mugaland.com Blogs

Happy New Year - 2009!

Thu, 01 Jan 2009 00:00:00 GMT

Just wanted to wish Happy New Year to everyone.

It has been quite a year - maybe not so much for having "releases" but more for evolution.

This "evolution" has been more in the direction of multi-core support for the EJ base code - a must have. This of course slowed me down on finishing the implementation of the GUI - the dot net side of it. I will try to not be distracted by the release of C++0x.

To everyone out there, again, have a fantastic 2009.

Frank

ASP.Net and Linq to Sql with Crystal Reports

Tue, 14 Oct 2008 00:00:00 GMT

Lately I’ve been quite involved with using “Linq to Sql” in various database related .Net applications and it’s not surprising that a time came when I needed to do some reporting. I chose to create reports in Crystal Reports so it would be as quick and painless as possible. I was stuck with getting the reports to work directly with my already existing linq queries. I did not want to bust down and figure out the usual standard way of setting up such a report. I just needed to believe that Crystal Reports can just take a linq query and voila! All done. It turns out that this is quite the case at least with Visual Studio 2008.

First create your aspx web page and insert the below. You can just drag the “Crystal Report” component from the tool box to your page:

<%@ Register Assembly="CrystalDecisions.Web, Version=10.5.3700.0, Culture=neutral, PublicKeyToken=123456789xxxxxxxx"

Namespace="CrystalDecisions.Web" TagPrefix="CR" %>

<CR:CrystalReportViewer ID="CrystalReportViewer1" runat="server" />

<CR:CrystalReportSource ID="CrystalReportSource1" runat="server">

</Report>

</CR:CrystalReportSource>

Then in your “.cs” file create your query and assign it to the ReportDocument object of CrystalReportSource1. Make sure you have a “Select New” and a “ToList()” so that the report gets the data as it requires.

override protected void OnInit(EventArgs e)

{

var query = ( from q in somedatabase.sometable

where d.somefield == "field"

select new { q.somefield, q.somefield2}

).ToList();

CrystalReportSource1.ReportDocument.SetDataSource(query);

}

You obviously also need to create the Crystal Report as defined above as “CrystalReport.rpt”. The only catch is that the report needs to know the fields defined with “Database Expert…” inside the Crystal Reports designer. You need to have at least the fields as the output of the linq query. You can do this with a data set or use the table from that database, whatever works to get those fields to match the linq query.

That’s it. No problemo.

EarthJet?

Fri, 29 Aug 2008 00:00:00 GMT

Greets! It’s been a very long time since anything has been posted here. Did the poster go postal? Hehehe.

Well, things have been quiet here but not forgotten. As for EarthJet, the target date is end of the year.

I’ve been working with various implementations and versions of the base code for improvements and efficiencies. The front-end will be run on .Net while the back-end (base code) will run natively. So far I’ve managed to provide for variable sized particles without too much performance loss. In the midst of the next computer revolution, another important factor I’ve been delving at is that the base code must run multi-core. What would a DEM program look like if it only ran on a single processor? So, the first struggle I’m combating is the choice of an API, runtime, etc. needed to have EarthJet running on a multi-core processor. If you are computer literate, you’d know what I mean. Most programming languages are suited only for single-core and when faced with a means of a language well suited for the new revolution you’re at a crossroads with the present language. What will I do? Where will I go? Either I stay with the current language and use ingenuous methods for multi-threading or I re-write everything in Erlang, F#, O’Caml, Haskell, C#’s TPL or MPI or OpenMP… Well, it would have to be a high-performance language similar to C++. Cilk++ is one I’m keeping an eye on.

Whatever the direction, it will eventually work itself out. The end product is one bad boy that runs efficiently using whatever means to fulfill the product specs.

I’ll write some more about the dilemma of a “want to stay mainstream” software developer.

Frank

Email Working Now

Thu, 14 Feb 2008 00:00:00 GMT

I've noticed that the email agent in the contact page was returning "Failure sending mail" messages. Grrrrr... Apologies for that. It is all now working again.

Going Functional

Thu, 06 Dec 2007 00:00:00 GMT

Going Functional

No, I did not fall off the face of the Earth. I've been tied up pretty much in work and doing research and, and, and... Well before the year comes to an end I better add something to the blogging page.

My recent focus has been on getting to grips on functional programming. It's pretty much coming to a mainstream in the world of computing. The imperative style or paradigm (as they like to call it) of programming is slowly moving away from us. Languages as C++ and C# are in need for an extension that can accommodate the new functional language style. Actually, C# has already for more than a year (C# 2.0) added what is called LINQ (Language Integrated Query) and now is prepping for a final release of PLINQ (Parallel LINQ) and TPL (Task Parallel Library). All of this is for making a smooth transition to functional programming without leaving behind the tons of invested existing code behind - a smart move by Microsoft. Ideally it would be better to start over and have a language that is better suited for it, but there is really no choice but to add extensions to an existing language such as C#.

Functional programming is a very old concept. Remember the world of FORTRAN, LISP, HASKELL, OCAML? Well it's all coming back! Why? Although many inroads have been made in making programs more modular and thus manageable, we still run into trouble with complexity and "noise" for lack of a better description. The way to go is to take away features from a language instead of adding to it. This greatly simplifies the structure and the debugging process. The biggest reason really is because computers are going multi-core. You will very soon find it hard to buy a single-core computer. Yet, software does not really understand the multi-core advantage. It's been a free lunch so far in that the clock speed of processors kept gaining, automatically making programs faster and faster. Well, this will no longer be the case. Processors can no longer become faster (light speed is fixed) but be can add processors and do parallel processing. The only trouble is that programming as we have known it all these years is not very well suited for parallel / concurrent processing. However, functional programming is very well suited for concurrent tasks in that it does "parallel" better. Erlang is a pure functional language that really does "parallel" nicely by the use of message passing. It is thread-oriented and shares no memory. Shared memory is the culprit here. "Locking" is another way of managing shared memory amongst concurrent threads. Not to go way off course, the point I was trying to make is that with the advent of multi-core programmers need to change their habits.

A good place to start is C#'s LINQ that not only does database querying well (as I first thought) but also does a good job in doing general programming. Check out how one can write a complete ray tracer in LINQ here. Very impressive. Another good way to start is the upcoming new language called F#. It is the only real functional language for .Net at the moment. It is all at its beginning stages. Ride the functional language wave now!

Dynamic Queries with Linq or not?

Thu, 26 Jul 2007 00:00:00 GMT

Dynamic Queries with Linq or not

I’ve searched the internet for a possibly of generating dynamic queries

using Linq to Sql and discovered that there really isn’t anything obvious

that may be inherently possible within the LINQ scope itself.

I’ve seen a somewhat workable method for doing dynamic queries

in Mike Taulty’s blog by use of reflection: http://mtaulty.com/CommunityServer/blogs/mike_taultys_blog/archive/2007/06/15/9489.aspx

Giving it some thought, the fact that Linq has the field names integrated

as properties of the DataContext class does not lend itself to creating dynamic

queries like in ADO / T-SQL or what have you (where you simply generate the

query string before it is executed.)

Doing an “ExecuteCommand” or “ExecuteQuery<>” off of the DataContext

may do the trick, but again one is resorting to using strings for generating

dynamic queries.

A database application making use of Linq to Sql would need custom function

calls. A function like “GetAllCustomers(…)” would be all too common in a

Linq to Sql application, or not?

By Frank Neubecker

Linq To Sql, a quick way to learn

Tue, 17 Jul 2007 00:00:00 GMT

With the release of Orcas (now at beta 1) developers can create database applications like never before. Microsoft managed to extend C# / VB to also include what is called Language Integrated Query or (LINQ). Database querying can now be accomplished right within the language eliminating the need for a developer to be concerned with the database complexities as interfacing SQL queries as strings. Query interfacing is now done through use of strongly typed variables that can quickly be enumerated like that of lists or arrays.

Here are a nice set of short “Linq to SQL” videos by Mike Taulty:

Introduction to LINQ to SQL (13:00, April 16, 2007)
A Tour Around the DataContext (18:00, April 17, 2007)
Mapping Between Types and Schema (13:00, April 18, 2007)
Tools for Generating Mapping Information (14:00, April 19, 2007)
Inserting Data (09:00, April 20, 2007)
Deleting Data (15:00, April 23, 2007)
Updating Data (20:00, April 24, 2007)
Concurrency (19:00, April 25, 2007)
Joins (13:00, April 26, 2007)
Dealing with NULLs (09:00, April 27, 2007)
When Do Queries Execute? (08:00, April 30, 2007)
Deferred Loading in LINQ to SQL (12:00, May 1, 2007)
Querying with Stored Procedures in LINQ to SQL (24:00, May 2, 2007)
Modification with Stored Procedures in LINQ to SQL (18:00, May 3, 2007)
Calling Standard T-SQL Functions in LINQ to SQL (05:00, May 4, 2007)
Calling Custom T-SQL Functions in LINQ to SQL (13:00, May 8, 2007)
Inheritance in LINQ to SQL (18:46, May 9, 2007)
Transactions in LINQ to SQL (06:51, May 10, 2007)

It would be a good idea to get the basics down and start with the first video. Also, C# has now expanded into a very large superset (C# 3.0). For new developers in C# .Net, be sure to understand the basics of C# 1.0 and 2.0.