Four triggers: It does not work - triggers

Question

Hello everybody,
excuse me for my bad english
It's been more than 4 days I am trying to solve my problem:
each trigger works well but when I combine them there is an error:
the subquery returns more than 1 value.
I tried to follow all the tips in this website and others, I could not make it works, though.
the concerned tables are: PIECES, COMPOSITIONSGAMMES, nomenclatures and SITUATIONS.
What I want the triggers to do is :
When the user inserts a new row on "SITUATIONS" and if 'nomstrategie'= "DST" (It's a name of a strategy but this detail does not really matter, I mean for people who will help me), I need other rows to be inserted with the same reference (referencepiece), the same strategy(nomstrategie). Only 'ancienposte' and 'nouveauposte' have to change. Indeed, the first one's value(s) has to be all 'Numeroposte' from the table "Compositionsgammes". The second one's value has to be '???'.
I need, when I insert a new row and 'nomstrategie'='DST', other rows to be inserted with all 'piecesfilles' in the table "Nomenclatures"
of the reference 'referencepiece' in the row inserted by the user. And in 'ancienposte', there should be 'numeroposte' in the table "compositionsgammes".
I need, when the user inserts a new row and 'nomstrategie'= 'delestage, another row to be inserted as below, for example :
inserted row: Ref A ancienposte : P01 Nouveauposte :P02 Nomstrategie :Delestage…………
row to be inserted: Ref A ancienposte : P02 Nouveauposte :NULL Nomstrategie :Delestage…………
I need, for every row in the table "situations", calculate a value called 'charge' in the table situations charge=(TS/Taillelot)+Tu
here are the triggers I've done:
create trigger [dbo].[ALLDST]
ON [dbo].[SITUATIONS]
AFTER INSERT /*pas d'update*/
as
begin
set nocount on
insert into SITUATIONS(ReferencePiece,nomstrategie,AncienPoste,nouveauposte,DateStrategie)
select distinct i.referencepiece, i.nomstrategie,COMPOSITIONSGAMMES.NumeroPoste,'???',i.DateStrategie
from inserted i, PIECES, compositionsgammes, SITUATIONS s
where i.ReferencePiece is not null
and i.NomStrategie='DST'
and i.ReferencePiece=pieces.ReferencePiece and pieces.CodeGamme=COMPOSITIONSGAMMES.CodeGamme
and i.AncienPoste<>COMPOSITIONSGAMMES.NumeroPoste
and i.DateStrategie=s.DateStrategie
end
create trigger [dbo].[Calcul_Charge]
on [charges].[dbo].[SITUATIONS]
after insert
as
begin
update situations
set charge= (select (cg.TS/pieces.TailleLot)+cg.tu from situations s
inner join COMPOSITIONSGAMMES cg on cg.NumeroPoste=SITUATIONS.AncienPoste
inner join pieces on SITUATIONS.ReferencePiece=pieces.ReferencePiece
inner join inserted i on s.DateStrategie=i.DateStrategie
where cg.CodeGamme=pieces.CodeGamme and NumeroPoste=situations.AncienPoste
)
end
create trigger [dbo].[Duplicate_SITUATIONS]
ON [dbo].[SITUATIONS]
AFTER INSERT
as
begin
set nocount on
declare #ref varchar(50)
declare #strategie varchar(50)
declare #ancienposte varchar(50)
declare #datestrategie date
declare #pourcentage decimal(18,3)
declare #coeff decimal(18,3)
declare #charge decimal(18,3)
/*while (select referencepiece from situations where ReferencePiece) is not null*/
select #ref=referencepiece, #strategie=nomstrategie,#ancienposte=NouveauPoste,
#datestrategie=datestrategie, #pourcentage=PourcentageStrategie,#coeff=coeffameliorationposte,#charge=charge
from inserted,POSTESDECHARGE
where ReferencePiece is not null
and POSTESDECHARGE.NumeroPoste = inserted.AncienPoste
if #strategie = 'delestage' and #ancienposte is not null
/*if GETDATE()>= (select datestrategie from SITUATIONS)*/
begin
insert into SITUATIONS(ReferencePiece, nomstrategie,AncienPoste,DateStrategie,
StatutStrategie,DateModification,PourcentageStrategie,charge)
values
(#ref, #strategie, #ancienposte, #datestrategie,1,getdate(),#pourcentage,#charge*#coeff)
end
end

Answer 1

I'm mostly familiar with T-SQL (MS SQL), not sure if this will work for your case.. but I usually avoid updates using a sub query and rewrite your update:
update situations
set charge= (select (cg.TS/pieces.TailleLot)+cg.tu from situations s
inner join COMPOSITIONSGAMMES cg on cg.NumeroPoste=SITUATIONS.AncienPoste
inner join pieces on SITUATIONS.ReferencePiece=pieces.ReferencePiece
inner join inserted i on s.DateStrategie=i.DateStrategie
where cg.CodeGamme=pieces.CodeGamme and NumeroPoste=situations.AncienPoste
)
as follows
update s set
charge= (cg.TS/pieces.TailleLot)+cg.tu
from situations s
inner join COMPOSITIONSGAMMES cg on cg.NumeroPoste=SITUATIONS.AncienPoste
inner join pieces on SITUATIONS.ReferencePiece=pieces.ReferencePiece
inner join inserted i on s.DateStrategie=i.DateStrategie
where cg.CodeGamme=pieces.CodeGamme and NumeroPoste=situations.AncienPoste