
+    {article_pages:trim ""}
     article_abstract:notnull,allhtml,trim
     html_p:notnull
     release_date:notnull
@@ -29,7 +29,7 @@
 set package_id [ad_conn package_id]
 
 if {$permanent_p == "t"} {
-    set archive_date [db_null]
+    set archive_date ""
 }
 
 # Get creation info
@@ -46,9 +46,9 @@
     set approval_ip   [ad_conn "peeraddr"]
     set approval_date [dt_sysdate]
 } else {
-    set approval_user [db_null]
-    set approval_ip   [db_null]
-    set approval_date [db_null]
+    set approval_user ""
+    set approval_ip   ""
+    set approval_date ""
 }
 
 # set mime_type
@@ -61,7 +61,7 @@
 
 # reserve empty clob for future
 
-set txt [db_null]
+set txt ""
 
 # make new revision the active revision
 
Index: openacs-4/packages/simple-survey/www/process-response.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/simple-survey/www/process-response.tcl,v
diff -u -N -r1.6 -r1.7
--- openacs-4/packages/simple-survey/www/process-response.tcl	1 Mar 2005 00:01:42 -0000	1.6
+++ openacs-4/packages/simple-survey/www/process-response.tcl	12 Feb 2019 18:00:04 -0000	1.7
@@ -167,17 +167,11 @@
 		    # Deal with multiple responses. 
 		    set checked_responses $response_to_question($question_id)
 		    foreach response_value $checked_responses {
-			if { [empty_string_p $response_value] } {
-			    set response_value [db_null]
-			}
 
 			db_dml survsimp_question_response_checkbox_insert "insert into survsimp_question_responses (response_id, question_id, choice_id)
  values (:response_id, :question_id, :response_value)"
 		    }
 		}  else {
-		    if { [empty_string_p $response_value] } {
-			set response_value [db_null]
-		    }
 
 		    db_dml survsimp_question_response_choice_insert "insert into survsimp_question_responses (response_id, question_id, choice_id)
  values (:response_id, :question_id, :response_value)"
@@ -188,26 +182,17 @@
  values (:response_id, :question_id, :response_value)"
 	    }
 	    "boolean" {
-		if { [empty_string_p $response_value] } {
-		    set response_value [db_null]
-		}
 
 		db_dml survsimp_question_response_boolean_insert "insert into survsimp_question_responses (response_id, question_id, boolean_answer)
  values (:response_id, :question_id, :response_value)"
 	    }
 	    "number" {}
 	    "integer" {
-                if { [empty_string_p $response_value] } {
-                    set response_value [db_null]
-                } 
 
 		db_dml survsimp_question_response_integer_insert "insert into survsimp_question_responses (response_id, question_id, number_answer)
  values (:response_id, :question_id, :response_value)"
 	    }
 	    "text" {
-                if { [empty_string_p $response_value] } {
-                    set response_value [db_null]
-                }
 
 		db_dml survsimp_question_response_text_insert "
 insert into survsimp_question_responses
@@ -216,9 +201,6 @@
  returning clob_answer into :1" -clobs [list $response_value]
 	    }
 	    "date" {
-                if { [empty_string_p $response_value] } {
-                    set response_value [db_null]
-                }
 
 		db_dml survsimp_question_response_date_insert "insert into survsimp_question_responses (response_id, question_id, date_answer)
  values (:response_id, :question_id, :response_value)"
Index: openacs-4/packages/simulation/tcl/template-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/simulation/tcl/template-procs.tcl,v
diff -u -N -r1.75 -r1.76
--- openacs-4/packages/simulation/tcl/template-procs.tcl	9 May 2018 15:33:33 -0000	1.75
+++ openacs-4/packages/simulation/tcl/template-procs.tcl	12 Feb 2019 18:00:04 -0000	1.76
@@ -82,7 +82,7 @@
                     switch $attr {
                         suggested_duration {
                             if { [empty_string_p $row($attr)] } {
-                                set $varname [db_null]
+                                set $varname ""
                             } else {
                                 # TODO B: need better tests for duration before passing it into the database.
                                 set $varname "interval '[db_quote $row($attr)]'"
Index: openacs-4/packages/sloan-bboard/www/message-delete-2.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/sloan-bboard/www/message-delete-2.tcl,v
diff -u -N -r1.3 -r1.4
--- openacs-4/packages/sloan-bboard/www/message-delete-2.tcl	1 Mar 2005 00:01:43 -0000	1.3
+++ openacs-4/packages/sloan-bboard/www/message-delete-2.tcl	12 Feb 2019 18:00:04 -0000	1.4
@@ -38,7 +38,7 @@
 
 if [string eq $replies ""] {
     bboard_message_set_status -message_id $message_id -forum_id $forum_id \
-	    -status [db_null]
+	    -status ""
 } else {
     db_dml bboard_delete_threads {
 	delete from bboard_forum_message_map bfm
Index: openacs-4/packages/survey/www/process-response.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/survey/www/process-response.tcl,v
diff -u -N -r1.17 -r1.18
--- openacs-4/packages/survey/www/process-response.tcl	7 Aug 2017 23:48:29 -0000	1.17
+++ openacs-4/packages/survey/www/process-response.tcl	12 Feb 2019 18:00:04 -0000	1.18
@@ -191,17 +191,11 @@
 			# Deal with multiple responses. 
 			set checked_responses $response_to_question($question_id)
 			foreach response_value $checked_responses {
-			    if { $response_value eq "" } {
-				set response_value [db_null]
-			    }
 
 			    db_dml survey_question_response_checkbox_insert "insert into survey_question_responses (response_id, question_id, choice_id)
  values (:response_id, :question_id, :response_value)"
 			}
 		    }  else {
-			if { $response_value eq "" || [lindex $response_value 0] eq "" } {
-			    set response_value [db_null]
-			}
 
 			db_dml survey_question_response_choice_insert "insert into survey_question_responses (response_id, question_id, choice_id)
  values (:response_id, :question_id, :response_value)"
@@ -212,25 +206,16 @@
  values (:response_id, :question_id, :response_value)"
 		}
 		"boolean" {
-		    if { $response_value eq "" } {
-			set response_value [db_null]
-		    }
 
 		    db_dml survey_question_response_boolean_insert "insert into survey_question_responses (response_id, question_id, boolean_answer)
  values (:response_id, :question_id, :response_value)"
 		}
 		"integer" -
 		"number" {
-		    if { $response_value eq "" } {
-			set response_value [db_null]
-		    } 
 		    db_dml survey_question_response_integer_insert "insert into survey_question_responses (response_id, question_id, number_answer)
  values (:response_id, :question_id, :response_value)"
 		}
 		"text" {
-		    if { $response_value eq "" } {
-			set response_value [db_null]
-		    }
 
 		    db_dml survey_question_response_text_insert "
 insert into survey_question_responses
@@ -239,9 +224,6 @@
 returning clob_answer into :1" -clobs [list $response_value]
 	    }
 	    "date" {
-                if { $response_value eq "" } {
-                    set response_value [db_null]
-                }
 
 		db_dml survey_question_response_date_insert "insert into survey_question_responses (response_id, question_id, date_answer)
 values (:response_id, :question_id, :response_value)"
Index: openacs-4/packages/survey/www/admin/process-response.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/survey/www/admin/process-response.tcl,v
diff -u -N -r1.7 -r1.8
--- openacs-4/packages/survey/www/admin/process-response.tcl	7 Aug 2017 23:48:29 -0000	1.7
+++ openacs-4/packages/survey/www/admin/process-response.tcl	12 Feb 2019 18:00:04 -0000	1.8
@@ -216,17 +216,11 @@
 			# Deal with multiple responses. 
 			set checked_responses $response_to_question($question_id)
 			foreach response_value $checked_responses {
-			    if { $response_value eq "" } {
-				set response_value [db_null]
-			    }
 
 			    db_dml survey_question_response_checkbox_insert "insert into survey_question_responses (response_id, question_id, choice_id)
  values (:response_id, :question_id, :response_value)"
 			}
 		    }  else {
-			if { $response_value eq "" || [lindex $response_value 0] eq "" } {
-			    set response_value [db_null]
-			}
 
 			db_dml survey_question_response_choice_insert "insert into survey_question_responses (response_id, question_id, choice_id)
  values (:response_id, :question_id, :response_value)"
@@ -237,25 +231,16 @@
  values (:response_id, :question_id, :response_value)"
 		}
 		"boolean" {
-		    if { $response_value eq "" } {
-			set response_value [db_null]
-		    }
 
 		    db_dml survey_question_response_boolean_insert "insert into survey_question_responses (response_id, question_id, boolean_answer)
  values (:response_id, :question_id, :response_value)"
 		}
 		"integer" -
 		"number" {
-		    if { $response_value eq "" } {
-			set response_value [db_null]
-		    } 
 		    db_dml survey_question_response_integer_insert "insert into survey_question_responses (response_id, question_id, number_answer)
  values (:response_id, :question_id, :response_value)"
 		}
 		"text" {
-		    if { $response_value eq "" } {
-			set response_value [db_null]
-		    }
 
 		    db_dml survey_question_response_text_insert "
 insert into survey_question_responses
@@ -264,9 +249,6 @@
 returning clob_answer into :1" -clobs [list $response_value]
 	    }
 	    "date" {
-                if { $response_value eq "" } {
-                    set response_value [db_null]
-                }
 
 		db_dml survey_question_response_date_insert "insert into survey_question_responses (response_id, question_id, date_answer)
 values (:response_id, :question_id, :response_value)"
Index: openacs-4/packages/workflow/tcl/action-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/workflow/tcl/action-procs.tcl,v
diff -u -N -r1.40 -r1.41
--- openacs-4/packages/workflow/tcl/action-procs.tcl	9 May 2018 15:33:33 -0000	1.40
+++ openacs-4/packages/workflow/tcl/action-procs.tcl	12 Feb 2019 18:00:04 -0000	1.41
@@ -250,8 +250,6 @@
                     set row(parent_action_id) [workflow::action::get_id \
                                                     -workflow_id $workflow_id \
                                                     -short_name $row(parent_action)]
-                } else {
-                    set row(parent_action_id) [db_null]
                 }
                 unset row(parent_action)
                 unset missing_elm(parent_action)
@@ -311,7 +309,7 @@
                         }
                         assigned_role {
                             if { $row($attr) eq "" } {
-                                set $varname [db_null]
+                                set $varname ""
                             } else {
                                 # Get role_id by short_name
                                 set $varname [workflow::role::get_id \
@@ -994,8 +992,6 @@
                     set row(new_state_id) [workflow::state::fsm::get_id \
                                                -workflow_id $workflow_id \
                                                -short_name $row(new_state)]
-                } else {
-                    set row(new_state_id) [db_null]
                 }
                 unset row(new_state)
             }
Index: openacs-4/packages/workflow/tcl/state-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/workflow/tcl/state-procs.tcl,v
diff -u -N -r1.22 -r1.23
--- openacs-4/packages/workflow/tcl/state-procs.tcl	9 May 2018 15:33:33 -0000	1.22
+++ openacs-4/packages/workflow/tcl/state-procs.tcl	12 Feb 2019 18:00:04 -0000	1.23
@@ -170,8 +170,6 @@
                     set row(parent_action_id) [workflow::action::get_id \
                                                     -workflow_id $workflow_id \
                                                     -short_name $row(parent_action)]
-                } else {
-                    set row(parent_action_id) [db_null]
                 }
                 unset row(parent_action)
                 unset missing_elm(parent_action)
Index: openacs-4/packages/workflow/tcl/workflow-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/workflow/tcl/workflow-procs.tcl,v
diff -u -N -r1.34 -r1.35
--- openacs-4/packages/workflow/tcl/workflow-procs.tcl	9 May 2018 15:33:33 -0000	1.34
+++ openacs-4/packages/workflow/tcl/workflow-procs.tcl	12 Feb 2019 18:00:04 -0000	1.35
@@ -149,14 +149,14 @@
                 if { [ad_conn isconnected] } {
                     set row(creation_user) [ad_conn user_id]
                 } else {
-                    set row(creation_user) [db_null]
+                    set row(creation_user) ""
                 }
             }
             if { ![info exists row(creation_ip)] } {
                 if { [ad_conn isconnected] } {
                     set row(creation_ip) [ad_conn peeraddr]
                 } else {
-                    set row(creation_ip) [db_null]
+                    set row(creation_ip) ""
                 }
             }
             # Default object_type