Make Calculations in Sql Server Database

Question

I am making an application with Sql Server database and I want the database to work the calculations and not the application, but I’m having difficulties to do, I hope someone can help me in this issue.

These are the columns of the Product table, the data were entered manually, the columns Totalbuy and Totalsell are computed (Stock * Purchase price) and (Stock * Sale price), respectively. Now comes the difficulty, I want the value in the column Profit is also automatic being (Totalsale -Totalpurchase)

I made the following Insert Procedure:

Answer 1

ALTER TABLE Produto
ADD Lucro AS ((ValorVenda - ValorCompra) * Estoque);

Answer 2

I don’t quite understand what you want, but you can use SUM to display this information whenever you need, without having to store the total.

SELECT Sum(VALOR_COMPRA - VALOR_VENDA) FROM ... ;

Or you can insert it simply and quickly, just like in this example:

INSERT INTO TESTE (valorcompra, valorvenda, lucro) VALUES (155,195, valorvenda - valorcompra)

I believe I can also use inside the Procedure!

values {
...
...
@VALOR_COMPRA, 
@VALOR_VENDA,
Lucro = @VALOR_COMPRA - @VALOR_VENDA

}