Roy Osherove TDD Masterclass

Roy Osherove is giving an hands-on TDD Masterclass in the UK, September 21-25. Roy is author of "The Art of Unit Testing" (http://www.artofunittesting.com/), a leading tdd & unit testing book; he maintains a blog at http://iserializable.com (which amoung other things has critiqued tests written by Microsoft for asp.net MVC - check out the testreviews category) and has recently been on the Scott Hanselman podcast (http://bit.ly/psgYO) where he educated Scott on best practices in Unit Testing techniques. For a further insight into Roy's style, be sure to also check out Roy's talk at the recent Norwegian Developer's Conference (http://bit.ly/NuJVa).

Full Details here: http://bbits.co.uk/tddmasterclass

bbits are holding a raffle for a free ticket for the event. To be eligible to win the ticket (worth £2395!) you MUST paste this text, including all links, into your blog and email Ian@bbits.co.ukwith the url to the blog entry. The draw will be made on September 1st and the winner informed by email and on bbits.co.uk/blog

Encode column values as xml in sql server 2005

The problem:

I needed to select rows from a database which corresponded to a note on a case. Each row was then written as xml to a file. Some of the columns in the row contained user entered information which could contain special characters which would create badly formed xml '<' and '>' for example. I needed a way to encode the column values when selected so that special characters were replaced.

The solution:

With a little help from the fellas over at StackOverflow.com I implemented a user-defined function which encoded the original column value. Performance wasn't a big concern as the query only ever returns one row, hence using a function;

ALTER FUNCTION [pega].[encodeTextForXml]
(
@string_to_encode varchar(1000)
)
RETURNS VARCHAR(MAX)

AS

BEGIN

declare @x xml

declare @encStr varchar(8000)

set @x = '<a/>'

set @x.modify('insert text{sql:variable("@string_to_encode")} as first into (/a)[1]')

set @encStr = CAST(@x.query('/a/text()') as varchar(8000))

RETURN @encStr

END

If I had the luxury of not being penned in by existing code, this would have been solved differently as suggested in the StackOverflow post, however it works well and does what it says on the tin!

Continual learning & getting involved

The Dean's speech at my graduation ceremony professed that this would not be the end of my learning, but in fact the beginning. Learning is a lifelong process. It was an interesting speech and one that has rung very true in my career as a developer. If you are not continually learning then you will quickly become stale as a developer, not only in terms of the code you are writing, but the tools and processes you are using to write it.

Since starting as a junior developer I have had a bit of an infiriority complex wher it comes to other developers. So after seeing a post by Jeremy Miller on CodeBetter I was inspired to do more than the odd hour of book reading that I had previously been kidding myself was enough to improve as a developer.

As part of my quest to become a better developer I have done the following;

Begun blogging - if you're reading this, you'll know all about it.
Started an out-of-work-hours side project
Attended community developer days (see below)
Begun contributing to StackOverflow
Subscribed to number of podcasts other than just Hansleminutes
Begun investigating MS Certification - Longer term goal.

Community events

One of the most productive things I have done recently to learn more is attend DDD SouthWest a free community developer event. It was an excellent event, not only in terms of the content of the presentations, but also the organisation of the day. Combine this with the fact that it was all free - even the delicious food - and its difficult to understand why there were any empty seats - ok it was on a Saturday!

The sessions I attended were;

Embracing a new world – dynamic languages and .Net - Ben Hall
Get Going With jQuery - George Adamson
Real-world MVC architecture - Steve Sanderson
What’s New In C# 4? - Guy Smith-Ferrier

Here is the full agenda which gives a brief overview of all the sessions that ran on the day as well as source code and slides.

During lunch there were a series of grok talks. Grok talks are 10 minute micro-presentations on a particular subject. Two of the ones that stuck with me were;

10 tips for speeding up sql server by Jon Reade (SqlServerClub.com)
A talk on the fututre of developing .net for mobile devices (A developer whos name escapes me)

I have been inspired to get ore involved in my local community developer events. There are lots of good ones in the Bristol / Bath area on whose mailing lists I have lurked for the past few years / months. Its time to de-lurk and get involved. Here are a few of the groups I plan to infiltrate over the coming months.

BathCamp
The .NET Developer Network
Underscore

Sql Server - Get most recent item from a table using sub-select

Recently I needed to create a kinda complex sql query to get the most recent note that had been added to a case in an internal application at work. This is something I come across infrequently enough to forget it every time I want to do it so I thought I would post it as it may be of some use to others (and me next time I need it!)

The requirement:
We need to get the latest case note entry made by a user not the system. Data required is date, time, user ID, subject and content fields.

The database structure:

Case Table

Column name	Type
Id (PK)	int

Note table

Column name	Type
Id (PK)	int
CreateDateTime	datetime
CaseId (FK)	varchar(50)
CreateOperator	varchar(50)
NoteTitle	varchar(100)
NoteContent	text
Service	varchar(50)

Service Table

Column name	Type
Id (PK)	int
CaseId (FK)	varchar(50)
Status	varchar(100)

The solution
It appears fairly straightforward at first glance. Just join across the three tables using primary keys and foreign keys. The complication comes in that we only want to see the most recently added note on a case.

So, I used a sub-select to get the most recently created note ( max(CreateDateTime) ) and compare it to the CreateDateTime in the original select statement. It’s probably easier to look at the sql……

DECLARE @Service varchar(20)
SET @Service = ‘MyServiceName’

SELECT attach.Service, attach.CreateDateTime, attach.pxLinkedRefFrom, work.Id, attach.NoteTitle, attach.NoteContent, idx.Status
FROM myCaseTable work
JOIN myNoteTable attach ON work.Id = attach.CaseId
LEFT OUTER JOIN myServiceTable idx ON idx.CaseId = attach.CaseId
WHERE attach.CreateDateTime =
(

SELECT MAX(CreateDateTime) FROM myNoteTable attach2
WHERE attach2.CaseId = attach.CaseId
AND attach2.CreateOperator <> 'System'
AND attach2.Service = @service

)

Any feedback, especially more performant ways of achieving the same thing task welcome.

Microsoft Enterprise Library Rediscovered

Brilliant.

I have just accidentally rediscovered Microsoft Enterprise Library. A set of common "building blocks" for .net applications. I used version 3.1 on an old project back in 2007 and it was a real time saver.

I have just downloaded v4.1 and it looks like it covers lots more. Will post more thoughts when I have had more time to figure it all out.

Unit testing is dead. Long live peer reviews.

Just a quick update to the unit testing trial we were conducting….. Management canned it. Due to the iterative development approach we follow it would have taken about three months to get some hard and fast figures and that wasn’t the sort of timescales they were looking at. Despite this I am still valiantly plugging away trying to prove the case for unit testing and hope that the decision will be reviewed in the coming months.

One of the more interesting measures that have been introduced to ensure quality on the project is peer reviews. Following each completed piece of development work a senior developer is assigned to review the code we have produced. Peer review as I understand it is a process of code review where code is pored over, design decisions challenged and suggestions for improvement debated. At my organisation it has been implemented as a checklist of things that should be done, with the focus not on quality, but getting ticks in a box. Very frustrating.

A tweak to the unit testing methodology

Just a quick update on a change of methodology from my earlier post.

We have decided to scrap the control team. It was deemed too expensive in terms of man hours as we are only trialling the concept.

So my team is now the "unit testing" team. Any regression defects that arise from this development stage are to be tracked back to individual pieces of work. This will hopefully show how many defects can be attributed to a piece of code with a unit test as opposed to code without. As a proper unit test should catch the majority of defects before system testing we will also be counting the number of defects our team tester finds from our code.

We will meticulously record the time spent on development and on writing unit tests, hopefully giving us some idea of the time overhead that comes with writing a test.