Checks for a condition and displays a message if the condition is false.
Assert(Boolean) Checks for a condition and outputs the call stack if the condition is false.
Refer: http://msdn.microsoft.com/en-us/library/system.diagnostics.debug.assert.aspx

One advantage of Debug.Assert() is that the C# and VB compilers (not C++) eliminate the Debug.Assert() statement from the CIL code when the DEBUG precompile constant is not defined.
Refer: http://mark.michaelis.net/Blog/DontUseTheSystemDiagnosticsAssertMethodsUnless.aspx

Dont use it in production / release code.

When you want to export data, you can choose formats such as XML or csv for the data files. The XML format is more widely used for its flexibility and is desirable by many systems to be able to process the data. This article explains how to create xml files from C# classes.

Situation: Where would you use it:
- When you have to export data from one system to another system on a different platform
- When you have to setup scheduled jobs to export data
- When you want to keep a backup of key data on a regular basis. Though the database will give (better) alternatives, this technique will help you in shared hosting environments where you may want to keep a good backup of users who have signed up on your site, on a daily basis, for example.

This article touches the following technological aspects:
- C# class library
- Creating XML Schema (XSD)
- Generating C# Class file from XSD
- Generating XML files from C# object using XmlSerializer

Figure 1: Generate xml to export data

Example:
Suppose you have the following data which need to be exported in the form of XML files.
Customers:
CustomerID
CompanyName
ContactName
Address
City
PostalCode
Country
Phone
Fax

Each customer may have one-to-many Orders.

Orders:
OrderID
CustomerID
OrderDate
RequiredDate
ShippedDate
ShipAddress
ShipCity
ShipPostalCode
ShipCountry

To export this data on a daily basis, you would create XML files in the following format:

<Customers>
<CustomerID />
<CompanyName />
…
<Orders>
<OrderID />
<OrderDate />
…
</Orders>
<Orders />
<Orders />
…
</Customers>
<Customers />
<Customers />
…

Here are the steps to create it:

1) Create new project in Visual Studio

Figure: Creating New Project

2) Add a class library to the project

Figure: Adding a class library to the solution

3) Add a schema (.xsd) file to the class library project

Figure: Adding schema file to the project

4) Add schema elements. There are different ways in which you can add elements. One simple way is to drag and drop the database tables from the server explorer into the .xsd’s design area (when MySchema.xsd is opened with XML Schema Editor).

For this exercise, add Customers and Orders tables from the Northwind database from the server explorer.

The completed schema will look like this in the designer.

Figure: Customers and Orders schema

See the project source code to view the XSD code (ie with XML tags)

5) Generate the C# Class from xsd

At the VS Command prompt, enter xsd /c MySchema.xsd. This will create MySchema.cs. Rename it to MySchemaClass.cs, add it to the MyDataLayer class library project, update the namespace of MySchemaClass.cs

If your schema’s top element is named ExportData, (<xs:element name=“ExportData“>) MyDataLayer class will have a class named ExportData (public partial class ExportData).

(I’ve also updated the OrderDate datatype to be string in the generated class, to produce a formatted output in the XML)

6) Create the object from ExportData class and fill the object’s properties with data (from Database or from any other source).

eg:

private ExportData _exportXmlData = new ExportData();
(See the source code for full details).

7) Use the XmlSerializer to create XML files

eg:

FileStream fs = null;

try
{
XmlSerializer serializer = new XmlSerializer(typeof(ExportData));

fs = new FileStream(_fileName, FileMode.Create, FileAccess.Write);

serializer.Serialize(fs, _exportXmlData);

}

catch
{
throw;

}
finally

{

if (fs != null)
{
fs.Close();

}
}

(See the source code for full details).

8 ) Run the project. It will create the XML files containing data, which can be exported (via ftp or saved directly to a shared drive).

A typical customer data in the XML file produced by this example will have the following format:

<Customers>

<CustomerID>2</CustomerID>

<CompanyName>Company Name 2</CompanyName>

<ContactName>Contact Name 2</ContactName>

<City>Dallas 2</City>

<Orders>

<OrderID>2000</OrderID>

<OrderDate>Tuesday, August 19, 2008</OrderDate>

<RequiredDate>2008-08-21T14:33:31.8125-05:00</RequiredDate>

<ShipName>UPS 2</ShipName>

</Orders>

<Orders>

<OrderID>2001</OrderID>

<OrderDate>Tuesday, August 19, 2008</OrderDate>

<RequiredDate>2008-08-21T14:33:31.8125-05:00</RequiredDate>

<ShipName>UPS 2</ShipName>

</Orders>

</Customers>

Source Codes:

Please click here to get the source code link. (I hate spam as much as you do and your email id will never be given to others)

Feel free to comment your thoughts / questions / suggestions below.

A while ago, I wrote a small how-to on “Getting started with ASP.NET AJAX”. The article describes how to setup ASP.NET AJAX for the first time and then create a first application. Here’s a live demo: http://www.dataproxl.com/Demos/asp-net-ajax-enabled1.aspx and here’s the link to the full article: http://dataproxl.googlepages.com/gettingstartedwithasp.netajax

I’ve worked on few other samples afterwards, need to find time to post them.

If you have any of your ASP.NET AJAX demos and/or links, please add them to the comments.

Highlights:

- Dataset with 2 tables
- Custom paging on the Datalist
- Stored Procedure returns only the records needed for a page. This is useful when the table has thousands of rows
- Source code in both VB 2005 and C# 2005

Source Code Snippets: VB 2005, C# 2005, T-SQL, web.config

To see the demo, please go to: http://www.jotnow.net

VB 2005:

DataList:

<asp:Literal runat=”server” ID=”litMsg”></asp:Literal>
<asp:DataList runat=”server” ID=”dlStories” EnableViewState=”false”>

<ItemTemplate>

<div class=”storyTitle”><%#DataBinder.Eval(Container.DataItem, “Title”)%></div>
<div class=”storyBy”><b>By: </b><%#DataBinder.Eval(Container.DataItem, “SubmittedBy”)%></div>
<div class=”storyAudience”><b>Category: </b><%#DataBinder.Eval(Container.DataItem, “IntendedAudience”)%></div>
<div class=”storyDate”><b>Date Posted: </b><%#DataBinder.Eval(Container.DataItem, “DateSubmitted”)%> <i>GMT</i>   <span class=”viewed”><b>Viewed</b> <%#DataBinder.Eval(Container.DataItem, “NbrOfViews”)%> times</span></div>
<div class=”storyBodyHead”><b>Story/Jot: </b></div>
<div class=”storyBody”><%#Replace(DataBinder.Eval(Container.DataItem, “Story”), vbCrLf, “<br>”)%>…  <a href=’<%#DataBinder.Eval(Container.DataItem, “StoryId”, “full-Story.aspx?i={0}&Story=”)%><%#Server.UrlEncode(DataBinder.Eval(Container.DataItem, “TitleUrl”))%>’><b>Full Story</b></a></div>

<div class=”storySeperater”> </div>

</ItemTemplate>

</asp:DataList>

<div class=”pageNbrs”><asp:Literal runat=”server” ID=”litPageNbrs”></asp:Literal></div>

Populating the Datalist

Imports System
Imports System.Data
Imports System.Data.SqlClient

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
litMsg.Text = “”

If Not IsPostBack Then

Dim strCategory As String = “”
Dim strSearch As String = “”
Dim currentPage As Integer = 0
If Not IsNothing(Request.QueryString(“category”)) Then
If Request.QueryString(“category”).Trim.Length > 0 Then
strCategory = Server.UrlDecode(Request.QueryString(“category”).Trim)
litMsg.Text = “<span class=’msg’>Category = ” & strCategory & “<br /></span>”
End If
End If
If Not IsNothing(Request.QueryString(“search”)) Then
If Request.QueryString(“search”).Trim.Length > 0 Then
strSearch = Server.UrlDecode(Request.QueryString(“search”).Trim)
litMsg.Text &= “<span class=’msg’>Search Phrase = ” & strSearch & “<br /></span>”
End If
End If
If IsNumeric(Request.QueryString(“cp”)) Then
currentPage = Request.QueryString(“cp”).Trim
End If
If litMsg.Text.Trim.Length > 0 Then
litMsg.Text &= “<br />”
End If

Dim ds As DataSet
Dim cn As SqlConnection
Dim da As SqlDataAdapter

cn = New SqlConnection(System.Configuration.ConfigurationManager.AppSettings(“snjConnectionString”))
da = New SqlDataAdapter(“usp_get_Stories”, cn)
ds = New DataSet()

Try
With da.SelectCommand
.CommandType = CommandType.StoredProcedure

If strCategory <> “” AndAlso strCategory <> “All” Then
.Parameters.Add(New SqlParameter(“@Category”, SqlDbType.VarChar, 50))
.Parameters(“@Category”).Value = strCategory
End If

If strSearch <> “” Then
.Parameters.Add(New SqlParameter(“@Search”, SqlDbType.VarChar, 50))
.Parameters(“@Search”).Value = strSearch
End If

If currentPage <> 0 Then
.Parameters.Add(New SqlParameter(“@CurrentPage”, SqlDbType.Int))
.Parameters(“@CurrentPage”).Value = currentPage
End If

End With

da.Fill(ds)
If ds.Tables.Count > 0 Then
ds.Tables(0).TableName = “Stories”
ds.Tables(1).TableName = “Stats”
End If

If Not IsNothing(ds.Tables(“Stories”)) Then
dlStories.DataSource = ds.Tables(“Stories”).DefaultView
dlStories.DataBind()
End If

If ds.Tables(“Stats”).Rows.Count > 0 Then
Dim dtRow As DataRow = ds.Tables(“Stats”).Rows(0)
If Not IsDBNull(dtRow(“TotalJots”)) Then Session(“TotalJots”) = dtRow(“TotalJots”)
If Not IsDBNull(dtRow(“TotalViews”)) Then Session(“TotalViews”) = dtRow(“TotalViews”)
If Not IsDBNull(dtRow(“TotalDeleted”)) Then Session(“TotalDeleted”) = dtRow(“TotalDeleted”)
If Not IsDBNull(dtRow(“TotalPages”)) Then
PageList(dtRow(“TotalPages”), strCategory, strSearch, currentPage)
End If
End If

Catch ex As Exception
Response.Write(“<span class=’error’>There’s an unexpected error. Please try again.<br /></span>”)

Finally
cn.Close()
da.Dispose()
ds.Dispose()

End Try

End If

End Sub

Custom Paging:

Private Sub CustomPaging(ByVal pages As Integer, ByVal cat As String, ByVal srch As String, Optional ByVal currpage As Integer = 1)
Dim i As Integer
Dim pageBegin As Integer
Dim pageEnd As Integer
Dim pgNbrs As String = “Pages (” & String.Format(“{0:0,0}”, pages.ToString) & “):  ”
If currpage < 1 Then currpage = 1
pageBegin = currpage – 2
If pageBegin < 1 Then
pageBegin = 1
End If
pageEnd = pageBegin + 4
If pageEnd > pages Then
pageEnd = pages
End If
If pageEnd – pageBegin < 4 Then
pageBegin = pageBegin – (4 – (pageEnd – pageBegin))
End If
If pageBegin < 1 Then
pageBegin = 1
End If
If currpage > 1 Then
pgNbrs &= “<a href=’” & “Default.aspx?category=” & cat & “&cp=1&search=” & srch & “‘ title= ‘First Page’><<</a>   ”
pgNbrs &= “<a href=’” & “Default.aspx?category=” & cat & “&cp=” & CStr(currpage – 1) & “&search=” & srch & “‘ title=’Previous Page’><</a>  ”
End If
For i = pageBegin To pageEnd
If i <> currpage Then
pgNbrs &= “ <a href=’” & “Default.aspx?category=” & cat & “&cp=” & i & “&search=” & srch & “‘>” & i & “” & “</a> ”
Else
pgNbrs &= “ <span class=’selectedPage’> ” & i & “ </span> ”
End If
Next
If pageEnd > currpage Then
pgNbrs &= “  <a href=’” & “Default.aspx?category=” & cat & “&cp=” & CStr(currpage + 1) & “&search=” & srch & “‘ title=’Next Page’>></a>   ”
End If
If currpage <> pages And pages <> 0 Then
pgNbrs &= “<a href=’” & “Default.aspx?category=” & cat & “&cp=” & CStr(pages) & “&search=” & srch & “‘ title=’Last Page’>>></a>”
End If
litPageNbrs.Text = pgNbrs
End Sub

C# 2005:

DataList:

<asp:Literal runat=”server” ID=”litMsg”></asp:Literal>
<asp:DataList runat=”server” ID=”dlStories” EnableViewState=”false”>

<ItemTemplate>

<div class=”storyTitle”><%#DataBinder.Eval(Container.DataItem, “Title”)%></div>
<div class=”storyBy”><b>By: </b><%#DataBinder.Eval(Container.DataItem, “SubmittedBy”)%></div>
<div class=”storyAudience”><b>Category: </b><%#DataBinder.Eval(Container.DataItem, “IntendedAudience”)%></div>
<div class=”storyDate”><b>Date Posted: </b><%#DataBinder.Eval(Container.DataItem, “DateSubmitted”)%> <i>GMT</i>   <span class=”viewed”><b>Viewed</b> <%#DataBinder.Eval(Container.DataItem, “NbrOfViews”)%> times</span></div>
<div class=”storyBodyHead”><b>Story/Jot: </b></div>
<div class=”storyBody”><%#DataBinder.Eval(Container.DataItem, “Story”)%>…  <a href=’full-story.aspx?storyId=<%#DataBinder.Eval(Container.DataItem, “StoryId”)%>’><b>Full Story</b></a></div>

<div class=”storySeperater”> </div>

</ItemTemplate>

</asp:DataList>

<div class=”pageNbrs”><asp:Literal runat=”server” ID=”litPageNbrs”></asp:Literal></div>

Populating the Datalist

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

using System.Data.SqlClient;

public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
litMsg.Text = “”;

if (!IsPostBack)
{
string strCategory = “”;
string strSearch = “”;
int currentPage = 0;
if (Request.QueryString["category"] != null)
{
if (Request.QueryString["category"].Trim().Length > 0)
{
strCategory = Server.UrlDecode(Request.QueryString["category"].Trim());
litMsg.Text = “<span class=’msg’>Category = ” + strCategory + “<br /></span>”;
}
}
if (Request.QueryString["search"] != null)
{
if (Request.QueryString["search"].Trim().Length > 0)
{
strSearch = Server.UrlDecode(Request.QueryString["search"].Trim());
litMsg.Text += “<span class=’msg’>Search Phrase = ” + strSearch + “<br /></span>”;
}
}
int result;
if (int.TryParse(Request.QueryString["cp"], out result))
{
currentPage = int.Parse(Request.QueryString["cp"].Trim());
}
if (litMsg.Text.Trim().Length > 0)
{
litMsg.Text += “<br />”;
}

DataSet ds = null;
SqlConnection cn = null;
SqlDataAdapter da = null;

cn = new SqlConnection(System.Configuration.ConfigurationManager.AppSettings["snjConnectionString"]);
da = new SqlDataAdapter(“usp_get_Stories”, cn);
ds = new DataSet();

try
{
da.SelectCommand.CommandType = CommandType.StoredProcedure;

if (strCategory != “” && strCategory != “All”)
{
da.SelectCommand.Parameters.Add(new SqlParameter(“@Category”, SqlDbType.VarChar, 50));
da.SelectCommand.Parameters["@Category"].Value = strCategory;
}

if (strSearch != “”)
{
da.SelectCommand.Parameters.Add(new SqlParameter(“@Search”, SqlDbType.VarChar, 50));
da.SelectCommand.Parameters["@Search"].Value = strSearch;
}

if (currentPage != 0)
{
da.SelectCommand.Parameters.Add(new SqlParameter(“@CurrentPage”, SqlDbType.Int));
da.SelectCommand.Parameters["@CurrentPage"].Value = currentPage;
}

da.Fill(ds);
if (ds.Tables.Count > 0)
{
ds.Tables[0].TableName = “Stories”;
ds.Tables[1].TableName = “Stats”;
}

if (ds.Tables["Stories"] != null)
{
dlStories.DataSource = ds.Tables["Stories"].DefaultView;
dlStories.DataBind();
}

if (ds.Tables["Stats"].Rows.Count > 0)
{
DataRow dtRow = ds.Tables["Stats"].Rows[0];
if (!(System.Convert.IsDBNull(dtRow["TotalJots"])))
{
Session["TotalJots"] = dtRow["TotalJots"];
}
if (!(System.Convert.IsDBNull(dtRow["TotalViews"])))
{
Session["TotalViews"] = dtRow["TotalViews"];
}
if (!(System.Convert.IsDBNull(dtRow["TotalDeleted"])))
{
Session["TotalDeleted"] = dtRow["TotalDeleted"];
}
if (!(System.Convert.IsDBNull(dtRow["TotalPages"])))
{
int totPages;
//totPages = int.Parse(dtRow["TotalPages"].ToString);
totPages = (int)dtRow["TotalPages"];
CustomPaging(totPages, strCategory, strSearch, currentPage);
}
}

}
catch
{
Response.Write(“<span class=’error’>There’s an unexpected error. Please try again.<br /></span>”);

}
finally
{
cn.Close();
da.Dispose();
ds.Dispose();

}

}

}

Custom Paging:

private void CustomPaging(int pages, string cat, string srch)
{
CustomPaging(pages, cat, srch, 1);
}

private void CustomPaging(int pages, string cat, string srch, int currpage)
{
int i = 0;
int pageBegin = 0;
int pageEnd = 0;
string pgNbrs = “Pages (” + string.Format(“{0:0,0}”, pages.ToString()) + “):  ”;
if (currpage < 1)
{
currpage = 1;
}
pageBegin = currpage – 2;
if (pageBegin < 1)
{
pageBegin = 1;
}
pageEnd = pageBegin + 4;
if (pageEnd > pages)
{
pageEnd = pages;
}
if (pageEnd – pageBegin < 4)
{
pageBegin = pageBegin – (4 – (pageEnd – pageBegin));
}
if (pageBegin < 1)
{
pageBegin = 1;
}
if (currpage > 1)
{
pgNbrs += “<a href=’” + “Default.aspx?category=” + cat + “&cp=1&search=” + srch + “‘ title= ‘First Page’><<</a>   ”;
pgNbrs += “<a href=’” + “Default.aspx?category=” + cat + “&cp=” + System.Convert.ToString(currpage – 1) + “&search=” + srch + “‘ title=’Previous Page’><</a>  ”;
}
for (i = pageBegin; i <= pageEnd; i++)
{
if (i != currpage)
{
pgNbrs += “ <a href=’” + “Default.aspx?category=” + cat + “&cp=” + i + “&search=” + srch + “‘>” + i + “” + “</a> ”;
}
else
{
pgNbrs += “ <span class=’selectedPage’> ” + i + “ </span> ”;
}
}
if (pageEnd > currpage)
{
pgNbrs += “  <a href=’” + “Default.aspx?category=” + cat + “&cp=” + System.Convert.ToString(currpage + 1) + “&search=” + srch + “‘ title=’Next Page’>></a>   ”;
}
if (currpage != pages & pages != 0)
{
pgNbrs += “<a href=’” + “Default.aspx?category=” + cat + “&cp=” + System.Convert.ToString(pages) + “&search=” + srch + “‘ title=’Last Page’>>></a>”;
}
litPageNbrs.Text = pgNbrs;
}

}

Stored Procedure:

CREATE PROCEDURE dbo.usp_get_Stories
@Category varchar(50) = NULL,
@Search varchar(50) = NULL,
@CurrentPage int = NULL
AS
BEGIN

SET NOCOUNT ON;

declare @pageSize int
set @pageSize = 15

declare @totalJots numeric(18,0), @totalViews numeric(18,0), @totalDeleted numeric(18,0)
declare @avJots int, @totalPages int

/*========================================
“Stories”
=========================================*/
if @CurrentPage is null
set @CurrentPage = 1

select Identity(int,1,1) as thisId,
cast(StoryId as int) as StoryId, –’cos can’t insert another identity
Title,
TitleUrl = Replace(Replace(Replace(Replace(Replace(Title, ‘ ‘, ‘-’), ‘&’, ”), ‘,’, ”), ””, ”), ‘?’, ”),
SubmittedBy,
IntendedAudience,
Keywords,
Story = Replace(Replace(cast(Story as varchar(200)), ”, ”), ”, ”),
WebsiteName,
DateSubmitted = convert(varchar, DateSubmitted, 100),
NbrOfViews = isnull(NbrOfViews, 0)
into #stories
from Stories
where Cast(IsApprove as int) = 1 and isnull(IsDelete, 0) = 0
order by StoryId desc

if @Category is null and @Search is null
BEGIN
select @avJots = count(*) –@avJots = available jots for this search
from #stories

select top 15 *    –instead of using exec, 15 is hardcoded here
from #stories
where thisId > (@CurrentPage – 1) * @pageSize
order by thisId
END
else if @Category is not null and @Search is null
BEGIN

select @avJots = count(*)
from #stories
where IntendedAudience like ‘%’ + @Category + ‘%’

select top 15 *
from #stories
where thisId > (@CurrentPage – 1) * @pageSize
and IntendedAudience like ‘%’ + @Category + ‘%’
order by thisId
END
else if @Category is null and @Search is not null
BEGIN

select @avJots = count(*)
from #stories
where (Title like ‘%’ + @Search + ‘%’
or SubmittedBy like ‘%’ + @Search + ‘%’
or IntendedAudience like ‘%’ + @Search + ‘%’
or Keywords like ‘%’ + @Search + ‘%’
or Story like ‘%’ + @Search + ‘%’
or WebsiteName like ‘%’ + @Search + ‘%’
)

select top 15 *
from #stories
where thisId > (@CurrentPage – 1) * @pageSize
and (Title like ‘%’ + @Search + ‘%’
or SubmittedBy like ‘%’ + @Search + ‘%’
or IntendedAudience like ‘%’ + @Search + ‘%’
or Keywords like ‘%’ + @Search + ‘%’
or Story like ‘%’ + @Search + ‘%’
or WebsiteName like ‘%’ + @Search + ‘%’
)
order by thisId
END
else if @Category is not null and @Search is not null
BEGIN

select @avJots = count(*)
from #stories
where IntendedAudience like ‘%’ + @Category + ‘%’
and (Title like ‘%’ + @Search + ‘%’
or SubmittedBy like ‘%’ + @Search + ‘%’
or IntendedAudience like ‘%’ + @Search + ‘%’
or Keywords like ‘%’ + @Search + ‘%’
or Story like ‘%’ + @Search + ‘%’
or WebsiteName like ‘%’ + @Search + ‘%’
)

select top 15 *
from #stories
where thisId > (@CurrentPage – 1) * @pageSize
and IntendedAudience like ‘%’ + @Category + ‘%’
and (Title like ‘%’ + @Search + ‘%’
or SubmittedBy like ‘%’ + @Search + ‘%’
or IntendedAudience like ‘%’ + @Search + ‘%’
or Keywords like ‘%’ + @Search + ‘%’
or Story like ‘%’ + @Search + ‘%’
or WebsiteName like ‘%’ + @Search + ‘%’
)
order by thisId
END

/*========================================
“Stats”
==========================================*/
select @totalJots = count(*),
@totalViews = sum(isnull(NbrOfViews, 0))
from Stories
where Cast(IsApprove as int) = 1 and isnull(IsDelete, 0) = 0

select @totalDeleted = count(*)
from Stories
where isnull(IsDelete, 0) = 1

if @avJots % @pageSize = 0  –@avJots = available jots from above
set @totalPages = @avJots / @pageSize
else
set @totalPages = (@avJots / @pageSize) + 1

select TotalJots = @totalJots,
TotalViews = @totalViews,
TotalDeleted = @totalDeleted,
TotalPages = @totalPages

SET NOCOUNT OFF;

END

web.config:

<?xml version=”1.0″?>
<configuration>
<appSettings>
<add key=”snjConnectionString” value=”Data Source=(server name);Initial Catalog=(database name);Integrated Security=True;”/>
</appSettings>
<system.web>
…
…
</system.web>
…
…
</configuration>

To see the demo, please go to: http://www.jotnow.net