Bytes and Bites of Internet
Archive for October, 2010
ASP.NET and Page Not Found Error while debugging !
Oct 30th
Being sunny weekend today, with full of energy I began to work on making some prototype application which I have to present to my client sometimes during next week. It been a while since I worked on ASP.NET on my application (@ 2 weeks) since I installed Sharepoint Server 2010 demo in my machine. So, with having no idea of a monster under the bed, I made a simple web app and fired it up to debug … and with my little surprise, I got really weird “Page Not Found” error !!! To be honest, I have not seen this error before until today. And I had no idea that what went wrong with it. But I thought that may be it is because something is blocking up my access of application to web server. I checked with my new firewall software (Online Armor) which I had installed few weeks ago for testing purposes (yah, I love testing everything … 
) …
Access to SQL Server migration … and Compatibility Issues !!
Oct 7th
Recently I was involved in a migration project. Client was/is using ancient application built on Access 2.0 (yup … its 2.0) … I think it was started as a small app for just couple of users and with time it grew larger and soon it became mission critical application which still is built on old technology. Now here I am not gonna discuss about advantages of SQL Server over Access … because fact is both have their place in Data Processing Systems. In my native language we have a nice saying which loosely means that “sometimes we can’t do something by knife, that has to be done by needle” … having little bit interest in element of life and Zen … I consider myself self-proclaimed philosopher , ( if you have problem with that then … I really don’t care ) … oki back to discussion … what I meant to say is, in a situation where you need very small application that will be used by 1-2 or very few people, with very little data to process (v2.0,95,97 everyone had 1GB physical size limit), have very little or no budget, easy to maintain,deploy and design solution then I guess access is pretty good fit. But if there are high number of concurrent users (user > 5-10), high data storage capacity, requirement of better ( wayyy better ) security then SQL Server is ideal solution.
With that said, let me explain the situation that let me to write this blog post. I had already installed, patched and configured SQL Server properly on our database server, I had also prepared the workstation too, which was able to connect to database server. Now, I thought to try for test run of a sample migration. It was an access 97 file (which was originally access 2.0, converted to access 97 to be compatible with SQL Server import.) with just 2 database and had no other stuffs (or say views). I first opened that access file in my workstation to be sure that it is working (I mean not corrupted), after that I fired up SQL Server Migration Assistance (SSMA, is a great free utility by Microsoft which allows users to migrate access database to SQL Server, which can also be done by making package in SSIS).
And I was greeted with this message in SSMA console …
Starting conversion... Analyzing metadata... Access Object Collector error: Database Retrieving the COM class factory for component with CLSID {CD77B9-4FD-42C5-AE42-8D281F0419} failed due to the following error: 80040154. This error may be a result of running SSMA as 64-bit application while having only 32-bit connectivity components installed or vice versa. Please run SSMA in 32-bit (or 64-bit) mode or consider updating your connectivity components from http://go.microsoft.com/fwlink/?LinkId=197502. An error occurred while loading database information. Conversion finished with 0 errors, 0 warnings, and 0 informational messages. There is nothing to process.
SQL Server Views … gotcha while using sp_refreshview
Oct 6th
Last week I blogged about use of Views in SQL Server. We also saw different types of view and best practices for designing new view and limitations that may prevent us creating a view too. As a part of best practice while designing we should always include keyword, WITH SCHEMABINDING which prevents any accidental changes to base table on which we have defined the view.
Today’s post is about case when we have not use SCHEMABINDING with view, and in that case if we change underlying structure it will not appear in view till we use system stored procedure called SP_REFRESHVIEW. The syntax is something like this,
-- Sudo Code sp_refreshview [ @viewname= ] 'viewname'
Oracle 11g R2 and Windows 7 … dealing with Enterprise Manager Troubles
Oct 3rd
So, this weekend I thought to refresh my experience with Oracle. And in that attempt, I decided to install latest of Oracle DBMS family, Oracle 11g. Now, it’s been a while since I used oracle, it was version 10g. And they have been significantly improved in version 11g, so I wanted to try them. But I think something that have not changed or may be will never change is their web interface for EM (a.k.a. Enterprise Manager). If you have not used Oracle before then for info, EM is basically their central management console for installed Oracle instance.
Now if you are installing Oracle DBMS in a system which as “Static” IP (think of it as an IP that doesn’t change with time), then you have no problem at all. But if you are like me and installing in a machine which has DHCP enabled, and its IP gets changed frequently … or just say it is your laptop or desktop at home network, then you will not be able to access this EM after sometime. The reason is, It is sticked with your IP that it assumes is static !! So, you will get “Page Not Found” message when you will try to access EM, once your IP gets changed. And worse thing is in Oracle 10g, before installation the UI (Universal Installer) checks for pre-requisites and it warns you about having DHCP enabled but in Oracle 11g you will not see anything like that.
So, back to my experience. I installed Oracle 11g R2 as usual, and I fired up the EM. It worked just fine at first, but after sometime when I tried to run it again I was greeted with same old message “Page Not Found”. And I almost smashed my laptop 
(I know, sometimes I over react to things) … then I realized then I forgot the most important step of preparation, Installation of Microsoft Loopback Adapter !!
Installing Microsoft Loopback Adapter
Things look very different in Windows 7, so it was a bit difficult to find “ADD Hardware Wizard” to add an adapter. Then I found that I can run it using “hdwwiz.exe” and after that it is same as we used to with older windows versions. Following are screenshots of whole installation and configuration procedure.