这是4个不同的问题：

- 如何对我的SQL基础做一个请求。

- 如何获得请求的结果。

- 如何添加2个值从结果。

- 如何在TextBox中放置一个值。



哪一个对你有问题？

你做了什么？



如果什么也没做，你的分析方法有问题吗？

SELECT P_id，P_price，P_interest，P_barcode，（P_price + P_interest） as T_price tbproduct

然后你可以设置T_price val即文本框文本

I have a table named tbproduct (P_id,P_price,P_interest,P_barcode) i want to add the values from P_price and P_interest and display it in a textbox for example if P_price is 100 and P_interest is 20 then the textbox should display 120
i have no idea how to do that
thank you!

That is 4 different questions:
- How to do a request to my SQL base.
- How to get the result of the request.
- How to add 2 value from the result.
- How to put a value in TextBox.

Which one is a problem for you ?
What have you done ?

If done nothing, do you have a problem with your analyse method ?

SELECT P_id,P_price,P_interest,P_barcode, ( P_price+ P_interest) as T_price  tbproduct

then you can set T_price value as textbox text