move plpgsql

src/pl/plpgsql/test/README

+Test suite for PL/pgSQL
+
+Scenario:
+
+    A building with a modern TP cabel installation where any
+    of the wall connectors can be used to plug in phones,
+    ethernet interfaces or local office hubs. The backside
+    of the wall connectors is wired to one of several patch-
+    fields in the building.
+
+    In the patchfields, there are hubs and all the slots
+    representing the wall connectors. In addition there are
+    slots that can represent a phone line from the central
+    phone system.
+
+    Triggers ensure consistency of the patching information.
+
+    Functions are used to build up powerful views that let
+    you look behind the wall when looking at a patchfield
+    or into a room.
+
+

src/pl/plpgsql/test/mklang.sql

+--
+-- PL/pgSQL language declaration
+--
+-- $Header: /cvsroot/pgsql/src/pl/plpgsql/test/Attic/mklang.sql,v 1.1 1998/08/24 19:16:27 momjian Exp $
+--
+
+create function plpgsql_call_handler() returns opaque
+	as '/usr/local/pgsql/lib/plpgsql.so'
+	language 'C';
+
+create trusted procedural language 'plpgsql'
+	handler plpgsql_call_handler
+	lancompiler 'PL/pgSQL';
+

src/pl/plpgsql/test/runtest

+#!/bin/sh
+
+DB=plpgsql_test
+export DB
+
+FRONTEND="psql -n -e -q"
+export FRONTEND
+
+echo "*** destroy old $DB database ***"
+destroydb $DB
+
+echo "*** create new $DB database ***"
+createdb $DB
+
+echo "*** install PL/pgSQL ***"
+$FRONTEND -f mklang.sql -d $DB >/dev/null 2>&1
+
+echo "*** create tables ***"
+$FRONTEND -f tables.sql -d $DB >output/tables.out 2>&1
+if cmp -s output/tables.out expected/tables.out ; then
+    echo "OK"
+else
+    echo "FAILED"
+fi
+
+echo "*** create triggers ***"
+$FRONTEND -f triggers.sql -d $DB >output/triggers.out 2>&1
+if cmp -s output/triggers.out expected/triggers.out ; then
+    echo "OK"
+else
+    echo "FAILED"
+fi
+
+echo "*** create views and support functions ***"
+$FRONTEND -f views.sql -d $DB >output/views.out 2>&1
+if cmp -s output/views.out expected/views.out ; then
+    echo "OK"
+else
+    echo "FAILED"
+fi
+
+echo "*** running tests ***"
+$FRONTEND -f test.sql -d $DB >output/test.out 2>&1
+if cmp -s output/test.out expected/test.out ; then
+    echo "OK"
+else
+    echo "FAILED"
+fi
+

src/pl/plpgsql/test/tables.sql

+-- ************************************************************
+-- * 
+-- * Tables for the patchfield test of PL/pgSQL
+-- * 
+-- * $Header: /cvsroot/pgsql/src/pl/plpgsql/test/Attic/tables.sql,v 1.1 1998/08/24 19:16:27 momjian Exp $
+-- * 
+-- ************************************************************
+
+create table Room (
+    roomno	char(8),
+    comment	text
+);
+
+create unique index Room_rno on Room using btree (roomno bpchar_ops);
+
+
+create table WSlot (
+    slotname	char(20),
+    roomno	char(8),
+    slotlink	char(20),
+    backlink	char(20)
+);
+
+create unique index WSlot_name on WSlot using btree (slotname bpchar_ops);
+
+
+create table PField (
+    name	text,
+    comment	text
+);
+
+create unique index PField_name on PField using btree (name text_ops);
+
+
+create table PSlot (
+    slotname	char(20),
+    pfname	text,
+    slotlink	char(20),
+    backlink	char(20)
+);
+
+create unique index PSlot_name on PSlot using btree (slotname bpchar_ops);
+
+
+create table PLine (
+    slotname	char(20),
+    phonenumber	char(20),
+    comment	text,
+    backlink	char(20)
+);
+
+create unique index PLine_name on PLine using btree (slotname bpchar_ops);
+
+
+create table Hub (
+    name	char(14),
+    comment	text,
+    nslots	integer
+);
+
+create unique index Hub_name on Hub using btree (name bpchar_ops);
+
+
+create table HSlot (
+    slotname	char(20),
+    hubname	char(14),
+    slotno	integer,
+    slotlink	char(20)
+);
+
+create unique index HSlot_name on HSlot using btree (slotname bpchar_ops);
+create index HSlot_hubname on HSlot using btree (hubname bpchar_ops);
+
+
+create table System (
+    name	text,
+    comment	text
+);
+
+create unique index System_name on System using btree (name text_ops);
+
+
+create table IFace (
+    slotname	char(20),
+    sysname	text,
+    ifname	text,
+    slotlink	char(20)
+);
+
+create unique index IFace_name on IFace using btree (slotname bpchar_ops);
+
+
+create table PHone (
+    slotname	char(20),
+    comment	text,
+    slotlink	char(20)
+);
+
+create unique index PHone_name on PHone using btree (slotname bpchar_ops);
+
+

src/pl/plpgsql/test/test.sql

+--
+-- First we build the house - so we create the rooms
+--
+insert into Room values ('001', 'Entrance');
+insert into Room values ('002', 'Office');
+insert into Room values ('003', 'Office');
+insert into Room values ('004', 'Technical');
+insert into Room values ('101', 'Office');
+insert into Room values ('102', 'Conference');
+insert into Room values ('103', 'Restroom');
+insert into Room values ('104', 'Technical');
+insert into Room values ('105', 'Office');
+insert into Room values ('106', 'Office');
+
+--
+-- Second we install the wall connectors
+--
+insert into WSlot values ('WS.001.1a', '001', '', '');
+insert into WSlot values ('WS.001.1b', '001', '', '');
+insert into WSlot values ('WS.001.2a', '001', '', '');
+insert into WSlot values ('WS.001.2b', '001', '', '');
+insert into WSlot values ('WS.001.3a', '001', '', '');
+insert into WSlot values ('WS.001.3b', '001', '', '');
+
+insert into WSlot values ('WS.002.1a', '002', '', '');
+insert into WSlot values ('WS.002.1b', '002', '', '');
+insert into WSlot values ('WS.002.2a', '002', '', '');
+insert into WSlot values ('WS.002.2b', '002', '', '');
+insert into WSlot values ('WS.002.3a', '002', '', '');
+insert into WSlot values ('WS.002.3b', '002', '', '');
+
+insert into WSlot values ('WS.003.1a', '003', '', '');
+insert into WSlot values ('WS.003.1b', '003', '', '');
+insert into WSlot values ('WS.003.2a', '003', '', '');
+insert into WSlot values ('WS.003.2b', '003', '', '');
+insert into WSlot values ('WS.003.3a', '003', '', '');
+insert into WSlot values ('WS.003.3b', '003', '', '');
+
+insert into WSlot values ('WS.101.1a', '101', '', '');
+insert into WSlot values ('WS.101.1b', '101', '', '');
+insert into WSlot values ('WS.101.2a', '101', '', '');
+insert into WSlot values ('WS.101.2b', '101', '', '');
+insert into WSlot values ('WS.101.3a', '101', '', '');
+insert into WSlot values ('WS.101.3b', '101', '', '');
+
+insert into WSlot values ('WS.102.1a', '102', '', '');
+insert into WSlot values ('WS.102.1b', '102', '', '');
+insert into WSlot values ('WS.102.2a', '102', '', '');
+insert into WSlot values ('WS.102.2b', '102', '', '');
+insert into WSlot values ('WS.102.3a', '102', '', '');
+insert into WSlot values ('WS.102.3b', '102', '', '');
+
+insert into WSlot values ('WS.105.1a', '105', '', '');
+insert into WSlot values ('WS.105.1b', '105', '', '');
+insert into WSlot values ('WS.105.2a', '105', '', '');
+insert into WSlot values ('WS.105.2b', '105', '', '');
+insert into WSlot values ('WS.105.3a', '105', '', '');
+insert into WSlot values ('WS.105.3b', '105', '', '');
+
+insert into WSlot values ('WS.106.1a', '106', '', '');
+insert into WSlot values ('WS.106.1b', '106', '', '');
+insert into WSlot values ('WS.106.2a', '106', '', '');
+insert into WSlot values ('WS.106.2b', '106', '', '');
+insert into WSlot values ('WS.106.3a', '106', '', '');
+insert into WSlot values ('WS.106.3b', '106', '', '');
+
+--
+-- Now create the patch fields and their slots
+--
+insert into PField values ('PF0_1', 'Wallslots basement');
+
+--
+-- The cables for these will be made later, so they are unconnected for now
+--
+insert into PSlot values ('PS.base.a1', 'PF0_1', '', '');
+insert into PSlot values ('PS.base.a2', 'PF0_1', '', '');
+insert into PSlot values ('PS.base.a3', 'PF0_1', '', '');
+insert into PSlot values ('PS.base.a4', 'PF0_1', '', '');
+insert into PSlot values ('PS.base.a5', 'PF0_1', '', '');
+insert into PSlot values ('PS.base.a6', 'PF0_1', '', '');
+
+--
+-- These are already wired to the wall connectors
+--
+insert into PSlot values ('PS.base.b1', 'PF0_1', '', 'WS.002.1a');
+insert into PSlot values ('PS.base.b2', 'PF0_1', '', 'WS.002.1b');
+insert into PSlot values ('PS.base.b3', 'PF0_1', '', 'WS.002.2a');
+insert into PSlot values ('PS.base.b4', 'PF0_1', '', 'WS.002.2b');
+insert into PSlot values ('PS.base.b5', 'PF0_1', '', 'WS.002.3a');
+insert into PSlot values ('PS.base.b6', 'PF0_1', '', 'WS.002.3b');
+
+insert into PSlot values ('PS.base.c1', 'PF0_1', '', 'WS.003.1a');
+insert into PSlot values ('PS.base.c2', 'PF0_1', '', 'WS.003.1b');
+insert into PSlot values ('PS.base.c3', 'PF0_1', '', 'WS.003.2a');
+insert into PSlot values ('PS.base.c4', 'PF0_1', '', 'WS.003.2b');
+insert into PSlot values ('PS.base.c5', 'PF0_1', '', 'WS.003.3a');
+insert into PSlot values ('PS.base.c6', 'PF0_1', '', 'WS.003.3b');
+
+--
+-- This patchfield will be renamed later into PF0_2 - so its
+-- slots references in pfname should follow
+--
+insert into PField values ('PF0_X', 'Phonelines basement');
+
+insert into PSlot values ('PS.base.ta1', 'PF0_X', '', '');
+insert into PSlot values ('PS.base.ta2', 'PF0_X', '', '');
+insert into PSlot values ('PS.base.ta3', 'PF0_X', '', '');
+insert into PSlot values ('PS.base.ta4', 'PF0_X', '', '');
+insert into PSlot values ('PS.base.ta5', 'PF0_X', '', '');
+insert into PSlot values ('PS.base.ta6', 'PF0_X', '', '');
+
+insert into PSlot values ('PS.base.tb1', 'PF0_X', '', '');
+insert into PSlot values ('PS.base.tb2', 'PF0_X', '', '');
+insert into PSlot values ('PS.base.tb3', 'PF0_X', '', '');
+insert into PSlot values ('PS.base.tb4', 'PF0_X', '', '');
+insert into PSlot values ('PS.base.tb5', 'PF0_X', '', '');
+insert into PSlot values ('PS.base.tb6', 'PF0_X', '', '');
+
+insert into PField values ('PF1_1', 'Wallslots 1st floor');
+
+insert into PSlot values ('PS.1st.a1', 'PF1_1', '', 'WS.101.1a');
+insert into PSlot values ('PS.1st.a2', 'PF1_1', '', 'WS.101.1b');
+insert into PSlot values ('PS.1st.a3', 'PF1_1', '', 'WS.101.2a');
+insert into PSlot values ('PS.1st.a4', 'PF1_1', '', 'WS.101.2b');
+insert into PSlot values ('PS.1st.a5', 'PF1_1', '', 'WS.101.3a');
+insert into PSlot values ('PS.1st.a6', 'PF1_1', '', 'WS.101.3b');
+
+insert into PSlot values ('PS.1st.b1', 'PF1_1', '', 'WS.102.1a');
+insert into PSlot values ('PS.1st.b2', 'PF1_1', '', 'WS.102.1b');
+insert into PSlot values ('PS.1st.b3', 'PF1_1', '', 'WS.102.2a');
+insert into PSlot values ('PS.1st.b4', 'PF1_1', '', 'WS.102.2b');
+insert into PSlot values ('PS.1st.b5', 'PF1_1', '', 'WS.102.3a');
+insert into PSlot values ('PS.1st.b6', 'PF1_1', '', 'WS.102.3b');
+
+insert into PSlot values ('PS.1st.c1', 'PF1_1', '', 'WS.105.1a');
+insert into PSlot values ('PS.1st.c2', 'PF1_1', '', 'WS.105.1b');
+insert into PSlot values ('PS.1st.c3', 'PF1_1', '', 'WS.105.2a');
+insert into PSlot values ('PS.1st.c4', 'PF1_1', '', 'WS.105.2b');
+insert into PSlot values ('PS.1st.c5', 'PF1_1', '', 'WS.105.3a');
+insert into PSlot values ('PS.1st.c6', 'PF1_1', '', 'WS.105.3b');
+
+insert into PSlot values ('PS.1st.d1', 'PF1_1', '', 'WS.106.1a');
+insert into PSlot values ('PS.1st.d2', 'PF1_1', '', 'WS.106.1b');
+insert into PSlot values ('PS.1st.d3', 'PF1_1', '', 'WS.106.2a');
+insert into PSlot values ('PS.1st.d4', 'PF1_1', '', 'WS.106.2b');
+insert into PSlot values ('PS.1st.d5', 'PF1_1', '', 'WS.106.3a');
+insert into PSlot values ('PS.1st.d6', 'PF1_1', '', 'WS.106.3b');
+
+--
+-- Now we wire the wall connectors 1a-2a in room 001 to the
+-- patchfield. In the second update we make an error, and
+-- correct it after
+--
+update PSlot set backlink = 'WS.001.1a' where slotname = 'PS.base.a1';
+update PSlot set backlink = 'WS.001.1b' where slotname = 'PS.base.a3';
+select * from WSlot where roomno = '001' order by slotname;
+select * from PSlot where slotname ~ 'PS.base.a' order by slotname;
+update PSlot set backlink = 'WS.001.2a' where slotname = 'PS.base.a3';
+select * from WSlot where roomno = '001' order by slotname;
+select * from PSlot where slotname ~ 'PS.base.a' order by slotname;
+update PSlot set backlink = 'WS.001.1b' where slotname = 'PS.base.a2';
+select * from WSlot where roomno = '001' order by slotname;
+select * from PSlot where slotname ~ 'PS.base.a' order by slotname;
+
+--
+-- Same procedure for 2b-3b but this time updating the WSlot instead
+-- of the PSlot. Due to the triggers the result is the same:
+-- WSlot and corresponding PSlot point to each other.
+--
+update WSlot set backlink = 'PS.base.a4' where slotname = 'WS.001.2b';
+update WSlot set backlink = 'PS.base.a6' where slotname = 'WS.001.3a';
+select * from WSlot where roomno = '001' order by slotname;
+select * from PSlot where slotname ~ 'PS.base.a' order by slotname;
+update WSlot set backlink = 'PS.base.a6' where slotname = 'WS.001.3b';
+select * from WSlot where roomno = '001' order by slotname;
+select * from PSlot where slotname ~ 'PS.base.a' order by slotname;
+update WSlot set backlink = 'PS.base.a5' where slotname = 'WS.001.3a';
+select * from WSlot where roomno = '001' order by slotname;
+select * from PSlot where slotname ~ 'PS.base.a' order by slotname;
+
+insert into PField values ('PF1_2', 'Phonelines 1st floor');
+
+insert into PSlot values ('PS.1st.ta1', 'PF1_2', '', '');
+insert into PSlot values ('PS.1st.ta2', 'PF1_2', '', '');
+insert into PSlot values ('PS.1st.ta3', 'PF1_2', '', '');
+insert into PSlot values ('PS.1st.ta4', 'PF1_2', '', '');
+insert into PSlot values ('PS.1st.ta5', 'PF1_2', '', '');
+insert into PSlot values ('PS.1st.ta6', 'PF1_2', '', '');
+
+insert into PSlot values ('PS.1st.tb1', 'PF1_2', '', '');
+insert into PSlot values ('PS.1st.tb2', 'PF1_2', '', '');
+insert into PSlot values ('PS.1st.tb3', 'PF1_2', '', '');
+insert into PSlot values ('PS.1st.tb4', 'PF1_2', '', '');
+insert into PSlot values ('PS.1st.tb5', 'PF1_2', '', '');
+insert into PSlot values ('PS.1st.tb6', 'PF1_2', '', '');
+
+--
+-- Fix the wrong name for patchfield PF0_2
+--
+update PField set name = 'PF0_2' where name = 'PF0_X';
+
+select * from PSlot order by slotname;
+select * from WSlot order by slotname;
+
+--
+-- Install the central phone system and create the phone numbers.
+-- They are weired on insert to the patchfields. Again the
+-- triggers automatically tell the PSlots to update their
+-- backlink field.
+--
+insert into PLine values ('PL.001', '-0', 'Central call', 'PS.base.ta1');
+insert into PLine values ('PL.002', '-101', '', 'PS.base.ta2');
+insert into PLine values ('PL.003', '-102', '', 'PS.base.ta3');
+insert into PLine values ('PL.004', '-103', '', 'PS.base.ta5');
+insert into PLine values ('PL.005', '-104', '', 'PS.base.ta6');
+insert into PLine values ('PL.006', '-106', '', 'PS.base.tb2');
+insert into PLine values ('PL.007', '-108', '', 'PS.base.tb3');
+insert into PLine values ('PL.008', '-109', '', 'PS.base.tb4');
+insert into PLine values ('PL.009', '-121', '', 'PS.base.tb5');
+insert into PLine values ('PL.010', '-122', '', 'PS.base.tb6');
+insert into PLine values ('PL.015', '-134', '', 'PS.1st.ta1');
+insert into PLine values ('PL.016', '-137', '', 'PS.1st.ta3');
+insert into PLine values ('PL.017', '-139', '', 'PS.1st.ta4');
+insert into PLine values ('PL.018', '-362', '', 'PS.1st.tb1');
+insert into PLine values ('PL.019', '-363', '', 'PS.1st.tb2');
+insert into PLine values ('PL.020', '-364', '', 'PS.1st.tb3');
+insert into PLine values ('PL.021', '-365', '', 'PS.1st.tb5');
+insert into PLine values ('PL.022', '-367', '', 'PS.1st.tb6');
+insert into PLine values ('PL.028', '-501', 'Fax entrance', 'PS.base.ta2');
+insert into PLine values ('PL.029', '-502', 'Fax 1st floor', 'PS.1st.ta1');
+
+--
+-- Buy some phones, plug them into the wall and patch the
+-- phone lines to the corresponding patchfield slots.
+--
+insert into PHone values ('PH.hc001', 'Hicom standard', 'WS.001.1a');
+update PSlot set slotlink = 'PS.base.ta1' where slotname = 'PS.base.a1';
+insert into PHone values ('PH.hc002', 'Hicom standard', 'WS.002.1a');
+update PSlot set slotlink = 'PS.base.ta5' where slotname = 'PS.base.b1';
+insert into PHone values ('PH.hc003', 'Hicom standard', 'WS.002.2a');
+update PSlot set slotlink = 'PS.base.tb2' where slotname = 'PS.base.b3';
+insert into PHone values ('PH.fax001', 'Canon fax', 'WS.001.2a');
+update PSlot set slotlink = 'PS.base.ta2' where slotname = 'PS.base.a3';
+
+--
+-- Install a hub at one of the patchfields, plug a computers
+-- ethernet interface into the wall and patch it to the hub.
+--
+insert into Hub values ('base.hub1', 'Patchfield PF0_1 hub', 16);
+insert into System values ('orion', 'PC');
+insert into IFace values ('IF', 'orion', 'eth0', 'WS.002.1b');
+update PSlot set slotlink = 'HS.base.hub1.1' where slotname = 'PS.base.b2';
+
+--
+-- Now we take a look at the patchfield
+--
+select * from PField_v1 where pfname = 'PF0_1' order by slotname;
+select * from PField_v1 where pfname = 'PF0_2' order by slotname;
+
+--
+-- Finally we want errors
+--
+insert into PField values ('PF1_1', 'should fail due to unique index');
+update PSlot set backlink = 'WS.not.there' where slotname = 'PS.base.a1';
+update PSlot set backlink = 'XX.illegal' where slotname = 'PS.base.a1';
+update PSlot set slotlink = 'PS.not.there' where slotname = 'PS.base.a1';
+update PSlot set slotlink = 'XX.illegal' where slotname = 'PS.base.a1';
+insert into HSlot values ('HS', 'base.hub1', 1, '');
+insert into HSlot values ('HS', 'base.hub1', 20, '');
+delete from HSlot;
+insert into IFace values ('IF', 'notthere', 'eth0', '');
+insert into IFace values ('IF', 'orion', 'ethernet_interface_name_too_long', '');

src/pl/plpgsql/test/triggers.sql

+-- ************************************************************
+-- * 
+-- * Trigger procedures and functions for the patchfield
+-- * test of PL/pgSQL
+-- * 
+-- * $Header: /cvsroot/pgsql/src/pl/plpgsql/test/Attic/triggers.sql,v 1.1 1998/08/24 19:16:27 momjian Exp $
+-- * 
+-- ************************************************************
+
+
+-- ************************************************************
+-- * AFTER UPDATE on Room
+-- *	- If room no changes let wall slots follow
+-- ************************************************************
+create function tg_room_au() returns opaque as '
+begin
+    if new.roomno != old.roomno then
+        update WSlot set roomno = new.roomno where roomno = old.roomno;
+    end if;
+    return new;
+end;
+' language 'plpgsql';
+
+create trigger tg_room_au after update
+    on Room for each row execute procedure tg_room_au();
+
+
+-- ************************************************************
+-- * AFTER DELETE on Room
+-- *	- delete wall slots in this room
+-- ************************************************************
+create function tg_room_ad() returns opaque as '
+begin
+    delete from WSlot where roomno = old.roomno;
+    return old;
+end;
+' language 'plpgsql';
+
+create trigger tg_room_ad after delete
+    on Room for each row execute procedure tg_room_ad();
+
+
+-- ************************************************************
+-- * BEFORE INSERT or UPDATE on WSlot
+-- *	- Check that room exists
+-- ************************************************************
+create function tg_wslot_biu() returns opaque as '
+begin
+    if count(*) = 0 from Room where roomno = new.roomno then
+        raise exception ''Room % does not exist'', new.roomno;
+    end if;
+    return new;
+end;
+' language 'plpgsql';
+
+create trigger tg_wslot_biu before insert or update
+    on WSlot for each row execute procedure tg_wslot_biu();
+
+
+-- ************************************************************
+-- * AFTER UPDATE on PField
+-- *	- Let PSlots of this field follow
+-- ************************************************************
+create function tg_pfield_au() returns opaque as '
+begin
+    if new.name != old.name then
+        update PSlot set pfname = new.name where pfname = old.name;
+    end if;
+    return new;
+end;
+' language 'plpgsql';
+
+create trigger tg_pfield_au after update
+    on PField for each row execute procedure tg_pfield_au();
+
+
+-- ************************************************************
+-- * AFTER DELETE on PField
+-- *	- Remove all slots of this patchfield
+-- ************************************************************
+create function tg_pfield_ad() returns opaque as '
+begin
+    delete from PSlot where pfname = old.name;
+    return old;
+end;
+' language 'plpgsql';
+
+create trigger tg_pfield_ad after delete
+    on PField for each row execute procedure tg_pfield_ad();
+
+
+-- ************************************************************
+-- * BEFORE INSERT or UPDATE on PSlot
+-- *	- Ensure that our patchfield does exist
+-- ************************************************************
+create function tg_pslot_biu() returns opaque as '
+declare
+    pfrec	record;
+    rename new to ps;
+begin
+    select into pfrec * from PField where name = ps.pfname;
+    if not found then
+        raise exception ''Patchfield "%" does not exist'', ps.pfname;
+    end if;
+    return ps;
+end;
+' language 'plpgsql';
+
+create trigger tg_pslot_biu before insert or update
+    on PSlot for each row execute procedure tg_pslot_biu();
+
+
+-- ************************************************************
+-- * AFTER UPDATE on System
+-- *	- If system name changes let interfaces follow
+-- ************************************************************
+create function tg_system_au() returns opaque as '
+begin
+    if new.name != old.name then
+        update IFace set sysname = new.name where sysname = old.name;
+    end if;
+    return new;
+end;
+' language 'plpgsql';
+
+create trigger tg_system_au after update
+    on System for each row execute procedure tg_system_au();
+
+
+-- ************************************************************
+-- * BEFORE INSERT or UPDATE on IFace
+-- *	- set the slotname to IF.sysname.ifname
+-- ************************************************************
+create function tg_iface_biu() returns opaque as '
+declare
+    sname	text;
+    sysrec	record;
+begin
+    select into sysrec * from system where name = new.sysname;
+    if not found then
+        raise exception ''system "%" does not exist'', new.sysname;
+    end if;
+    sname := ''IF.'' || new.sysname;
+    sname := sname || ''.'';
+    sname := sname || new.ifname;
+    if length(sname) > 20 then
+        raise exception ''IFace slotname "%" too long (20 char max)'', sname;
+    end if;
+    new.slotname := sname;
+    return new;
+end;
+' language 'plpgsql';
+
+create trigger tg_iface_biu before insert or update
+    on IFace for each row execute procedure tg_iface_biu();
+
+
+-- ************************************************************
+-- * AFTER INSERT or UPDATE or DELETE on Hub
+-- *	- insert/delete/rename slots as required
+-- ************************************************************
+create function tg_hub_a() returns opaque as '
+declare
+    hname	text;
+    dummy	integer;
+begin
+    if tg_op = ''INSERT'' then
+	dummy := tg_hub_adjustslots(new.name, 0, new.nslots);
+	return new;
+    end if;
+    if tg_op = ''UPDATE'' then
+	if new.name != old.name then
+	    update HSlot set hubname = new.name where hubname = old.name;
+	end if;
+	dummy := tg_hub_adjustslots(new.name, old.nslots, new.nslots);
+	return new;
+    end if;
+    if tg_op = ''DELETE'' then
+	dummy := tg_hub_adjustslots(old.name, old.nslots, 0);
+	return old;
+    end if;
+end;
+' language 'plpgsql';
+
+create trigger tg_hub_a after insert or update or delete
+    on Hub for each row execute procedure tg_hub_a();
+
+
+-- ************************************************************
+-- * Support function to add/remove slots of Hub
+-- ************************************************************
+create function tg_hub_adjustslots(bpchar, integer, integer)
+returns integer as '
+declare
+    hname	alias for $1;
+    oldnslots	alias for $2;
+    newnslots	alias for $3;
+begin
+    if newnslots = oldnslots then
+        return 0;
+    end if;
+    if newnslots < oldnslots then
+        delete from HSlot where hubname = hname and slotno > newnslots;
+	return 0;
+    end if;
+    for i in oldnslots + 1 .. newnslots loop
+        insert into HSlot (slotname, hubname, slotno, slotlink)
+		values (''HS.dummy'', hname, i, '''');
+    end loop;
+    return 0;
+end;
+' language 'plpgsql';
+
+
+-- ************************************************************
+-- * BEFORE INSERT or UPDATE on HSlot
+-- *	- prevent from manual manipulation
+-- *	- set the slotname to HS.hubname.slotno
+-- ************************************************************
+create function tg_hslot_biu() returns opaque as '
+declare
+    sname	text;
+    xname	HSlot.slotname%TYPE;
+    hubrec	record;
+begin
+    select into hubrec * from Hub where name = new.hubname;
+    if not found then
+        raise exception ''no manual manipulation of HSlot'';
+    end if;
+    if new.slotno < 1 or new.slotno > hubrec.nslots then
+        raise exception ''no manual manipulation of HSlot'';
+    end if;
+    if tg_op = ''UPDATE'' then
+	if new.hubname != old.hubname then
+	    if count(*) > 0 from Hub where name = old.hubname then
+		raise exception ''no manual manipulation of HSlot'';
+	    end if;
+	end if;
+    end if;
+    sname := ''HS.'' || trim(new.hubname);
+    sname := sname || ''.'';
+    sname := sname || new.slotno::text;
+    if length(sname) > 20 then
+        raise exception ''HSlot slotname "%" too long (20 char max)'', sname;
+    end if;
+    new.slotname := sname;
+    return new;
+end;
+' language 'plpgsql';
+
+create trigger tg_hslot_biu before insert or update
+    on HSlot for each row execute procedure tg_hslot_biu();
+
+
+-- ************************************************************
+-- * BEFORE DELETE on HSlot
+-- *	- prevent from manual manipulation
+-- ************************************************************
+create function tg_hslot_bd() returns opaque as '
+declare
+    hubrec	record;
+begin
+    select into hubrec * from Hub where name = old.hubname;
+    if not found then
+        return old;
+    end if;
+    if old.slotno > hubrec.nslots then
+        return old;
+    end if;
+    raise exception ''no manual manipulation of HSlot'';
+end;
+' language 'plpgsql';
+
+create trigger tg_hslot_bd before delete
+    on HSlot for each row execute procedure tg_hslot_bd();
+
+
+-- ************************************************************
+-- * BEFORE INSERT on all slots
+-- *	- Check name prefix
+-- ************************************************************
+create function tg_chkslotname() returns opaque as '
+begin
+    if substr(new.slotname, 1, 2) != tg_argv[0] then
+        raise exception ''slotname must begin with %'', tg_argv[0];
+    end if;
+    return new;
+end;
+' language 'plpgsql';
+
+create trigger tg_chkslotname before insert
+    on PSlot for each row execute procedure tg_chkslotname('PS');
+
+create trigger tg_chkslotname before insert
+    on WSlot for each row execute procedure tg_chkslotname('WS');
+
+create trigger tg_chkslotname before insert
+    on PLine for each row execute procedure tg_chkslotname('PL');
+
+create trigger tg_chkslotname before insert
+    on IFace for each row execute procedure tg_chkslotname('IF');
+
+create trigger tg_chkslotname before insert
+    on PHone for each row execute procedure tg_chkslotname('PH');
+
+
+-- ************************************************************
+-- * BEFORE INSERT or UPDATE on all slots with slotlink
+-- *	- Set slotlink to empty string if NULL value given
+-- ************************************************************
+create function tg_chkslotlink() returns opaque as '
+begin
+    if new.slotlink isnull then
+        new.slotlink := '''';
+    end if;
+    return new;
+end;
+' language 'plpgsql';
+
+create trigger tg_chkslotlink before insert or update
+    on PSlot for each row execute procedure tg_chkslotlink();
+
+create trigger tg_chkslotlink before insert or update
+    on WSlot for each row execute procedure tg_chkslotlink();
+
+create trigger tg_chkslotlink before insert or update
+    on IFace for each row execute procedure tg_chkslotlink();
+
+create trigger tg_chkslotlink before insert or update
+    on HSlot for each row execute procedure tg_chkslotlink();
+
+create trigger tg_chkslotlink before insert or update
+    on PHone for each row execute procedure tg_chkslotlink();
+
+
+-- ************************************************************
+-- * BEFORE INSERT or UPDATE on all slots with backlink
+-- *	- Set backlink to empty string if NULL value given
+-- ************************************************************
+create function tg_chkbacklink() returns opaque as '
+begin
+    if new.backlink isnull then
+        new.backlink := '''';
+    end if;
+    return new;
+end;
+' language 'plpgsql';
+
+create trigger tg_chkbacklink before insert or update
+    on PSlot for each row execute procedure tg_chkbacklink();
+
+create trigger tg_chkbacklink before insert or update
+    on WSlot for each row execute procedure tg_chkbacklink();
+
+create trigger tg_chkbacklink before insert or update
+    on PLine for each row execute procedure tg_chkbacklink();
+
+
+-- ************************************************************
+-- * BEFORE UPDATE on PSlot
+-- *	- do delete/insert instead of update if name changes
+-- ************************************************************
+create function tg_pslot_bu() returns opaque as '
+begin
+    if new.slotname != old.slotname then
+        delete from PSlot where slotname = old.slotname;
+	insert into PSlot (
+		    slotname,
+		    pfname,
+		    slotlink,
+		    backlink
+		) values (
+		    new.slotname,
+		    new.pfname,
+		    new.slotlink,
+		    new.backlink
+		);
+        return null;
+    end if;
+    return new;
+end;
+' language 'plpgsql';
+
+create trigger tg_pslot_bu before update
+    on PSlot for each row execute procedure tg_pslot_bu();
+
+
+-- ************************************************************
+-- * BEFORE UPDATE on WSlot
+-- *	- do delete/insert instead of update if name changes
+-- ************************************************************
+create function tg_wslot_bu() returns opaque as '
+begin
+    if new.slotname != old.slotname then
+        delete from WSlot where slotname = old.slotname;
+	insert into WSlot (
+		    slotname,
+		    roomno,
+		    slotlink,
+		    backlink
+		) values (
+		    new.slotname,
+		    new.roomno,
+		    new.slotlink,
+		    new.backlink
+		);
+        return null;
+    end if;
+    return new;
+end;
+' language 'plpgsql';
+
+create trigger tg_wslot_bu before update
+    on WSlot for each row execute procedure tg_Wslot_bu();
+
+
+-- ************************************************************
+-- * BEFORE UPDATE on PLine
+-- *	- do delete/insert instead of update if name changes
+-- ************************************************************
+create function tg_pline_bu() returns opaque as '
+begin
+    if new.slotname != old.slotname then
+        delete from PLine where slotname = old.slotname;
+	insert into PLine (
+		    slotname,
+		    phonenumber,
+		    comment,
+		    backlink
+		) values (
+		    new.slotname,
+		    new.phonenumber,
+		    new.comment,
+		    new.backlink
+		);
+        return null;
+    end if;
+    return new;
+end;
+' language 'plpgsql';
+
+create trigger tg_pline_bu before update
+    on PLine for each row execute procedure tg_pline_bu();
+
+
+-- ************************************************************
+-- * BEFORE UPDATE on IFace
+-- *	- do delete/insert instead of update if name changes
+-- ************************************************************
+create function tg_iface_bu() returns opaque as '
+begin
+    if new.slotname != old.slotname then
+        delete from IFace where slotname = old.slotname;
+	insert into IFace (
+		    slotname,
+		    sysname,
+		    ifname,
+		    slotlink
+		) values (
+		    new.slotname,
+		    new.sysname,
+		    new.ifname,
+		    new.slotlink
+		);
+        return null;
+    end if;
+    return new;
+end;
+' language 'plpgsql';
+
+create trigger tg_iface_bu before update
+    on IFace for each row execute procedure tg_iface_bu();
+
+
+-- ************************************************************
+-- * BEFORE UPDATE on HSlot
+-- *	- do delete/insert instead of update if name changes
+-- ************************************************************
+create function tg_hslot_bu() returns opaque as '
+begin
+    if new.slotname != old.slotname or new.hubname != old.hubname then
+        delete from HSlot where slotname = old.slotname;
+	insert into HSlot (
+		    slotname,
+		    hubname,
+		    slotno,
+		    slotlink
+		) values (
+		    new.slotname,
+		    new.hubname,
+		    new.slotno,
+		    new.slotlink
+		);
+        return null;
+    end if;
+    return new;
+end;
+' language 'plpgsql';
+
+create trigger tg_hslot_bu before update
+    on HSlot for each row execute procedure tg_hslot_bu();
+
+
+-- ************************************************************
+-- * BEFORE UPDATE on PHone
+-- *	- do delete/insert instead of update if name changes
+-- ************************************************************
+create function tg_phone_bu() returns opaque as '
+begin
+    if new.slotname != old.slotname then
+        delete from PHone where slotname = old.slotname;
+	insert into PHone (
+		    slotname,
+		    comment,
+		    slotlink
+		) values (
+		    new.slotname,
+		    new.comment,
+		    new.slotlink
+		);
+        return null;
+    end if;
+    return new;
+end;
+' language 'plpgsql';
+
+create trigger tg_phone_bu before update
+    on PHone for each row execute procedure tg_phone_bu();
+
+
+-- ************************************************************
+-- * AFTER INSERT or UPDATE or DELETE on slot with backlink
+-- *	- Ensure that the opponent correctly points back to us
+-- ************************************************************
+create function tg_backlink_a() returns opaque as '
+declare
+    dummy	integer;
+begin
+    if tg_op = ''INSERT'' then
+        if new.backlink != '''' then
+	    dummy := tg_backlink_set(new.backlink, new.slotname);
+	end if;
+	return new;
+    end if;
+    if tg_op = ''UPDATE'' then
+        if new.backlink != old.backlink then
+	    if old.backlink != '''' then
+	        dummy := tg_backlink_unset(old.backlink, old.slotname);
+	    end if;
+	    if new.backlink != '''' then
+	        dummy := tg_backlink_set(new.backlink, new.slotname);
+	    end if;
+	else
+	    if new.slotname != old.slotname and new.backlink != '''' then
+	        dummy := tg_slotlink_set(new.backlink, new.slotname);
+	    end if;
+	end if;
+	return new;
+    end if;
+    if tg_op = ''DELETE'' then
+        if old.backlink != '''' then
+	    dummy := tg_backlink_unset(old.backlink, old.slotname);
+	end if;
+	return old;
+    end if;
+end;
+' language 'plpgsql';
+
+
+create trigger tg_backlink_a after insert or update or delete
+    on PSlot for each row execute procedure tg_backlink_a('PS');
+
+create trigger tg_backlink_a after insert or update or delete
+    on WSlot for each row execute procedure tg_backlink_a('WS');
+
+create trigger tg_backlink_a after insert or update or delete
+    on PLine for each row execute procedure tg_backlink_a('PL');
+
+
+-- ************************************************************
+-- * Support function to set the opponents backlink field
+-- * if it does not already point to the requested slot
+-- ************************************************************
+create function tg_backlink_set(bpchar, bpchar)
+returns integer as '
+declare
+    myname	alias for $1;
+    blname	alias for $2;
+    mytype	char(2);
+    link	char(4);
+    rec		record;
+begin
+    mytype := substr(myname, 1, 2);
+    link := mytype || substr(blname, 1, 2);
+    if link = ''PLPL'' then
+        raise exception 
+		''backlink between two phone lines does not make sense'';
+    end if;
+    if link in (''PLWS'', ''WSPL'') then
+        raise exception 
+		''direct link of phone line to wall slot not permitted'';
+    end if;
+    if mytype = ''PS'' then
+        select into rec * from PSlot where slotname = myname;
+	if not found then
+	    raise exception ''% does not exists'', myname;
+	end if;
+	if rec.backlink != blname then
+	    update PSlot set backlink = blname where slotname = myname;
+	end if;
+	return 0;
+    end if;
+    if mytype = ''WS'' then
+        select into rec * from WSlot where slotname = myname;
+	if not found then
+	    raise exception ''% does not exists'', myname;
+	end if;
+	if rec.backlink != blname then
+	    update WSlot set backlink = blname where slotname = myname;
+	end if;
+	return 0;
+    end if;
+    if mytype = ''PL'' then
+        select into rec * from PLine where slotname = myname;
+	if not found then
+	    raise exception ''% does not exists'', myname;
+	end if;
+	if rec.backlink != blname then
+	    update PLine set backlink = blname where slotname = myname;
+	end if;
+	return 0;
+    end if;
+    raise exception ''illegal backlink beginning with %'', mytype;
+end;
+' language 'plpgsql';
+
+
+-- ************************************************************
+-- * Support function to clear out the backlink field if
+-- * it still points to specific slot
+-- ************************************************************
+create function tg_backlink_unset(bpchar, bpchar)
+returns integer as '
+declare
+    myname	alias for $1;
+    blname	alias for $2;
+    mytype	char(2);
+    rec		record;
+begin
+    mytype := substr(myname, 1, 2);
+    if mytype = ''PS'' then
+        select into rec * from PSlot where slotname = myname;
+	if not found then
+	    return 0;
+	end if;
+	if rec.backlink = blname then
+	    update PSlot set backlink = '''' where slotname = myname;
+	end if;
+	return 0;
+    end if;
+    if mytype = ''WS'' then
+        select into rec * from WSlot where slotname = myname;
+	if not found then
+	    return 0;
+	end if;
+	if rec.backlink = blname then
+	    update WSlot set backlink = '''' where slotname = myname;
+	end if;
+	return 0;
+    end if;
+    if mytype = ''PL'' then
+        select into rec * from PLine where slotname = myname;
+	if not found then
+	    return 0;
+	end if;
+	if rec.backlink = blname then
+	    update PLine set backlink = '''' where slotname = myname;
+	end if;
+	return 0;
+    end if;
+end;
+' language 'plpgsql';
+
+
+-- ************************************************************
+-- * AFTER INSERT or UPDATE or DELETE on slot with slotlink
+-- *	- Ensure that the opponent correctly points back to us
+-- ************************************************************
+create function tg_slotlink_a() returns opaque as '
+declare
+    dummy	integer;
+begin
+    if tg_op = ''INSERT'' then
+        if new.slotlink != '''' then
+	    dummy := tg_slotlink_set(new.slotlink, new.slotname);
+	end if;
+	return new;
+    end if;
+    if tg_op = ''UPDATE'' then
+        if new.slotlink != old.slotlink then
+	    if old.slotlink != '''' then
+	        dummy := tg_slotlink_unset(old.slotlink, old.slotname);
+	    end if;
+	    if new.slotlink != '''' then
+	        dummy := tg_slotlink_set(new.slotlink, new.slotname);
+	    end if;
+	else
+	    if new.slotname != old.slotname and new.slotlink != '''' then
+	        dummy := tg_slotlink_set(new.slotlink, new.slotname);
+	    end if;
+	end if;
+	return new;
+    end if;
+    if tg_op = ''DELETE'' then
+        if old.slotlink != '''' then
+	    dummy := tg_slotlink_unset(old.slotlink, old.slotname);
+	end if;
+	return old;
+    end if;
+end;
+' language 'plpgsql';
+
+
+create trigger tg_slotlink_a after insert or update or delete
+    on PSlot for each row execute procedure tg_slotlink_a('PS');
+
+create trigger tg_slotlink_a after insert or update or delete
+    on WSlot for each row execute procedure tg_slotlink_a('WS');
+
+create trigger tg_slotlink_a after insert or update or delete
+    on IFace for each row execute procedure tg_slotlink_a('IF');
+
+create trigger tg_slotlink_a after insert or update or delete
+    on HSlot for each row execute procedure tg_slotlink_a('HS');
+
+create trigger tg_slotlink_a after insert or update or delete
+    on PHone for each row execute procedure tg_slotlink_a('PH');
+
+
+-- ************************************************************
+-- * Support function to set the opponents slotlink field
+-- * if it does not already point to the requested slot
+-- ************************************************************
+create function tg_slotlink_set(bpchar, bpchar)
+returns integer as '
+declare
+    myname	alias for $1;
+    blname	alias for $2;
+    mytype	char(2);
+    link	char(4);
+    rec		record;
+begin
+    mytype := substr(myname, 1, 2);
+    link := mytype || substr(blname, 1, 2);
+    if link = ''PHPH'' then
+        raise exception 
+		''slotlink between two phones does not make sense'';
+    end if;
+    if link in (''PHHS'', ''HSPH'') then
+        raise exception 
+		''link of phone to hub does not make sense'';
+    end if;
+    if link in (''PHIF'', ''IFPH'') then
+        raise exception 
+		''link of phone to hub does not make sense'';
+    end if;
+    if link in (''PSWS'', ''WSPS'') then
+        raise exception 
+		''slotlink from patchslot to wallslot not permitted'';
+    end if;
+    if mytype = ''PS'' then
+        select into rec * from PSlot where slotname = myname;
+	if not found then
+	    raise exception ''% does not exists'', myname;
+	end if;
+	if rec.slotlink != blname then
+	    update PSlot set slotlink = blname where slotname = myname;
+	end if;
+	return 0;
+    end if;
+    if mytype = ''WS'' then
+        select into rec * from WSlot where slotname = myname;
+	if not found then
+	    raise exception ''% does not exists'', myname;
+	end if;
+	if rec.slotlink != blname then
+	    update WSlot set slotlink = blname where slotname = myname;
+	end if;
+	return 0;
+    end if;
+    if mytype = ''IF'' then
+        select into rec * from IFace where slotname = myname;
+	if not found then
+	    raise exception ''% does not exists'', myname;
+	end if;
+	if rec.slotlink != blname then
+	    update IFace set slotlink = blname where slotname = myname;
+	end if;
+	return 0;
+    end if;
+    if mytype = ''HS'' then
+        select into rec * from HSlot where slotname = myname;
+	if not found then
+	    raise exception ''% does not exists'', myname;
+	end if;
+	if rec.slotlink != blname then
+	    update HSlot set slotlink = blname where slotname = myname;
+	end if;
+	return 0;
+    end if;
+    if mytype = ''PH'' then
+        select into rec * from PHone where slotname = myname;
+	if not found then
+	    raise exception ''% does not exists'', myname;
+	end if;
+	if rec.slotlink != blname then
+	    update PHone set slotlink = blname where slotname = myname;
+	end if;
+	return 0;
+    end if;
+    raise exception ''illegal slotlink beginning with %'', mytype;
+end;
+' language 'plpgsql';
+
+
+-- ************************************************************
+-- * Support function to clear out the slotlink field if
+-- * it still points to specific slot
+-- ************************************************************
+create function tg_slotlink_unset(bpchar, bpchar)
+returns integer as '
+declare
+    myname	alias for $1;
+    blname	alias for $2;
+    mytype	char(2);
+    rec		record;
+begin
+    mytype := substr(myname, 1, 2);
+    if mytype = ''PS'' then
+        select into rec * from PSlot where slotname = myname;
+	if not found then
+	    return 0;
+	end if;
+	if rec.slotlink = blname then
+	    update PSlot set slotlink = '''' where slotname = myname;
+	end if;
+	return 0;
+    end if;
+    if mytype = ''WS'' then
+        select into rec * from WSlot where slotname = myname;
+	if not found then
+	    return 0;
+	end if;
+	if rec.slotlink = blname then
+	    update WSlot set slotlink = '''' where slotname = myname;
+	end if;
+	return 0;
+    end if;
+    if mytype = ''IF'' then
+        select into rec * from IFace where slotname = myname;
+	if not found then
+	    return 0;
+	end if;
+	if rec.slotlink = blname then
+	    update IFace set slotlink = '''' where slotname = myname;
+	end if;
+	return 0;
+    end if;
+    if mytype = ''HS'' then
+        select into rec * from HSlot where slotname = myname;
+	if not found then
+	    return 0;
+	end if;
+	if rec.slotlink = blname then
+	    update HSlot set slotlink = '''' where slotname = myname;
+	end if;
+	return 0;
+    end if;
+    if mytype = ''PH'' then
+        select into rec * from PHone where slotname = myname;
+	if not found then
+	    return 0;
+	end if;
+	if rec.slotlink = blname then
+	    update PHone set slotlink = '''' where slotname = myname;
+	end if;
+	return 0;
+    end if;
+end;
+' language 'plpgsql';
+
+

src/pl/plpgsql/test/views.sql

+-- ************************************************************
+-- * Describe the backside of a patchfield slot
+-- ************************************************************
+create function pslot_backlink_view(bpchar)
+returns text as '
+<<outer>>
+declare
+    rec		record;
+    bltype	char(2);
+    retval	text;
+begin
+    select into rec * from PSlot where slotname = $1;
+    if not found then
+        return '''';
+    end if;
+    if rec.backlink = '''' then
+        return ''-'';
+    end if;
+    bltype := substr(rec.backlink, 1, 2);
+    if bltype = ''PL'' then
+        declare
+	    rec		record;
+	begin
+	    select into rec * from PLine where slotname = outer.rec.backlink;
+	    retval := ''Phone line '' || trim(rec.phonenumber);
+	    if rec.comment != '''' then
+	        retval := retval || '' ('';
+		retval := retval || rec.comment;
+		retval := retval || '')'';
+	    end if;
+	    return retval;
+	end;
+    end if;
+    if bltype = ''WS'' then
+        select into rec * from WSlot where slotname = rec.backlink;
+	retval := trim(rec.slotname) || '' in room '';
+	retval := retval || trim(rec.roomno);
+	retval := retval || '' -> '';
+	return retval || wslot_slotlink_view(rec.slotname);
+    end if;
+    return rec.backlink;
+end;
+' language 'plpgsql';
+
+
+-- ************************************************************
+-- * Describe the front of a patchfield slot
+-- ************************************************************
+create function pslot_slotlink_view(bpchar)
+returns text as '
+declare
+    psrec	record;
+    sltype	char(2);
+    retval	text;
+begin
+    select into psrec * from PSlot where slotname = $1;
+    if not found then
+        return '''';
+    end if;
+    if psrec.slotlink = '''' then
+        return ''-'';
+    end if;
+    sltype := substr(psrec.slotlink, 1, 2);
+    if sltype = ''PS'' then
+	retval := trim(psrec.slotlink) || '' -> '';
+	return retval || pslot_backlink_view(psrec.slotlink);
+    end if;
+    if sltype = ''HS'' then
+        retval := comment from Hub H, HSlot HS
+			where HS.slotname = psrec.slotlink
+			  and H.name = HS.hubname;
+        retval := retval || '' slot '';
+	retval := retval || slotno::text from HSlot
+			where slotname = psrec.slotlink;
+	return retval;
+    end if;
+    return psrec.slotlink;
+end;
+' language 'plpgsql';
+
+
+-- ************************************************************
+-- * Describe the front of a wall connector slot
+-- ************************************************************
+create function wslot_slotlink_view(bpchar)
+returns text as '
+declare
+    rec		record;
+    sltype	char(2);
+    retval	text;
+begin
+    select into rec * from WSlot where slotname = $1;
+    if not found then
+        return '''';
+    end if;
+    if rec.slotlink = '''' then
+        return ''-'';
+    end if;
+    sltype := substr(rec.slotlink, 1, 2);
+    if sltype = ''PH'' then
+        select into rec * from PHone where slotname = rec.slotlink;
+	retval := ''Phone '' || trim(rec.slotname);
+	if rec.comment != '''' then
+	    retval := retval || '' ('';
+	    retval := retval || rec.comment;
+	    retval := retval || '')'';
+	end if;
+	return retval;
+    end if;
+    if sltype = ''IF'' then
+	declare
+	    syrow	System%RowType;
+	    ifrow	IFace%ROWTYPE;
+        begin
+	    select into ifrow * from IFace where slotname = rec.slotlink;
+	    select into syrow * from System where name = ifrow.sysname;
+	    retval := syrow.name || '' IF '';
+	    retval := retval || ifrow.ifname;
+	    if syrow.comment != '''' then
+	        retval := retval || '' ('';
+		retval := retval || syrow.comment;
+		retval := retval || '')'';
+	    end if;
+	    return retval;
+	end;
+    end if;
+    return rec.slotlink;
+end;
+' language 'plpgsql';
+
+
+
+-- ************************************************************
+-- * View of a patchfield describing backside and patches
+-- ************************************************************
+create view Pfield_v1 as select PF.pfname, PF.slotname,
+	pslot_backlink_view(PF.slotname) as backside,
+	pslot_slotlink_view(PF.slotname) as patch
+    from PSlot PF;
+
+