Novice with mobile apps

When i started with VB6 someone told me there is nothing better than application (desktop) development, web is just a fragment of what you can do with application development, then with a shift in technology i moved to web development I did some really good work but most of it was web applications and not websites. now with almost 7 years of web development experience, i feel like a novice when i comes to mobile apps and top that off  they differ based on platform OS, there is that pioneering technology call iPhone apps and then we have Android apps and of course there are those windows mobile apps, blackberry apps, and Nokia symbian apps....


my interests lie in Android and to some extent iPhone apps..... looking forward to exploring and understand the technology and frameworks....   i will update the blogs with tit-bits i learn over a period of time. 

Data Types in SQL Server 2008

I Read a great article on database journal lately about data types in 2008
, i am sharing some basic info.

Numeric data types 

An Integer is a counting number with no decimal point or fractional piece. All negative numbers, positive numbers, and zero are integers. SQL Server breaks integers into four sizes:

BigInt: -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807

Int: -2,147,483,648 to 2,147,483,648

SmallInt: -32,768 to 32,767

TinyInt: 0 to 255

Here as a part of software design you need to clear what to use in which cases, it may be a simple choice to pick the largest range, but looking deep you need to understand first Bigint uses double the space as int, and the other being the application consuming the database gets what it expects and there are not overflow errors.

for decimal value numbers, there are  Decimal, Numeric, Money, and SmallMoney. The types Decimal and Numeric are functionally the same thing. Meaning, they will work, calculate and behave identically, the only difference is in the mathematical definition and not in the way SQL Server utilizes them.

Money and SmallMoney are really Decimals with a fixed amount of four decimal places to the right. SmallMoney can be valued from - 214,748.3648 to 214,748.3647 while the range of Money is from -922,337,203,685,477.5808 to 922,337,203,685,477.5807. One of the reasons for using Money rather than a Decimal includes the display option of dollar signs and commas after three digits.

Strings  


Here we will discuss Char, VarChar, and Text. As most of you might me aware of difference between char and varchar, where when a char(50) and varchar(50) columns are defined, char takes up 50 Bytes in respective of size of content saved in the column where varchar is flexible and takes up bytes required to save the length of the content. 


Char must be used in case of where it is know or understood that length of the text would be fixed like a char(1) column would make much more sense in case of a Sex column where only M/F is expected to saved instead of varchar, where as something like name should be varchar. 


Varchar has a max limit of 8000, though a new introduction of Varchar(max) has made it more flexible as the size can be unlimited in this case, and the main benefit of this is that as in case of Text column string operations cannot be done, while here all the string operations can be handled easily. Also the thing to note here is that Varchar(max) is all set to replace text in the future versions of SQL server as Text is supported in 2008 only as a part of backward compatibility. 


I will adding more to this, hope you like it.... please Digg, Kick or share this if you like this.     

Resetting DNN passwords

Yesterday me and my team came across a strange problem, we had a client DNN deployment on our server for demo, and for long the client was not interested or was too busy and suddenly he needs the see the site the problem the original developer was not available and no one else know the host or admin password 


BIG PROBLEM.....


Luckily one of my team member were able to find a post with solution, i am re- posting the procedure.

CREATE procedure [dbo].[uap_ResetPassword]

@UserName NVarChar(255),

@NewPassword NVarChar(255)

as

begin

Declare @PasswordSalt NVarChar(128)

Declare @ApplicationID NVarChar(255)

Declare @ApplicationName NVarChar(255)

Set @ApplicationID = (SELECT [ApplicationID] FROM aspnet_Users WHERE UserName=@UserName)

Set @ApplicationName = (SELECT [ApplicationName] FROM aspnet_Applications WHERE ApplicationID=@ApplicationID)

Set @PasswordSalt = (SELECT PasswordSalt FROM aspnet_Membership WHERE UserID IN (SELECT UserID FROM aspnet_Users WHERE UserName=@UserName))

–select @ApplicationID, @ApplicationName

declare @RetVal as int

Exec @RetVal = dbo.aspnet_Membership_ResetPassword @ApplicationName, @UserName, @NewPassword, 10, 10, @PasswordSalt, -5

return @RetVal

end

Orignal post: http://www.devprise.com/2006/09/26/how-to-reset-a-dnn-password-at-the-database/


Thanks Tony...

SQL Server Database analysis scripts

While browsing the net my team came across couple of very good analytical scripts, i would like to share this with everyone. often there is a scenario where you wonder how to find out what script or procedure is consuming most memory or have the most reads, this help to identify the possible bottle necks in the website.

The query below is really useful

1) Following Query will return top 10 queries having maximum order by number of executions:

SELECT TOP 10 qt.TEXT AS 'SP Name',
qs.execution_count AS 'Execution Count',
qs.execution_count/DATEDIFF(Second, qs.creation_time, GETDATE()) AS 'Calls/Second',
qs.total_worker_time/qs.execution_count AS 'AvgWorkerTime',
qs.total_worker_time AS 'TotalWorkerTime',
qs.total_physical_reads AS 'PhysicalReads',
qs.creation_time 'CreationTime'
FROM sys.dm_exec_query_stats AS qs
CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) AS qt
WHERE qt.dbid = (
SELECT dbid
FROM sys.sysdatabases
WHERE name = 'DatabaseName')
ORDER BY qs.total_physical_reads DESC

Though this is not as useful as query one, but can be handy in case of really large databases, where you need to identify what table is consuming how much memory, and may be the the data in some tables is not all that relevant now and can be deleted conditionally, help improve the performance.

2) Query to check the size of each table:

EXEC sp_MSforeachtable @command1="EXEC sp_spaceused '?'"

One major point, you need admin/sa access to run these scripts

Look forward to your comments on the same