SQLBase ODBC connection ASP.NET

[cs0307]

Hello,

we have developed a desktop application in SQLWindows that uses a SQLBase database to store and communicate with customer data. Now we are about to develop a web feature for this application. The user has the chance to connect to the same database via a website developed in ASP.NET.

Via ODBC I am connecting the ASP.NET (C#) website with the database. By inserting a name into a TextBox the user can search customers stored in the database. I can access the data and show all customers with similar names. But after 2, sometimes 3 or 4 SQL queries I get the following error window shown (starting the application out of visual web developer 2010):

_______________
Title: WebDev.WebServer40.exe
Message: WebDev.WebServer40.exe is not working properly anymore - The system is looking for a solution to solve the problem.
_______________

But there is no solution found.

When I copy the application to the web server I get the following error message (translated into english):

Server error in application:
The system tried to read or write into saved memory. Often this is an indication that other memory/storage is damaged.

Description: Unhandled exception during executing the actual web application. Check stack monitoring to get more information of the error.
Details: System.AccessViolationException: The system tried to read or write into saved memory. Often this is an indication that other memory/storage is damaged.

Source error:

Code: Select all

gv_GridView1.DataSource = cmd.ExecuteReader(CommandBehavior.CloseConnection);
[b]gv_GridView1.DataBind();[/b]
conODBC.Close();

Source file: c:\inetpub\wwwroot\search_using.aspx.cs Zeile: 40

Stack monitoring:

Code: Select all

[AccessViolationException: The system tried to read or write into saved memory. Often this is an indication that other memory/storage is damaged. ]
  System.Data.Common.UnsafeNativeMethods.SQLGetData(OdbcStatementHandle StatementHandle, UInt16 ColumnNumber, SQL_C TargetType, CNativeBuffer TargetValue, IntPtr BufferLength, IntPtr& StrLen_or_Ind) +0
  System.Data.Odbc.OdbcStatementHandle.GetData(Int32 index, SQL_C sqlctype, CNativeBuffer buffer, Int32 cb, IntPtr& cbActual) +30
  System.Data.Odbc.OdbcDataReader.GetData(Int32 i, SQL_C sqlctype, Int32 cb, Int32& cbActualOut) +89
  System.Data.Odbc.OdbcDataReader.internalGetString(Int32 i) +93
  System.Data.Odbc.OdbcDataReader.GetValue(Int32 i, TypeMap typemap) +72
  System.Data.Odbc.OdbcDataReader.GetValue(Int32 i) +57
  System.Data.Odbc.OdbcDataReader.GetValues(Object[] values) +62
  System.Data.Common.DbEnumerator.MoveNext() +69
  System.Web.UI.WebControls.GridView.CreateAutoGeneratedColumns(PagedDataSource dataSource) +284
  System.Web.UI.WebControls.GridView.CreateColumns(PagedDataSource dataSource, Boolean useDataSource) +418
  System.Web.UI.WebControls.GridView.CreateChildControls(IEnumerable dataSource, Boolean dataBinding) +640
  System.Web.UI.WebControls.CompositeDataBoundControl.PerformDataBinding(IEnumerable data) +57
  System.Web.UI.WebControls.GridView.PerformDataBinding(IEnumerable data) +14
  System.Web.UI.WebControls.DataBoundControl.OnDataSourceViewSelectCallback(IEnumerable data) +114
  System.Web.UI.DataSourceView.Select(DataSourceSelectArguments arguments, DataSourceViewSelectCallback callback) +31
  System.Web.UI.WebControls.DataBoundControl.PerformSelect() +142
  System.Web.UI.WebControls.BaseDataBoundControl.DataBind() +73
  System.Web.UI.WebControls.GridView.DataBind() +4
  search.search_button_OnClick(Object sender, EventArgs e) in c:\inetpub\wwwroot\search_using.aspx.cs:40
  System.Web.UI.WebControls.ImageButton.OnClick(ImageClickEventArgs e) +108
  System.Web.UI.WebControls.ImageButton.RaisePostBackEvent(String eventArgument) +118
  System.Web.UI.WebControls.ImageButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +10
  System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +13
  System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +36
  System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1565

I was posting this error into a ASP.NET developer forum. They suggested an error in the ODBC driver.

I am using the following ODBC driver (for SQLBase 11.5):
Unify SQLBase | Version: 11.05.03.6932 | Gupta Technologies | SQLBASEODBC.DLL | 22.02.2010

Here is my source code:

search_using.aspx.cs

Code: Select all

using System;
using System.Collections.Generic;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.Configuration;
using System.Data.Odbc;
using System.Data;

public partial class search : System.Web.UI.Page{

  string connectionString;
  OdbcConnection conODBC;

  protected void Page_Load(object sender, EventArgs e)

  {
  }

  protected void search_button_OnClick(object sender, EventArgs e)
  {
    connectionString = WebConfigurationManager.ConnectionStrings["SQLBaseODBC2"].ConnectionString;
    conODBC = new OdbcConnection(connectionString);

    try
    {
      string sql = "SELECT NAME, VORNAME FROM PREQUITY.KUNDE WHERE (NAME = 'Maierhuber')";
      OdbcCommand cmd = new OdbcCommand(sql, conODBC);
      conODBC.Open();
      l_lblInfo.Text = "Conn successful";
      gv_GridView1.DataSource = cmd.ExecuteReader(CommandBehavior.CloseConnection);
      gv_GridView1.DataBind();
    }

    catch (Exception err)
   {
      l_lblInfo.Text = "Error reading database. " + err.Message;
    }

    finally
    {
      conODBC.Close();
    }
  }
}

Connectionstring:

Code: Select all

<add name="SQLBaseODBC2" connectionString="Dsn=O_PREQ;db=PREQ;uid=sysadm;isolevel=RL;Min Pool Size=10"/>

search_using.aspx

Code: Select all

<asp:Content ID="Content1" ContentPlaceHolderID="MainWindow" Runat="Server">
  
  <div class="toolbar">
    
    <asp:ImageButton ID="toolbar_search" ImageUrl="~/Shared/Images/toolbar/pb_suchen.bmp" runat="server" OnClick="search_button_OnClick" />

    
  </div>

  <div class="firstRowPanel">
    

    <!-- Name -->
    <asp:Label ID="l_Name_desc" Text="Name" runat="server" />
    <asp:TextBox ID="tb_Name_field" Text="" runat="server" CssClass="firstRow" /><br />

  
  <div>
    <asp:Label id="l_lblInfo" Text="" runat="server" />
  </div>

  <div class="search_table">
  
  <asp:datagrid 
      id="dg_DataGrid1" 
      runat="server" 
      CssClass = "StandardTable"
      EnableViewState="False">
      
      <ItemStyle backcolor="white"></ItemStyle>

    </asp:datagrid>

    <asp:GridView ID="gv_GridView1" runat="server">
      
    </asp:GridView>
    </div>
</asp:Content>

I don't know why the web server is crashing after a few SQL queries. Do you have any idea?

Thanks in advance
Conny

[cs0307]

I changed my code to use OLEDB and the problem is gone. So something must be wrong with the ODBC interface or driver.

[RainerE]

Due to our experiences, native is most stable, next comes the OLEDB driver and the .NET data provider and ODBC driver are buggy.

Regards,
Rainer

[robertgalp]

Try this one.....Asp.Net Connection String

Robert