如何通过 VB 将数据“插入”到数据库中答案

【问题标题】：How to 'insert' data into database via VB如何通过 VB 将数据“插入”到数据库中
【发布时间】：2013-04-23 04:09:03
【问题描述】：

在这里有点挣扎。尝试开发代码以将用户输入链接到我的数据库中，以书籍记录的形式。例如，会要求用户输入他们的姓名地址等。但我使用的代码似乎没有执行，因为我不断收到相同的错误。

Line 12:         Dim con As New SqlConnection
Line 13:         Dim inscmd As New SqlCommand
Line 14:         con.ConnectionString = System.Configuration.ConfigurationManager.ConnectionStrings("Database.My.MySettings.Database1ConnectionString1").ConnectionString
Line 15:         con.Open()
Line 16:         inscmd.CommandText = ("insert into booking values('" + txtfirstname.Text + "', " + txtSurname.Text + "', " + txtAddressline1.Text + "', " + txtAddressline2.Text + "', " + txtPostcode.Text + "', " + txtTime.Text + "', " + txtPeople.Text + "', " + txtDropoff1.Text + "', " + txtDropoff2.Text + "', " + txtDropoffpost.Text + "")

第 14 行包含错误，但我不知道为什么。这是我的代码；

Protected Sub btnsubmit_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles  btnsubmit.Click
    Dim con As New SqlConnection
    Dim inscmd As New SqlCommand
    con.ConnectionString = System.Configuration.ConfigurationManager.ConnectionStrings("Database.My.MySettings.Database1ConnectionString1").ConnectionString
    con.Open()
    inscmd.CommandText = ("insert into booking values('" + txtfirstname.Text + "', " + txtSurname.Text + "', " + txtAddressline1.Text + "', " + txtAddressline2.Text + "', " + txtPostcode.Text + "', " + txtTime.Text + "', " + txtPeople.Text + "', " + txtDropoff1.Text + "', " + txtDropoff2.Text + "', " + txtDropoffpost.Text + "")
    Print(inscmd.CommandText)
    inscmd.Connection = con
    inscmd.ExecuteNonQuery()
    con.Close()
    inscmd.Parameters.Clear()

    MsgBox("Your booking has been successfully")
    con.Close()

End Sub

【问题讨论】：

错误是什么？您的 web.config 中的连接字符串实际上是否称为 "Database.My.MySettings.Database1ConnectionString1" ？
ConnectionString" connectionString="Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\Database.mdf;Integrated Security=True;User Instance=True" providerName="System.Data.SqlClient"/ > 这是它在我的网络配置文件中所说的吗？

标签： mysql sql vb.net vba

【解决方案1】：

希望这会对您有所帮助（在需要的地方插入您的代码）

        Dim con As New SqlConnection
        Dim myConString As String = getSQLString() ' GET YOUR CON String

' 我的函数返回时是这样的

"Server=ServerExactLocationPath;Database=DataBase;User Id=UserName;Password=Password;"

        Dim objcommand As SqlCommand = New SqlCommand
        'con.ConnectionString = myConString

        With objcommand
            .Connection = con
            Dim cmdText As String = ""
            cmdText = "Insert into SitesStatus (SiteNumber,StatusName,Date,ByUser) values ('" & site & "','" & status & "','" & System.DateTime.Today.ToString("MM/dd/yyyy") & "','" & dbUiInitials & "')"
        'PUT YOUR INSERT ABOVE

         .CommandText = cmdText
        End With
        con.ConnectionString = myConString
        con.Open()
        objcommand.ExecuteNonQuery()
        con.Close()

    Catch ex As Exception
      End Try
 Return Nothing

【讨论】：

【解决方案2】：

insert into booking values('" + txtfirstname.Text + "', " + txtSurname.Text + "', " + txtAddressline1.Text + "', " + txtAddressline2.Text + "', " + txtPostcode.Text + "', " + txtTime.Text + "', " + txtPeople.Text + "', " + txtDropoff1.Text + "', " + txtDropoff2.Text + "', " + txtDropoffpost.Text + "

应该是

insert into booking values('" + txtfirstname.Text + "', '" + txtSurname.Text + "', '" + txtAddressline1.Text + "', '" + txtAddressline2.Text + "', '" + txtPostcode.Text + "', " + txtTime.Text + "', '" + txtPeople.Text + "', '" + txtDropoff1.Text + "', '" + txtDropoff2.Text + "', '" + txtDropoffpost.Text + "')"

【讨论】：

请发布您的 web.xml 的部分
所以 Database.My.MySettings.Database1ConnectionString1 应该被替换为 DatabaseEntities 或 ConnectionString
这两种方法我都试过了，都不管用。这是我收到的错误“System.NullReferenceException：对象引用未设置为对象的实例。”

【解决方案3】：

您应该使用“项目设置”窗口中的连接字符串向导。然后尝试测试连接按钮，确保设置的类型是 ConnectionString 如果设置正确，您应该能够使用此语法获取连接字符串。

con.ConnectionString = my.Settings.Database1ConnectionString1

【讨论】：

【解决方案4】：

strSQL = "INSERT INTO user_account_details" & _
                "(lastname,firstname,middlename,usertype,reg_date_time,status)" & _
                " VALUES ( " & _
                " '" & txtLName.Text & "', " & _
                " '" & txtFName.Text & "' , " & _
                " '" & txtMName.Text & "' , " & _
                " '" & cboUserType.Text & "' , " & _
                " '#" & Now & "#', " & _
                " 'Inactive' " & _
                ")"

【讨论】：