从db显示文本框中的值 [英] Display a value in textbox from db

问题描述

我们如何在文本框中实现最高值，在页面加载中增加1



我尝试过：

How can we implement a highest value in textbox which is increment by 1 in page load

What I have tried:

protected void Page_Load(object sender, EventArgs e)
{
if (!this.Page.User.Identity.IsAuthenticated)
            {
                FormsAuthentication.RedirectToLoginPage();
            }
            txt_id= ('SELECT MAX(unitid) + 1  from tblunitmaster');
}

推荐答案

我们不能像上面的逻辑那样做。如果您在页面加载中编写代码而没有任何条件，那么当您回发时它将被执行。



步骤1：在回发后第1次验证是否它是一个登录或回发。

步骤2：然后从数据库中获取值并在本地变量/ Session中设置它并增加数据库中的计数。

步骤3：将此逻辑分成另一个类或函数，以确保代码清晰可读。

We cannot do like the above logic. If you write the code in the page load with out any conditions then when ever you post back it will be executed.

Step 1 : In post-back 1st verify if it is a login or a post back.
Step 2 : Then get the value from the Database and set that in a local variable/Session and increase the count in the database.
Step 3 : Separate this logic into a another class or a function to make sure the code is clean and readable.

txt_id= ('SELECT MAX(unitid) + 1 from tblunitmaster');

- >你必须使用SQL服务器连接来连接数据库。



如果这个dint解决了你的目的请回复并解释你的要求。清晰。在此先感谢：）

--> you have to use SQL server connection to connect to the database.

If this dint solve your purpose please reply and explain you req. clearly. Thanks in advance :)

使用 ExecuteScalar [ ^ ]从数据库读取数据并在任何UI控件上显示。

查看 Page.IsPostBack Property [ ^ ]自 page_Load 当页面中有回发时会触发事件，而后者会增加文本框中的值。

use ExecuteScalar [^] to read the data from db and display it on any UI control.
have a look on Page.IsPostBack Property [^] since the page_Load event will be fired when there is post back in the page which in turn, will increment the value in the textbox.

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