Run the following code.

create table demo(id int primarykey,number nvarchar(max))

go

create trigger dbodemo

on dbo.demo

for insert

as begin

declare @pk Nvarchar(max)

declare @pkey nvarchar(max)

declare @str nvarchar(max)

select @pk = column_name from INFORMATION_SCHEMA.KEY_COLUMN_USAGE where TABLE_NAME = 'demo'

select @pkey...