如何在WPF中使用SQL查询删除datagrid上的数据 [英] How to delete data on datagrid using SQL query in WPF

问题描述

当我点击删除按钮然后显示错误启用以投射数据对象

所以请解决此错误



什么我试过了：

when i click delete button then shows error enable to cast an data object
so please solve this error

What I have tried:

private void DeleteData_OnClick(object sender, RoutedEventArgs routedEventArgs)
{
    var selectedRow = MyDataGrid.SelectedItem;
    BookingRequest request = selectedRow as BookingRequest;
    long id = request.ID;
    con.Open();
    string query = "Delete from BookingRequest where ID ='"+ id +"'";
    SqlCommand sqlcmd = new SqlCommand(query, con);
    sqlcmd.ExecuteNonQuery();
    MessageBox.Show("Data deleted successfully");
    con.Close();
    Load();
}

推荐答案

query = "Delete from BookingRequest where ID ='"+ id +"'";

没有必要解决你的问题，但你有另一个问题。

永远不要建立通过连接字符串进行SQL查询。迟早，您将使用用户输入来执行此操作，这会打开一个名为SQL注入的漏洞，这对您的数据库很容易并且容易出错。

名称中的单引号你的程序崩溃。如果用户输入像Brian O'Conner这样的名称可能会使您的应用程序崩溃，那么这是一个SQL注入漏洞，崩溃是最少的问题，恶意用户输入，并且它被提升为具有所有凭据的SQL命令。

SQL注入 - 维基百科 [ ^ ]

SQL注入 [ ^ ]

按示例进行SQL注入攻击 [ ^ ]

PHP：SQL注入 - 手册 [ ^ ]

SQL注入预防备忘单 - OWASP [ ^ ]

我该怎么办？解释没有技术术语的SQL注入？ - 信息安全堆栈交换 [ ^ ]

Not necessary a solution to your question, but another problem you have.
Never build an SQL query by concatenating strings. Sooner or later, you will do it with user inputs, and this opens door to a vulnerability named "SQL injection", it is dangerous for your database and error prone.
A single quote in a name and your program crash. If a user input a name like "Brian O'Conner" can crash your app, it is an SQL injection vulnerability, and the crash is the least of the problems, a malicious user input and it is promoted to SQL commands with all credentials.
SQL injection - Wikipedia[^]
SQL Injection[^]
SQL Injection Attacks by Example[^]
PHP: SQL Injection - Manual[^]
SQL Injection Prevention Cheat Sheet - OWASP[^]
How can I explain SQL injection without technical jargon? - Information Security Stack Exchange[^]

private void DeleteData_OnClick(object sender, RoutedEventArgs routedEventArgs)
          {
              var selectedRow = MyDataGrid.SelectedItem;
              BookingRequest request = selectedRow as BookingRequest;
              long id = request.ID;
              con.Open();
              string query = "Delete from BookingRequest where ID ='"+ id +"'";
              SqlCommand sqlcmd = new SqlCommand(query, con);
              sqlcmd.ExecuteNonQuery();
              MessageBox.Show("Data deleted successfully");
              con.Close();
              Load();
                 }

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