plpgsql.sql

postgresql8.3.4源码,开源数据库

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 trigger 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 trigger 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 trigger 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 trigger 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 trigger 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 trigger 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 trigger 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(myname bpchar, blname bpchar)
returns integer as '
declare
    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 exist'', 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 exist'', 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 exist'', 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 trigger 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 exist'', 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 exist'', 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 exist'', 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 exist'', 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 exist'', myname;
	end if;