Changing Permission for Files and Folders

While working on ubuntu, some files and folders might not be accessible due to permission settings.
For example it is not possible to add/delete files or folders to /var/lib/mysql folder. But, this is one of the folders that one might one to visit with changes – like if you want to move the data files..
There is a tool in this regard:
1. Go to Applications->Accessories->Terminal
2. on the CLI, write sudo chmod OGE /folder/or/file/path
The first stands for owner, second for group, and third everyone. Each of these are going to be filled with numbers ranging from 1-7.
The permissions primarily include read, write and execute.
the most common for controlled usage is
sudo chmode 777 /folder/or/file/path
which means Owner can read write and execute and the same for Group and everyone
For recursive permission allocation
sudo chmode 777 -R /folder/or/file/path
For more visit https://help.ubuntu.com/community/FilePermissions

Server.Transfer() and Response.Redirect()

Working on my current project, I come up with a scenario to switch a visitor to a new page after some process.
Here I have an option to use either redirect() or server.transfer(). So what are the tradeoffs:

  • Redirect() would allow to navigate to other pages out of the current website unlike Transfer()
  • Redirect() needs a round-trip to client page but transfer() won’t need this which would make transfer() a bit fast

Well for my case, I am not redirecting to other page and I want it to be fast so – I have used Server.Transfer().

For questions related to page transfer refer http://msdn.microsoft.com/en-us/library/x3x8t37x.aspx

What is PostBack in ASP.NET

Postback in simple terms is self referal of the page. In earlier version of ASP, the form would ‘POST’ values to another page for validation or some process using the post method.
But in ASP.NET, the page which accepts the values through its form would be responsible for validating/processing the values.
More @ http://www.codersource.net/asp_net_post_back.html

How to add and drop primary key in SQL Server

If you want to add primary key after you create the table in the sql server, then
1. go to Microsoft SQL Server Management Studio
2. Right click on the database and select new query
3. ALTER TABLE tbl_name ADD PRIMARY KEY(pr_key_column);
tbl_name – name of the table you want to assign primary key
pr_key_column – column/field name which you want it to be primary key

If the pr_key_column is allowed null values, then you can’t assign it as primary key. So if that is the case use this query first:
ALTER TABLE tbl_name ALTER COLUMN pr_key_column datatype not null;

To revoke primary key:
ALTER TABLE tbl_name DROP CONSTRAINT(pr_key_column);

Previous releases of Microsoft Visual Studio 2008 failed error

While you are trying to install MS SQL Server 2008 on the machine which already has Visual studio, you might come up with this problem.

Here is the remedy.
Go to command prompt and move to the MS SQL Server installation DVD like:
C:…>E: – assuming your DVD drive letter is ‘E’
Then provide the following command:
SETUP /action=install /skiprules=vsshellinstalledrule
While you are installing, you might come up with error message but pass it selecting ok.

The other solution might be the trivial one – uninstall VS and install MS SQL Server then install VS – :-(
I hope it will help a lot.