需要帮忙 ！！数据未保存在sql server数据库中。 [英] Need help !! Data is not being saved on the sql server database.

问题描述

Imports System.Data.Sql
Imports System.Data.SqlClient
Public Class Form1
    Dim cnn As New SqlConnection
    Dim cmd As New SqlCommand
   
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        cmd.Connection = cnn
        cmd = New SqlCommand("insert into info(id, address) values('" & TextBox1.Text & "','" & TextBox2.Text & "')", cnn)
        cmd.ExecuteNonQuery()
        MsgBox("data saved successfully.")

        cnn.Close()

    End Sub

    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        cnn.ConnectionString = "Data Source=.\SQLEXPRESS;AttachDbFilename=" & Application.StartupPath & "\Database1.mdf; Integrated Security=True;User Instance=True"
        cnn.Open()
    End Sub
End Class

我是否需要添加更多数据才能将数据从文本框保存到数据库？

Do I need to add more to save the data from the textboxes to database?

推荐答案

0）请把所有的数据访问代码在一个单独的类 - 数据访问层。

1）请使用参数化查询; 不使用连接来形成您的查询。

2）不要打开连接并在申请期间保持打开状态。

3）使用try / finally

4）你的点击将关闭连接，第二次点击将失败。



除此之外，它看起来很好。

0) Please put all the data access code in a separate class -- a Data Access Layer.
1) Please use a parameterized query; do not use concatenation to form your queries.
2) Do not open the connection and leave it open for the duration of the application.
3) Use a try/finally
4) Your click will close the connection and a second click will fail.

Other than that, it looks fine.

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