Sql server 在datagridview中打开SQL Server MDF文件

我是VisualBasic新手，为了好玩，我上学期上了一堂VisualBasic课。我无法将datagridview连接到讲师给我的

.MDF

SQL Server数据库文件。我在sConnection.ConnectionString=“”上收到一个空异常错误，对此我感到不知所措

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    sConnection.ConnectionString = "Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Users\Jkome\Desktop\Kayaks.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True"
    sConnection.Open()

    sCommand.CommandText = "Select * from KayakTypes;"
    sReader = sCommand.ExecuteReader()
    sTable.Load(sReader)
    DGVkyaks.DataSource = sTable

试试这个

Imports System.Data.SqlClient
Public Class Form1
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim sTable As New DataTable
        Dim connectionString As String =
            <Text>
                Data Source=(LocalDB)\v11.0;
                AttachDbFilename=C:\Users\Jkome\Desktop\CustomerDatabase.mdf;
                Integrated Security=True;
                Connect Timeout=30
            </Text>.Value

        Using cn As New SqlConnection With {.ConnectionString = connectionString}
            Using cmd As New SqlCommand With
                {
                    .CommandText = "Select * from KayakTypes",
                    .Connection = cn
                }

                cn.Open()
                sTable.Load(cmd.ExecuteReader)

            End Using
        End Using

        DGVkyaks.DataSource = sTable

    End Sub
End Class

导入System.Data.SqlClient
公开课表格1
私有子按钮1\u单击（发送者作为对象，e作为事件参数）处理按钮1。单击
Dim稳定为新数据表
Dim connectionString作为字符串=
数据源=（LocalDB）\v11.0；
AttachDbFilename=C:\Users\Jkome\Desktop\CustomerDatabase.mdf；
综合安全=真实；
连接超时=30
价值
将cn用作具有{.ConnectionString=ConnectionString}的新SqlConnection
使用cmd作为新的SqlCommand
{
.CommandText=“从皮艇类型中选择*”，
.Connection=cn
}
cn.Open（）
sTable.Load（cmd.ExecuteReader）
终端使用
终端使用
DGVkyaks.DataSource=稳定
端接头
末级

首先，您的电脑上是否安装了默认设置（实例名为

SQLEXPRESS

）的SQL Server Express？