Trigger before Insert

CREATE TABLE Employee_Test
(
Emp_ID INT Identity,
Emp_name Varchar(100),
Emp_Sal Decimal (10,2),
alldata nvarchar(100) not null
--allData as Convert(varchar(10), [Emp_ID]) +'|'+ Emp_name +'|'+Convert(varchar(10), Emp_sal)
)




create TRIGGER trgInsteadOfinsert ON Employee_Test
INSTEAD OF insert
AS
	declare @id int;
	declare @nm Varchar(100);
	declare @Sal Decimal (10,2);
	declare @adata nvarchar(100);
	
	select @id = max(et.Emp_Id) from Employee_Test et;
	--set @nm = convert(varchar(10),@id);
	if(isnumeric(@id) = 0)
	begin
	set @id= 1;
	end
	else
	begin
    Set @id = @id+1;  
	end	
	select @nm = i.Emp_Name from inserted i;
	select @Sal = i.Emp_Sal from inserted i;
	select @adata= Convert(nvarchar(100),@id)+'|'+i.Emp_name+'|'+Convert(nvarchar(100),i.Emp_sal)
	 from inserted i;
	
	BEGIN
	
	INSERT INTO Employee_Test VALUES (@nm,@Sal,@adata);
	END
GO

INSERT INTO Employee_Test(Emp_name,Emp_Sal) VALUES ('ravi',1000);
INSERT INTO Employee_Test(Emp_name,Emp_Sal) VALUES ('kishan',1200);
INSERT INTO Employee_Test(Emp_name,Emp_Sal) VALUES ('pradeep',1100);


select * from Employee_Test