triggers.out

关系型数据库 Postgresql 6.5.2

' language 'plpgsql';
QUERY: create trigger tg_hslot_bu before update
    on HSlot for each row execute procedure tg_hslot_bu();
QUERY: 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';
QUERY: create trigger tg_phone_bu before update
    on PHone for each row execute procedure tg_phone_bu();
QUERY: 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';
QUERY: create trigger tg_backlink_a after insert or update or delete
    on PSlot for each row execute procedure tg_backlink_a('PS');
QUERY: create trigger tg_backlink_a after insert or update or delete
    on WSlot for each row execute procedure tg_backlink_a('WS');
QUERY: create trigger tg_backlink_a after insert or update or delete
    on PLine for each row execute procedure tg_backlink_a('PL');
QUERY: 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';
QUERY: 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';
QUERY: 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';
QUERY: create trigger tg_slotlink_a after insert or update or delete
    on PSlot for each row execute procedure tg_slotlink_a('PS');
QUERY: create trigger tg_slotlink_a after insert or update or delete
    on WSlot for each row execute procedure tg_slotlink_a('WS');
QUERY: create trigger tg_slotlink_a after insert or update or delete
    on IFace for each row execute procedure tg_slotlink_a('IF');
QUERY: create trigger tg_slotlink_a after insert or update or delete
    on HSlot for each row execute procedure tg_slotlink_a('HS');
QUERY: create trigger tg_slotlink_a after insert or update or delete
    on PHone for each row execute procedure tg_slotlink_a('PH');
QUERY: 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';
QUERY: 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';