Planning to Host WordPress Blog
Read this article..
http://www.gchandra.com/scripts/?p=172
Handling multiple configuration settings (Development, Staging, Production) gracefully.
In Asp.net 2.0 multiple connectionStrings & appSettings can be handled very easily using the attribute “configSource”
create a new xml file devAppSettings.config under a new folder myConfigsettings
How to Preserve Fileupload value in Asp.net ?
If you form has Fileupload control along with other controls like dropdownlist, calendar.. you will be facing standard problem of Fileupload control losing value when other controls are selected.
Click here to read the article in full…
Disable .pdb file generation in Release Mode
Visual Studio 2005 – Compile Options
In Visual Studio 2005, .pdb file gets generated in Debug mode and Release mode.
In debug mode it loads the entire symbol table, in Release mode it loads the key symbols.
In Release mode, the generated .pdb can be deleted very well deleted. (Because framework does not uses it)
To disable .pdb generation in Release mode, goto
Project Properties > Compile Tab > Advanced Compile Options
Goto Generate Debug Info (dropdown list) and select None.
SQL Server 2005 : Access Tables / Entities across Servers.
Accessing objects (tables..) across servers (SQL Server) is very simple.
Step 1: Create a link between two servers
Goto Query Window
EXEC sp_addlinkedserver 'PRODSVR', N'SQL Server' GO
‘PRODSVR’ is the name of the Server.Execute it.
Step 2: Setup Permission between Servers.In Management StudioGotoServer Object >> Linked Servers >>
PRODSVR (See Image)
Right Click on PRODSVR goto Properties and make changes as given below.
Step 3: To access the tables in other server
Use the following hirearchy
PRODSVR.dbname.dbo.tablename
To access Person.Address table from AdventureWorks database
Select * From PRODSVR.AdventureWorks.Person.Address
Advantages :
1. Update Production server with data from development server. (SSIS is alternate way)
2. Allow users to access production database without multiple logins. (windows authentication or SQL authentication)
SQL Server, Clean your Database Records and reset Identity Columns, The Shortest Path
(Copied from Moses’s Blog for my reference)
Well, I had a small issue regarding writing a script to clean a database we have and reset its identity columns in all tables. Although the database wasn’t huge one (less than 100 tables) I had to trace relations to be able to delete child table’s records before parent’s ones because of the foreign key constraints. The solution is disable the foreign keys and delete records with no fear of any errors then enables the constraints again.
Well, I found a solution to disable all constraints without the need to go on each table and disable it manually. and I was happy to know that I can use this solution in deleting all records from all tables. Not only this I was able to use the same solution to reset identity columns in all tables.
The solution was to use this built in stored procedure sp_MSforeachtable. For help about this proc search for it in Books online or use this sp_helptext sp_MSForeachtable.
Now back to my 6 lines, bellow is how I re-zeroed my Database:
1: /*Disable Constraints & Triggers*/
2: exec sp_MSforeachtable 'ALTER TABLE ? NOCHECK CONSTRAINT ALL'
3: exec sp_MSforeachtable 'ALTER TABLE ? DISABLE TRIGGER ALL'
4:
5: /*Perform delete operation on all table for cleanup*/
6: exec sp_MSforeachtable 'DELETE ?'
7:
8: /*Enable Constraints & Triggers again*/
9: exec sp_MSforeachtable 'ALTER TABLE ? CHECK CONSTRAINT ALL'
10: exec sp_MSforeachtable 'ALTER TABLE ? ENABLE TRIGGER ALL'
11:
12: /*Reset Identity on tables with identity column*/
13: exec sp_MSforeachtable 'IF OBJECTPROPERTY(OBJECT_ID(''?''), ''TableHasIdentity'') = 1 BEGIN DBCC CHECKIDENT (''?'',RESEED,0) END'
Organize your SQL Server 2005 tables in a better way !!
When you create tables in SQLServer (2005) by default its all get created under default schema. (dbo.)
If you have too many tables then the table list could be confusing / clumsy.
Here enters Schema
(see image)
To organize your tables into meaningful groups (or namespaces)
First create a schema
CREATE SCHEMA Person
GO
Then Alter your existing table
ALTER SCHEMA Lookup
TRANSFER dbo.Contact
GO
So now that you have grouped your tables into different schemas.
How to use them ? The usual way but with schema name added to it.
SELECT * FROM Person.Contact
What is Schema ? (from MSDN)Beginning in SQL Server 2005, each object belongs to a database schema. A database schema is a distinct namespace that is separate from a
database user. Schemas can be created and altered in a database, and users can be granted access to a schema. A schema can be owned by any
user, and schema ownership is transferable.
In previous versions of SQL Server, database users and schemas were conceptually the same object. Beginning in SQL Server 2005, users and schemas
are separate, and schemas serve as containers of objects.
AJAX – Export to Excel / Word
If you are using Update Panel and try to Export gridview contents to EXCEL or Word, your asp.net page will throw nasty error. “Sys.WebForms.PageRequestManagerParserErrorException”
Its because AJAX & Response.write don’t go together. By calling Response.Write() directly you are bypassing the normal rendering mechanism of ASP.NET controls. The bits you write are going straight out to the client without further processing (well, mostly…). This means that UpdatePanel can’t encode the data in its special format.
There are couple of ways to solve this problem.
1. Place the Export Button outside of Update Panel.
2. By Pass the Export Button using <Triggers>
</ContentTemplate>
<Triggers>
<asp:PostBackTrigger ControlID=”cmdExport” />
</Triggers>
</asp:UpdatePanel>
if your Export button is part of UserControl then specify usercontrolid:buttonid
</ContentTemplate>
<Triggers>
<asp:PostBackTrigger ControlID=”uscSelCtl:cmdExport” />
</Triggers>
</asp:UpdatePanel>
Asp.net Web Service Timing Out (0x80004005)
Recently if your webservices started failing / timing out it its worth your time to take a look at this support article.
“HttpException (0x80004005): Request timed out.”
“System.InvalidOperationException: There were not enough free threads in the ThreadPool object to complete the operation”
Contention, poor performance, and deadlocks when you make Web service requests from ASP.NET applications
http://support.microsoft.com/kb/821268
Related Reading :
Item 5 talks about Asp.Net WS
Asp.Net Filter Datatable by Column
Filter Datatable by Rows
If you need to get subset of a big dataset into datatable Rowwise …
Dim dtEmp as DataTable Dim dsEmployee as New DataSet dsEmployee = someobject.getdata() 'dataset can be populated in many ways which is not explained here. Dim sExpr as String Dim drRows() as DataRow, drSingleRow as DataRow sExpr = "EmpID > 100" 'Condition drRows = dsEmployee.Tables(0).Select(sExpr) 'If you need to add Sort Order it can be added to sExpr Dim sSortOrder as String sSortOrder = "EmpName DESC" drRows = dsEmployee.Tables(0).Select(sExpr,sSortOrder) For Each drSingleRow in drRows dtEmp.ImportRow(drRows) Next ' Datatable dtEmp has filtered records
Filter Datatable by Column
If you need to get subset of big dataset into datatable columnwise…
Dim dtEmp as DataTable
Dim dsEmployee as New DataSet
dsEmployoee = someobject.getdata() 'dataset can be populated in many ways which is not explained here.
'This copies the structure and data
dtEmp = dsEmployee.Tables(0).Copy
dtEmp.Columns.Remove("Unwanted Column 1")
dtEmp.Columns.Remove("Unwanted Column 2")
dtEmp.Columns.Remove("Unwanted Column 3")
SQL Server 2005 : Verify table already exists
Verifying that an object exists
If the table exists, it is deleted. If the table does not exist, the DROP TABLE statement is not executed.
IF OBJECT_ID (N’dbo.AWBuildVersion’, N’U’) IS NOT NULL
DROP TABLE dbo.AWBuildVersion;
GO
Syntax :
OBJECT_ID (‘object_name’, [‘object_type’])
Object Type is optional, and possible values it can hold are.. (Items in bold are frequently used)
Object type:
AF = Aggregate function (CLR)
C = CHECK constraint
D = DEFAULT (constraint or stand-alone)
F = FOREIGN KEY constraint
PK = PRIMARY KEY constraint
P = SQL stored procedure
PC = Assembly (CLR) stored procedure
FN = SQL scalar function
FS = Assembly (CLR) scalar function
FT = Assembly (CLR) table-valued function
R = Rule (old-style, stand-alone)
RF = Replication-filter-procedure
SN = Synonym
SQ = Service queue
TA = Assembly (CLR) DML trigger
TR = SQL DML trigger
IF = SQL inlined table-valued function
TF = SQL table-valued-function
U = Table (user-defined)
UQ = UNIQUE constraint
V = View
X = Extended stored procedure
IT = Internal table
Prevent Session Timeout in Asp.net
Prevent Session Timeout in Asp.net [VB]
ASP.Net 2.0 [VB]
Inspired by this article from Code Project. [Thanks Ach1lles ]
I slightly modified few things to work for VB and VS2005 environment. The code works perfect and I’m very happy with it.First I created a Module file and created this function.
Public Function KeepAlive() As String
Dim int_MilliSecondsTimeOut As Integer = (HttpContext.Current.Session.Timeout * 60000) - 30000
Dim sScript As New StringBuilder
sScript.Append("<script type='text/javascript'>" & vbNewLine)
'Number Of Reconnects
sScript.Append("var count=0;" & vbNewLine)
'Maximum reconnects Setting
sScript.Append("var max = 6;" & vbNewLine)
sScript.Append("function Reconnect(){" & vbNewLine)
sScript.Append("count++;" & vbNewLine)
sScript.Append("var d = new Date();" & vbNewLine)
sScript.Append("var curr_hour = d.getHours();" & vbNewLine)
sScript.Append("var curr_min = d.getMinutes();" & vbNewLine)
sScript.Append("if (count < max){" & vbNewLine)
sScript.Append("window.status = 'Refreshed ' + count.toString() + ' time(s) [' + curr_hour + ':' + curr_min + ']';" & vbNewLine)
sScript.Append("var img = new Image(1,1);" & vbNewLine)
sScript.Append("img.src = 'http://localhost/myapp/reconnect.aspx';" & vbNewLine)
sScript.Append("}" & vbNewLine)
sScript.Append("}" & vbNewLine)
sScript.Append("window.setInterval('Reconnect()',")
sScript.Append(int_MilliSecondsTimeOut.ToString() & "); //Set to length required" & vbNewLine)
sScript.Append("</script>")
KeepAlive = sScript.ToString
End Function
All this code does is, build a simple javascript function and its called from server side.The works like this,- Gets the current session timeout duration.
– Subtract 30 seconds from it and assign it to MilliSecondsTimeOut variable
– Create a Reconnect() javascript function
– Create a global variable with max value 6
– Get current hour and Min [just for displaying the last refresh time]
– Verify whether count is less than max value (ie 6)
– If so, change the window status with Text
– Create a dummy image and set reconnect.aspx url as its source [this way a call is made to server and it wont session timeout]Create a timer using window.setInterval and assign the MilliSecondsTimeOut value.
[this way this function is called 30 seconds before session timeout]Tha max value (6) can be set to any number. If its 6 then this session timeout is avoided 5 times.
Default session timeout is 20min. 20 * 5 = 100 mins. Which is good for non-secure page.
Then
On the pages where I want to prevent Session Timeout I entered this line.
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load Try 'dont forget to add this line Page.ClientScript.RegisterClientScriptBlock(Me.GetType, "reconn key", KeepAlive()) If Not Page.IsPostBack Then --- --- --- End If Catch eX as Exception '---- End Try End Sub
Created reconnect.aspx in Visual Studio and deleted the .vb and .designer.vb files.This is the final version of reconnect.aspx
<%@ Page Language="vb" AutoEventWireup="false"%> <%@ OutputCache Location="None" VaryByParam="None" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "<a href="http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd" mce_href="http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd</a>"> <html xmlns="<a href="http://www.w3.org/1999/xhtml" mce_href="http://www.w3.org/1999/xhtml">http://www.w3.org/1999/xhtml</a>" > </html>
Note : When you compile the project sometimes, VS2005 complains reconnect.aspx is not in right format.
So I EXCLUDED this file from my project. Now VS 2005 will compile without complaining and the logic will also work.- Happy Programming
Copy Datatable from one Dataset to another Dataset
Copying a datatable from one dataset to another was not that straightforward as I thought.
Dim dsSource As New DataSet Dim dsDestination As New DataSet 'Your way to get data from XML or DB. dsSource = object.getdata() dsDestination = object.getmoredata() 'This is important, without this it will result in error 'when you try to copy the datatable from one dataset to another dsSource.Tables(0).TableName = "NewTableName" dsDestination.Tables.Add(dsSource.Tables(0).Copy) dsDestination.Tables(0).Tablename = "SomeTable" dsDestination.Tables(1).Tablename = "NewTableName" 'The one we copied from other Dataset
Note 1 : When you are using more than one datatable in a dataset it is advisable you name the datatables.
Note 2 : These kinds of scenarios arise, when you are trying to establish Relation between datatables in a dataset.
(Cascading master – detail relation)
Creating dynamic, fancy EmptyDataText for GridView
Gridview has capability to display “default” messages when “No data” exists during binding.
Standard Way in .aspx
<asp:GridView ID=”gvControl” runat=”server” AutoGenerateColumns=”False” GridLines=”None” CellPadding=”0″ CellSpacing=”0″ OnRowDataBound=”gvCategories_RowDataBound” BackColor=”#dddddd” ShowHeader=”false” EmptyDataText=”<BR> No data exists <BR><BR>“>
….
…..
</asp:GridView>
Fancy Way (.vb or .cs)
You can make it fancy & dynamic by doing it in code behind.
Create fancy texts using WordArt (MS Word) and copy it to Image Editor (Paint.net, gimp, Paint) and save it as JPG.
gvControl.EmptyDataText = "<img src='~/images/NoData.jpg' border='0'>" gvControl.EmptyDataRowStyle.HorizontalAlign = HorizontalAlign.Center gvControl.databind
Note: When you use emptydatatext in codebehind donot forget to use databind.
‘The invoked member is not supported in a dynamic module.’
Error ‘The invoked member is not supported in a dynamic module.’ while generating exception string
While Using ASPUnhandledException.dll for exception handling, I received this error via email.
This error message was not at all helpful in production environment.
On careful debugging I found out that my Stored Proc failed.
Instead of giving the reason for Stored Proc failure it gave this obscure message. If someone knows why it gives this message it will be helpful.
(reason my sp failed was because I was calling a non-existing user defined function)
How to add Company & Version details to your Assembly file or .dll ?
If you want to add details like (Your [company] name, Product name, Copyright info, Version Number) to your custom library ?
ex :
Its very simple.
Open Assembly.vb or Assembly.cs and modify the following items.
You can add more attributes that are not given here. Use Visual Studio intelli-sense to find more attributes.
[VB]
<Assembly: AssemblyTitle(“Your Library Name”)>
<Assembly: AssemblyDescription(“Description about the library”)>
<Assembly: AssemblyCompany(“Your Company name”)>
<Assembly: AssemblyProduct(“Product Name”)>
<Assembly: AssemblyCopyright(“Copyright © 2007”)>
<Assembly: AssemblyTrademark(“Product Trademark”)>
<Assembly: ComVisible(False)>
<Assembly: AssemblyVersion(“1.0.0.0”)>
<Assembly: AssemblyFileVersion(“1.0.0.0”)>
Validation (XHTML 1.0 Transitional): A newer construct is recommended.
Validation (XHTML 1.0 Transitional): Attribute ‘name’ is considered outdated. A newer construct is recommended.
Deprecated Elements & Attributes and Newer Constructs
XHTML 1.0 Transitional
Elements |
Newer Constructs |
| <menu /> | Use another list type. |
| <u /> | Use CSS property “text-decoration” and set its value to “underline”. |
| <s /> | Use CSS property “text-decoration” and set its value to “line-through”. |
| <strike /> | Use CSS property “text-decoration” and set its value to “line-through”. |
| <basefont /> | Use CSS styling and set the “font-family” property to desired font. |
| <font /> | Use CSS styling to set the property of the element, such as a DIV or SPAN.The CSS properties include:
|
| <applet /> | Use the <object /> tag |
| <isindex /> | Use the <input /> tag |
| <i /> | Use the <em /> tag |
| <b /> | Use the <strong /> tag |
Elements / Attributes |
Newer Constructs |
| Iframe | |
| name | Use the ID attribute |
| align | Use the CSS property “text-align” |
| body | |
| background | Use the CSS property “background-image” or “background”. |
| bgcolor | Use the CSS property “background-color” or “background”. |
| text | Use the CSS property “color” for the “body” style |
| link | Use the CSS section “a:link” and set the property “color”. |
| vlink | Use the CSS section “a:visited” and set the property “color”. |
| alink | “a:hover” and set the property “color”. |
| div / p / h1…h6 | |
| align | Use the CSS property “text-align”. |
| ul / ol / li | |
| type | Use the CSS property “list-style-type” or “list-style”. |
| compact | This attribute has been removed from the HTML DOM 1.0 |
| hr | |
| align | Use the CSS property “text-align”. |
| noshade | Use the CSS property “color”. |
| size | Use the CSS property “height”. |
| width | Use the CSS property “width”. |
| pre | |
| width | Use the CSS property “width”. |
| name | Use the attribute “id”. |
| br | |
| clear | Use the CSS property “clear”. |
| object | |
| align | Use the CSS property “vertical-align” and “text-align” in the parent tag |
| border | Use the CSS property “border”. |
| hspace | Use the CSS property “padding”. |
| vspace | Use the CSS property “padding”. |
| img | |
| name | Use the attribute “id”. |
| align | Use the CSS property “vertical-align” and “text-align” in the parent tag |
| border | Use the CSS property “border”. |
| hspace | Use the CSS property “padding”. |
| vspace | Use the CSS property “padding”. |
| map | |
| name | Use the attribute “id”. |
| input | |
| align | Use the CSS property “vertical-align” and “text-align” |
| legend | |
| name | Use the attribute “id”. |
| table | |
| align | Set table’s CSS properties left-margin and right-margin at “auto” for centering, or right-margin to 0 for right alignment, or the left-margin to 0 for left alignment. |
| bgcolor | Use the CSS property “background-color”. |
| tr | |
| bgcolor | Use the CSS property “background-color”. |
| td, th | |
| nowrap | Use the CSS property “word-wrap”. |
| bgcolor | Use the CSS property “background-color”. |
| width | Use the CSS property “width”. |
| height | Use the CSS property “height”. |
PDF copy of the same is attached for download.
How strong User ID and Password should be ?
Few thoughts on how to enforce strong userids and passwords.
UserIDs can be email address. (An email can be sent to the ID with a link to make sure email id is valid)
– Password must be between 8 and 14 characters.
– Password must contain at least one number, at least one English uppercase character, and at least one English lowercase character.
– Password must contain one special character like #,*,&
– Password may not have more than two consecutive identical characters.
Ex : This is valid : grEen12# but grEEEn12# is not valid
– Password cannot be the same as your previous three passwords.
– Password cannot be similar as your previous three passwords.
Ex : If this is your old password grEen12#, new Password cannot be grEen13#
– Password cannot be the same as or contain your User ID or contain the word “password” or contain your site / company name.
Ex : If your site is abcjewellers then password cannot be aBcJewellers#1 or paSSword$1
– Password should expire every 60 days.
Script(s) 
