在SQL中，您在数据库中的列类型应该是图像类型，您可以按照下面的代码进行参考和也用于更新去更新查询而不是插入：

In SQL your column type in database should be image type and you can follow below code for reference and also for update go for update query instead of Insert :

Protected Sub btnSubmit_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnSubmit.Click
        Dim connection As SqlConnection = Nothing
        Try
            Dim img As FileUpload = CType(imgUpload, FileUpload)
            Dim imgByte As Byte() = Nothing
            If img.HasFile AndAlso Not img.PostedFile Is Nothing Then
                'To create a PostedFile
                Dim File As HttpPostedFile = imgUpload.PostedFile
                'Create byte Array with file len
                imgByte = New Byte(File.ContentLength - 1) {}
                'force the control to load data in array
                File.InputStream.Read(imgByte, 0, File.ContentLength)
            End If
            ' Insert the employee name and image into db
            Dim conn As String = ConfigurationManager.ConnectionStrings("EmployeeConnString").ConnectionString
            connection = New SqlConnection(conn)
 
            connection.Open()
            Dim sql As String = "INSERT INTO EmpDetails(empname,empimg) VALUES(@enm, @eimg) SELECT @@IDENTITY"
            Dim cmd As SqlCommand = New SqlCommand(sql, connection)
            cmd.Parameters.AddWithValue("@enm", txtEName.Text.Trim())
            cmd.Parameters.AddWithValue("@eimg", imgByte)
            Dim id As Integer = Convert.ToInt32(cmd.ExecuteScalar())
            lblResult.Text = String.Format("Employee ID is {0}", id)
        Catch
            lblResult.Text = "There was an error"
        Finally
            connection.Close()
        End Try
    End Sub