Error handling 如何使用'；最后试试catch'；块以在成功执行mysql查询时显示消息

我在C#Windows窗体的代码中使用了“try-catch-finally”来查询MySQL数据库。代码运行良好：当catch块标记错误时，消息框将显示错误消息

在finally块中，我编写了一个消息框，它将在数据库成功更新时显示

如果没有错误消息，则一切正常。成功消息显示

但是，如果有错误，将在catch块中显示错误消息，然后在finally块中显示成功消息

有没有人知道一种解决方案，可以让程序在更新mysql时显示错误消息或成功消息

谢谢

彼得

下面是一个代码示例：

私有void btnUpdateEmployeeTable_单击（对象发送者，事件参数）//更新Employee表中的记录 { 字符串myConnection=@“服务器=localhost；数据库=shopdb；用户名=**；密码=**；转换零日期时间=True”； MySqlConnection=null

        try
        {
            Connect = new MySqlConnection(myConnection);
            Connect.Open(); //Open the connection

            //This is the mysql command that we will query into the db.
            //It uses Prepared statements and the Placeholders for faster, more secure processing.

            String updateQuery = "UPDATE employee SET emp_lName = @empLastName, emp_fName = @empFirstName WHERE emp_number = @empNum";

            MySqlCommand cmdInsertEmployeeToDataBase = new MySqlCommand(updateQuery, Connect);
            cmdInsertEmployeeToDataBase.Prepare();

            //Bind the value to the placeholder               

            cmdInsertEmployeeToDataBase.Parameters.AddWithValue("@empNum", this.txtEmployeeNo.Text);
            cmdInsertEmployeeToDataBase.Parameters.AddWithValue("@empLastName", this.txtEmployeeLastName.Text);
            cmdInsertEmployeeToDataBase.Parameters.AddWithValue("@empFirstName", this.txtEmployeeFirstName.Text);                

            cmdInsertEmployeeToDataBase.ExecuteNonQuery(); //Execute the mysql command 


        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message + "\nDatabase could not be updated \n" + "Please try again");

        }
        finally
        {
            if (Connect != null)
            {
                Connect.Close(); //Close the connection
            }


            MessageBox.Show("Database update successful");


        }
    }

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您可以轻松地将成功代码向上移动。如果在

MessageBox.Show（“Database update successful”）；

行之前抛出异常，则它将永远不会执行

     try
     {
        Connect = new MySqlConnection(myConnection);
        Connect.Open(); //Open the connection

        //This is the mysql command that we will query into the db.
        //It uses Prepared statements and the Placeholders for faster, more secure processing.

        String updateQuery = "UPDATE employee SET emp_lName = @empLastName, emp_fName = @empFirstName WHERE emp_number = @empNum";

        MySqlCommand cmdInsertEmployeeToDataBase = new MySqlCommand(updateQuery, Connect);
        cmdInsertEmployeeToDataBase.Prepare();

        //Bind the value to the placeholder               

        cmdInsertEmployeeToDataBase.Parameters.AddWithValue("@empNum", this.txtEmployeeNo.Text);
        cmdInsertEmployeeToDataBase.Parameters.AddWithValue("@empLastName", this.txtEmployeeLastName.Text);
        cmdInsertEmployeeToDataBase.Parameters.AddWithValue("@empFirstName", this.txtEmployeeFirstName.Text);

        cmdInsertEmployeeToDataBase.ExecuteNonQuery(); //Execute the mysql command 

        MessageBox.Show("Database update successful");

     }
     catch (Exception ex)
     {
        MessageBox.Show(ex.Message + "\nDatabase could not be updated \n" + "Please try again");

     }
     finally
     {
        if (Connect != null)
        {
           Connect.Close(); //Close the connection
        }

     }

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工作灯的魅力！简单，精彩的解决方案。谢谢！！