Ebooks

Hi Friends
Hope you all are doing well. This to inform you that, I have uploaded some E Books. Please check out following links.

For MVC
Link: https://sites.google.com/site/akshatsharma80/home/-net-3-0-3-5/downloads
Book: aspnetmvc-nerdinner_v1

For Silverlight
Link: https://sites.google.com/site/akshatsharma80/home/-net-3-0-3-5/downloads
Book: Microsoft.Silverlight.4.Business.Application.Development.Beginners.Guide

For SQL SERVER
Link: https://sites.google.com/site/akshatsharma80/home/sql-server/downloads
Book: ebook_SQL_2008_Query_Performance_Tuning_Distilled.pdf

For Interviews
Link: https://sites.google.com/site/akshatsharma80/home/nterview

For Application Architecture
Link: https://sites.google.com/site/akshatsharma80/home/-net-application-architecture/downloads
Book: Application Architecture Guide v2

Hope you all appreciate it.

Calling ASP.NET Validators form JavaScript

There are situations when we want to call Asp.net validatiors form JavaScript.

As I ran in to one of them as I was using “ICallbackEventHandler” in my page and dynamically creating matrix of text boxes, but as we know in callbacks, page is not posted back to server and in this situation validators not work at all. After lots of googling I found a mechanism of initiating validators to work at client end.
One more such situation is when we want to close a pop up window on button click using window.close(). But before closing the window using JavaScript, we want to validate the data written in the controls of the window.    
It possible to call Asp.net validators from JavaScript.
You may have validators like below on your page

<asp:TableCell>

    <asp:RequiredFieldValidator runat="server" ID="rfvWeight" ControlToValidate="txtWeight1"
    ErrorMessage="Please enter weight." ToolTip="Weight can't be empty."                      Display="Dynamic">*</asp:RequiredFieldValidator>
    <asp:RegularExpressionValidator ID="vldWeight"   ControlToValidate="txtWeight1" ErrorMessage="Please enter valid weight value" ToolTip="Please enter valid weight value" ValidationExpression="^[0-9]*\.?[0-9]+$"
    runat="server" Display="Dynamic">*</asp:RegularExpressionValidator>
    <asp:TextBox ID="txtWeight1" Width="50px" runat="server"></asp:TextBox>
</asp:TableCell>

Now we want to make sure that .net validators get fired up on “Submit” button click

All we have to do to fire up .net validators is to call “Page_ClientValidate()” function.  The following JavaScript code shows how “Page_ClientValidate()” function can be used before closing/Submitting  window.

function CallSrv() {

      if (Page_ClientValidate()) {
        //To Do
        }
}

If your page have more then 1 validation group then pass that group name to “Page_ClientValidate()”

Summarizing Data Using COMPUTE and COMPUTE BY

A COMPUTE BY clause allows you to see both detail and summary rows with one SELECT statement. You can calculate summary values for subgroups, or a summary value for the whole result set.

• The COMPUTE clause takes the following information:
• The optional BY keyword. This calculates the specified row aggregate on a per column basis.
• A row aggregate function name. This includes SUM, AVG, MIN, MAX, or COUNT.
• A column upon which to perform the row aggregate function.

The summary values generated by COMPUTE appear as separate result sets in the query results. The results of a query that include a COMPUTE clause are like a control-break report. This is a report whose summary values are controlled by the groupings, or breaks, that you specify. You can produce summary values for groups, and you can also calculate more than one aggregate function for the same group.

When COMPUTE is specified with the optional BY clause, there are two result sets for each group that qualifies for the SELECT:

Results Sets Generated by COMPUTE

The summary values generated by COMPUTE appear as separate result sets in the query results. The results of a query that include a COMPUTE clause are like a control-break report. This is a report whose summary values are controlled by the groupings, or breaks, that you specify. You can produce summary values for groups, and you can also calculate more than one aggregate function for the same group.
When COMPUTE is specified with the optional BY clause, there are two result sets for each group that qualifies for the SELECT:

• The first result set for each group has the set of detail rows that contain the select list information for that group.
• The second result set for each group has one row that contains the subtotals of the aggregate functions specified in the COMPUTE clause for that group.

When COMPUTE is specified without the optional BY clause, there are two result sets for the SELECT:

• The first result set for each group has all the detail rows that contain the select list information.
• The second result set has one row that contains the totals of the aggregate functions specified in the COMPUTE clause.

Examples

CREATE TABLE Classification (

    Classif_ID        integer  NOT NULL PRIMARY KEY,
    Classification    varchar(25))
GO

INSERT into Classification VALUES( 1,"Pop")

INSERT into Classification VALUES( 2,"Country")
INSERT into Classification VALUES( 3,"Alternative")
INSERT into Classification VALUES( 4,"Metal")

CREATE TABLE CD (

     CD_ID              integer  NOT NULL PRIMARY KEY,
     CD_Title           varchar(40),
     Composer_ID        integer  NOT NULL,
     Classif_ID         integer  NOT NULL,
     SalesPrice        money,
     AverageCost       money)
GO

INSERT into CD VALUES(2000,"John",100,1,16.99,6.99)

INSERT into CD VALUES(2001,"Chicago 16",107,1,14.99,5.99)
INSERT into CD VALUES(2002,"Chicago 17",107,1,14.99,5.99)
INSERT into CD VALUES(2003,"Chicago 18",107,1,14.99,5.99)
INSERT into CD VALUES(2004,"Greatest Hits",107,1,16.99,7.99)
INSERT into CD VALUES(2005,"Midnight",101,3,14.99,5.99)
INSERT into CD VALUES(2006,"Mode",115,3,14.99,5.99)
INSERT into CD VALUES(2007,"Ultra",115,3,15.99,5.99)
INSERT into CD VALUES(2008,"Mindcrime",102,4,14.99,5.99)
INSERT into CD VALUES(2009,"Empire",102,4,14.99,5.99)
INSERT into CD VALUES(2010,"Land",102,4,12.99,4.99)
INSERT into CD VALUES(2011,"Night",103,4,11.99,3.99)
INSERT into CD VALUES(2012,"Pyromania",103,4,14.99,5.99)
INSERT into CD VALUES(2013,"Hysteria",103,4,14.99,5.99)
INSERT into CD VALUES(2014,"Hits",103,4,13.99,4.99)
INSERT into CD VALUES(2015,"Hits 2",104,2,15.99,6.99)
INSERT into CD VALUES(2016,"Greatest",105,2,14.99,5.99)
INSERT into CD VALUES(2017,"Hits 3",106,1,13.99,5.99)
INSERT into CD VALUES(2018,"Deep",108,1,12.99,2.99)
INSERT into CD VALUES(2019,"Turning",109,1,14.99,5.99)
INSERT into CD VALUES(2020,"TheHits",109,1,16.99,7.99)
INSERT into CD VALUES(2021,"Cars",110,1,9.99,3.99)
INSERT into CD VALUES(2022,"Anthology",110,1,25.99,11.99)
INSERT into CD VALUES(2023,"City",110,1,14.99,5.99)
INSERT into CD VALUES(2024,"Rick",111,1,11.99,2.99)
INSERT into CD VALUES(2025,"Live",112,1,19.99,8.99)
INSERT into CD VALUES(2026,"Pat",113,1,16.99,6.99)
INSERT into CD VALUES(2027,"Big",114,1,14.99,5.99)
INSERT into CD VALUES(2028,"Hurting",114,1,11.99,3.99)
INSERT into CD VALUES(2029,"Vol 1",116,1,9.99,2.99)
INSERT into CD VALUES(2030,"Vol 2",116,1,9.99,2.99)
GO

With BY
SELECT CD.Classif_ID,Classification.Classification,
      CD.SalesPrice
FROM CD,Classification
WHERE CD.Classif_ID = Classification.Classif_ID
ORDER BY Classification.Classification
COMPUTE MIN(CD.SalesPrice) by Classification.Classification

Without BY

SELECT CD.Classif_ID,Classification.Classification,
      CD.SalesPrice
FROM CD,Classification
WHERE CD.Classif_ID = Classification.Classif_ID
ORDER BY Classification.Classification
COMPUTE MIN(CD.SalesPrice)

Comparing COMPUTE to GROUP BY
The following summarizes the differences between COMPUTE and GROUP BY:

• GROUP BY produces a single result set. There is one row for each group containing only the grouping columns and aggregate functions that show the subaggregate for that group. The select list can contain only the grouping columns and aggregate functions.
• COMPUTE produces multiple result sets. One kind of result set contains the detail rows for each group containing the expressions from the select list. The other type of result set contains the subaggregate for a group, or the total aggregate for the SELECT statement. The select list can contain expressions other than the grouping columns or aggregate functions. The aggregate functions are specified in the COMPUTE clause, not in the select list.

Download Article

Using Custom Validation ASP.net (Custom Validator)

<asp:TextBox ID="txtPostalCode" runat="server"/>

<asp:CustomValidator ID="cvPostalCode" runat="server" ControlToValidate="txtPostalCode"

ClientValidationFunction="ClientValidate" OnServerValidate="ServerValidate"

ValidationGroup="Save"

Display="Dynamic">*</asp:CustomValidator>

Add Following Javascript for client side validation

<script language="javascript" type="text/javascript">

 function ClientValidate(source, arguments) {
   var country = document.getElementById('<%= ddlCountry.ClientID%>').value;
   var postcode = arguments.Value;
   if (country == 'USNJ') {
     if ((postcode >= 07000 && postcode <= 07999) || (postcode >= 08500 && postcode <= 08999))
       arguments.IsValid = true;
     else {
       arguments.IsValid = false;
       source.errormessage = 'Please enter postal code in specified range of (07000-07999, 08500-08999).';
     }
}
else if (country == 'USNY') {
       if ((postcode >= 10000 && postcode <= 10399) || (postcode >= 10900 && postcode <= 11999))
          arguments.IsValid = true;
       else {
          arguments.IsValid = false;
          source.errormessage = 'Please enter postal code in specified range of (10000-10399, 10900-11999).';
       }
}
else {
     arguments.IsValid = true;
 }
}
</script>

As if in the case of clientside script fail to be executed we can create server function to handel such situation. Here is server code that will get executed if client side script will fail to be executed.

protected void ServerValidate(object source, ServerValidateEventArgs value)

{
  CustomValidator cv = (CustomValidator)source;
  string country = ddlCountry.SelectedValue;
  if (country == "USNJ")
  {
     if ((Convert.ToInt32(value.Value) >= 07000 && Convert.ToInt32(value.Value) <= 07999) || (Convert.ToInt32(value.Value) >= 08500 && Convert.ToInt32(value.Value) <= 08999))
            value.IsValid = true;
       else
       {
            value.IsValid = false;
            cv.ErrorMessage = "Please enter postal code in specified range of (07000-07999, 08500-08999).";
        }
  }
  else if (country == "USNY")
  {
       if ((Convert.ToInt32(value.Value) >= 10000 && Convert.ToInt32(value.Value) <= 10399) || (Convert.ToInt32(value.Value) >= 10900 && Convert.ToInt32(value.Value) <= 11999))
            value.IsValid = true;
       else
       {
            value.IsValid = false;
            cv.ErrorMessage = "Please enter postal code in specified range of (10000-10399, 10900-11999).";
       }
  }
  else
  {
       value.IsValid = true;
  }
}

You can code validation according to your business rules and set “IsValid” property to false if punched data is not valid and at last one more thing to do is on form submition (on sauve/update or submit).

protected void btnSubmit_Click(object sender, EventArgs e)

{
  if (Page.IsValid)
  {
       //Do save/Update
  }
  else
  {
      ltError.Text =”OOPS..Page is not valid”;
  }
}

Some important links to learn URL rewriting

Some important links to learn URL rewriting

http://msdn.microsoft.com/en-us/library/ms972974.aspx
http://www.codeproject.com/KB/aspnet/url_rewriting_routing.aspx
http://weblogs.asp.net/scottgu/archive/2007/02/26/tip-trick-url-rewriting-with-asp-net.aspx
http://peterkellner.net/2008/08/24/urlrewrite-with-aspnet-urlrewriter-wildcard-mapping-iis6-iis7/
http://learn.iis.net/page.aspx/496/iis-url-rewriting-and-aspnet-routing/

Download/Open files of any type from you web application

This example illustrates a simple technique to download files of any type from you web application to the client browser. In addition to setting the MIME types, the example shows how to force the Download File dialog that allows the user to either run or save the file, even if the file type would normally display in the browser's window.

protected void lnkDownloadSample_Click(object sender, EventArgs e)

{
   DownloadFile("SampleCSV/AddressBook.csv", true);
}

private void DownloadFile(string fname, bool forceDownload)

{
   string path = MapPath(fname);
   string name = Path.GetFileName(path);
   string ext = Path.GetExtension(path);
   string type = "";
   // set known types based on file extension 
   if (ext != null)
   {
      switch (ext.ToLower())
      {
          case ".htm":
          case ".html":
               type = "text/HTML";
               break;
          case ".txt":
               type = "text/plain";
               break;
          case ".doc":
          case ".rtf":
               type = "Application/msword";
               break;
          case ".csv":
          case ".xls":
               type = "Application/x-msexcel";
               break;
       }
     }
     if (forceDownload)
     {
         Response.AppendHeader("content-disposition",
                    "attachment; filename=" + name);
     }
     if (type != "")
         Response.ContentType = type;
     Response.WriteFile(path);
     Response.End();
     }
}

QUOTED_IDENTIFIER ON and ANSI_NULL ON?

If we create a Stored Procedure in Query Analyzer/ Management Studio, it is created with following SQL commands prefixed.
What are these – QUOTED_IDENTIFIER ON and ANSI_NULL ON?
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO

Answer from Tulika:

SET ANSI_NULLS
When SET ANSI_NULLS is ON, a SELECT statement that uses WHERE column_name = NULL returns zero rows even if there are null values in column_name. A SELECT statement that uses WHERE column_name <> NULL returns zero rows even if there are nonnull values in column_name.
When SET ANSI_NULLS is OFF, the Equals (=) and Not Equal To (<>) comparison operators do not follow the ISO standard. A SELECT statement that uses WHERE column_name = NULL returns the rows that have null values in column_name. A SELECT statement that uses WHERE column_name <> NULL returns the rows that have nonnull values in the column. Also, a SELECT statement that uses WHERE column_name <> XYZ_value returns all rows that are not XYZ_value and that are not NULL.
When SET ANSI_NULLS is ON, all comparisons against a null value evaluate to UNKNOWN. When SET ANSI_NULLS is OFF, comparisons of all data against a null value evaluate to TRUE if the data value is NULL.


Example:
set ansi_nulls on declare @myTab table (id int null, [name] varchar(10) null)
insert into @myTab (id,[name]) values (2, 'dave')
insert into @myTab (id,[name]) values (3, null)
select * from @myTab
select * from @myTab where [name] is null
select * from @myTab where [name] = null


SET QUOTED_IDENTIFIER
When SET QUOTED_IDENTIFIER is ON, identifiers can be delimited by double quotation marks, and literals must be delimited by single quotation marks. When SET QUOTED_IDENTIFIER is OFF, identifiers cannot be quoted and must follow all Transact-SQL rules for identifiers.
SET QUOTED_IDENTIFIER must be ON when you are creating or changing indexes on computed columns or indexed views. If SET QUOTED_IDENTIFIER is OFF, CREATE, UPDATE, INSERT, and DELETE statements on tables with indexes on computed columns or indexed views will fail. For more information about required SET option settings with indexed views and indexes on computed columns
When a table is created, the QUOTED IDENTIFIER option is always stored as ON in the table's metadata even if the option is set to OFF when the table is created.

Example:
SET QUOTED_IDENTIFIER OFF
GO
-- An attempt to create a table with a reserved keyword as a name
-- should fail.
CREATE TABLE "select" ("identity" INT IDENTITY NOT NULL, "order" INT NOT NULL);
GO
SET QUOTED_IDENTIFIER ON;
GO
-- Will succeed.
CREATE TABLE "select" ("identity" INT IDENTITY NOT NULL, "order" INT NOT NULL);
GO