Hello, I am having the following problem

Multiple rows to insert:
---------------------
insert into Customer(CustomerId,Name,Value)
select CustomerId,Name,Value
from CustomerTemp

Trigger in Customer table that invoke a function:
---------------------------------------------
alter TRIGGER [dbo].[Calculation] ON [dbo].[Customer]
AFTER INSERT
AS

update Customer
set Percentage = dbo.GetPercentage((select Value from inserted))
where CustomerId = (select CustomerId from inserted)


I'm getting the error for the multiple row.
Subquery returned more than 1 value. This is not permitted when the subquery follows =, !=, <, <= , >, >= or when the subquery is used as an expression.

Is there a way to let me insert multiple rows, using the trigger that invoke a function ?
I am reading regarding cursor.

Please, thanks in advance for any help,

Regards, Paul.-

Replace "update Customer
set Percentage = dbo.GetPercentage((select Value from inserted))
where CustomerId = (select CustomerId from inserted)" by GetPercentage(), is that a User Defined Function?

But forget the trigger. Have a look at computed columns. I think that is what you really need.