SQL Server Trigger not Working - sql

Question

i have this 2 triggers and no one is working, but i dont know why, can´t everyone help me:
Insert:
CREATE TRIGGER [dbo].[afterInsert]
ON [dbo].[LinhasVenda]
FOR INSERT
AS
BEGIN
DECLARE
#IdVenda INT,
#PrecoTotalSIva MONEY,
#PrecoTotalCIva MONEY
SELECT
#PrecoTotalSIva = PrecoTotalSIva,
#PrecoTotalCIva = PrecoTotalCIva
FROM
INSERTED
UPDATE Vendas SET ValorSIva = ValorSIva + #PrecoTotalSIva,
ValorCIva = ValorCIva + #PrecoTotalCIva WHERE
IdVenda = #IdVenda
END
Delete:
CREATE TRIGGER afterDelete
ON LinhasVenda
FOR DELETE
AS
BEGIN
DECLARE
#IdVenda INT,
#IdArtifo INT,
#PrecoTotalSIva MONEY,
#PrecoTotalCIva MONEY
SELECT
#PrecoTotalSIva = PrecoTotalSIva,
#PrecoTotalCIva = PrecoTotalCIva
FROM
DELETED
UPDATE Vendas SET ValorSIva = ValorSIva - #PrecoTotalSIva,
ValorCIva = ValorCIva - #PrecoTotalCIva WHERE
IdVenda = #IdVenda
END

Answer 1

Both triggers have 2 flaws. The #IdVenda value used in the WHERE clause is not being assigned by the SELECT statements. Also, these triggers will not work with multi-row INSERT/UPDATE statements. I suggest you JOIN to INSERTED/DELETED, which will address both these problems. Below is an example, assuming the column name in the LinhasVenda table is also named IdVenda.
CREATE TRIGGER [dbo].[afterInsert]
ON [dbo].[LinhasVenda]
FOR INSERT
AS
BEGIN
UPDATE v
SET
ValorSIva = v.ValorSIva + i.PrecoTotalSIva
, ValorCIva = v.ValorCIva + i.PrecoTotalCIva
FROM Vendas AS v
JOIN INSERTED AS i ON
i.IdVenda = v.IdVenda;
END;
GO
CREATE TRIGGER afterDelete
ON LinhasVenda
FOR DELETE
AS
BEGIN
UPDATE v
SET
ValorSIva = v.ValorSIva - d.PrecoTotalSIva
, ValorCIva = v.ValorCIva - d.PrecoTotalCIva
FROM Vendas AS v
JOIN DELETED AS d ON
d.IdVenda = v.IdVenda;
END;
GO