尝试插入数据时ConfigurationManager出错

Question

所以我试图将数据添加到MySQL服务器数据库。

下面是代码：

Imports System.Data 
Imports System.Data.SqlClient 

Partial Class _Default 
    Inherits System.Web.UI.Page 

    Protected Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click 
     Dim conn As String = ConfigurationManager.ConnectionStrings("Data Source=JOAOCOQUIM\SQLEXPRESS;Initial Catalog=Teste;Integrated Security=True").ConnectionString 
     Dim connection As SqlConnection = New SqlConnection(conn) 
     Dim sql As String = "Insert into [User] ([nome], [idade]) values (@nome, @idade)" 
     Dim cmd As SqlCommand = New SqlCommand(sql, connection) 
     cmd.Parameters.AddWithValue("@nome", TextBox1.Text) 
     cmd.Parameters.AddWithValue("@idade", TextBox2.Text) 


     connection.Open() 
     cmd.ExecuteNonQuery() 
     connection.Close() 
    End Sub 
End Class` 

当我插入数据，然后单击Button显示它的我下面的错误：

Answer 1

所以，我没有说什么错误，它工作。

这里的工作代码：

Imports System.Data 
Imports System.Data.SqlClient 

Partial Class _Default 
    Inherits System.Web.UI.Page 

    Protected Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click 
     Dim conn As SqlConnection = New SqlConnection("Data Source=JOAOCOQUIM\SQLEXPRESS;Initial Catalog=Teste;Integrated Security=True") 
     Dim connection As SqlConnection = New SqlConnection("Data Source=JOAOCOQUIM\SQLEXPRESS;Initial Catalog=Teste;Integrated Security=True") 
     Dim sql As String = "Insert into [User] ([nome], [idade]) values (@nome, @idade)" 
     Dim cmd As SqlCommand = New SqlCommand(sql, connection) 
     cmd.Parameters.AddWithValue("@nome", TextBox1.Text) 
     cmd.Parameters.AddWithValue("@idade", TextBox2.Text) 


     connection.Open() 
     cmd.ExecuteNonQuery() 
     connection.Close() 
    End Sub 
End Class