保存备注字段超过512个字符时会有问题

Question

我用vfpoledb.1驱动, 以OleDbCommand，OleDbCommandBuilder 等存取VFP数据库。保存输入的内容后，会发现备注字段中的内容有问题。
当备注的内容超过512个字符后，从第513个字符开始往后的内容并不是自己原本输入的内容，而是不断地重复第1至第512个字符的内容，而备注字段的长度与自己原本输入的内容长度一致，只是不断地重复第1至第512个字符的内容。我在本机的Win7+vs2010测试时是没有这个问题的，而在Server 2003+IIS6.0发布运行时会有以上的问题。
请各位大哥大姐指引解决这个问题，谢谢！

Answer 1

部分代码如下:
Imports System.Data.SqlClient
Imports System.Data
Imports System.Data.OleDb
Imports System.Web.Configuration
Public Class pds_list
    Inherits System.Web.UI.Page
    Public myDataTable As New DataTable
    Public myDataAdapter As New OleDbDataAdapter
    Dim cb2 As OleDbCommandBuilder
    Public sql_str As String = ""
    ............
    Protected Sub Button_save_Click(ByVal sender As Object, ByVal e As EventArgs) Handles Button_save.Click
sql_str = " select * from pds_hz where allt(pds_no)=='" + Label_pds_no.Text.ToString.ToUpper.Trim + "'"
Call Get_Data(sql_str, "myConnectionString", myDataTable, myDataAdapter)
            '   myDataTable.Rows(0).Item("pds_no") = Label_pds_no.Text
        myDataTable.Rows(0).Item("pds_name") = Textbox_edit_pds_name.Text.Trim
        .......
myDataTable.Rows(0).Item("pds_re") = TextBox_pds_re.Text.Trim  '备注字段的内容 Try
               cb2 = New OleDbCommandBuilder(myDataAdapter)
               myDataAdapter.Update(myDataTable)
               Label_message.Text = "The record has been updated successfully."
        Catch ex As Exception
               Label_message.Text = ex.Message
        End Try    End Sub.........    Public Function Get_Data(ByVal SQLstr As String, ByVal theConnectionString As String, ByVal OutputTable As DataTable, ByRef MyDataAdapter As OleDbDataAdapter)
        Dim conn_db As New OleDbConnection(WebConfigurationManager.ConnectionStrings(theConnectionString).ConnectionString.ToString())
        conn_db.Open()
        MyDataAdapter = New OleDbDataAdapter(SQLstr, conn_db)
        OutputTable.Clear()
        MyDataAdapter.Fill(OutputTable)
        conn_db.Close()
        Return OutputTable.Rows.Count
    End FunctionEnd Class

Answer 2

我试过好多次, 甚至测试改为
Dim x As String = "@@@###"
Dim y As String
y = New String("x", 2000)
myDataTable.Rows(0).Item("pds_re") = x + y得到的备注(pds_re)内容还是如下:
@@@###xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx@@@###xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx@@@###xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx@@@###xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Answer 3

原来也有外国人遇到这个问题, 但好象都没有解决方案.
http://social.msdn.microsoft.com/Forums/mr/visualfoxprogeneral/thread/cd4529e2-f727-40c3-8286-88c7fc1863b7
http://us.generation-nt.com/answer/vfp-memos-oledb-help-20856112.html
难道真是没有办法解决?

Answer 4

用VFP6.0重建数据库及数据表就正常了。