What is O/R Mapper?

O/R Mapper (Object-Relational Mappers) is a programming technique for converting data between incompatible type systems in databases and Object Oriented Programming languages. (# Ref)

What does it do?

The generated code from the O/R Mapper handles all of the steps that you would normally have to code yourself, saving you from having to:

• Find the database server.
• Log in and open a connection to the database server.
• Select the particular database containing the information you want.
• Find the correct table.
• Find the correct row.
• Read all the values for that row.
• Convert every type of value from its SQL data type into the .NET data type while checking and handling the possibility of a null value.
• Present those values in a strongly-typed format, so the consumer knows exactly what kind of object to expect (string, integer, array, etc.) and there are no surprises at run-time.
• Create a container to temporarily hold the values while they are being modified.
• Retrieve data from another row in a related table.
• Manage which values have changed and make appropriate INSERT’s, UPDATE’s, and DELETE’s in the appropriate tables in the database to reflect those changes.
• Close the connection.

What is LLBLGen Pro

LLBLGen Pro is a complete O/R mapper and data-access tier generator for .NET. It generates a data-access tier and business façade/support tier (in C# or VB.NET), using an existing database schema set. The generated .NET code is provided as a Visual Studio.NET project that can be added to a solution or compiled separately. (# Ref + More Info)

LLBLGen Pro Features

A key feature in LLBLGen Pro is dynamically-generated SQL. When retrieving or manipulating data in a database, the SQL script — the code understood by the database — is generated at run-time based off the requested information and dirty flags in each entity’s fields. This enables a generic save entity function on the Data Access Tier to produce different and optimized SQL code each time it is called, optimizing bandwidth usage and database load. (# Ref)

• LLBLGen Pro will completely auto-generate the data access layer. You do not need to do any hand-coding in this layer
• LLBLGen Pro will optionally generate a business logic layer shell for you to get started with your business layer. You do not have to understand the intricacies of inheritance and making custom classes to take advantage of business logic classes; in LLBLGen Pro these classes are intuitively organized, powerful, and infinitely extendable.
• LLBLGen Pro collections and entity objects are bindable, making them extremely easy to add to .NET controls. This can reduce the size of your UI layer.
• Changing the database application and the data access layer without affecting the business logiv and UI layers is actually possible with LLBLGen Pro. If you migrated your database schema and stored procedures to a new database application, refraned from using any database-specific features and your schema matched exactly, you could actually re-generate your LLBLGen Pro data access layer and not make any other changes to your application.

# Ref: Rapic CSharp Windows Development. pp. 17

LLBLGen Pro Objects

• Entities: Every “Row” becomes an “Entity”
• Collections: Every “Table” becomes an “EntityCollection”. Collection classes eliminate the need for DataTable objects and are both strongly typed and bindable.
• Entity relationships: Build into each entity are all relationships in the DB involving that table. You can either get a single entity or an entity collection depending on the type of relationship.
• Typed views: Views in the DB can be wrapped as strongly-typed DataTable. Typed views are read-only; new LLBLGen Pro allows you to add a view from the database as an entity as well as a typed view.
• Typed Lists: Typed lists are the only objects created by LLBLGen Pro that do not correspond one-to-one with DB objects. It’s handy when you need very specific information that does not necessarily correspond to a single table or entity or you only want to grab a subset of information for a given set of table.
• Storedprocedures caller classes: Storedproc that you select will be wrapped in a layer of code. While the parameters of the stored procedures are strongly-typed, the result set is still an untyped DataSet.

Project Types: SelfServicing Vs. Adapter

There are two types of LLBLGen Pro Projects namely – SelfServicing and Adapter.
# In SelfServicing template group, entity objects are responsible for their own persistence (saving their own changes to DB).
# The entity class itself contains logic to know which fields were updated and where to find the database.
# Lazy Loading is useful cos’ it abstracts the specific DB call from the upper layers of code.
# Adapter template group: uses an object called a DataAccessAdapter to interact with DB
# SelfServicing: bundles persistence inside entity objects
# Allows data to load itself automoatically as it is needed without explicit commands.

I’m learning new things these days and am just sharing some notes here. I’m still learning and these technologies are very new for me, hence my notes gonna have heaps of errors and wrong information. You are most welcome to correct them, fill some more in and share you notes with me too. Alright, so we are set to go.

I’ll be updating this post with links so still tune.

• Windows SDK Setup
• Installing .NET 3.0 and Orcas
• Microsoft® Visual Studio® 2005 Service Pack 1
• Basic N-Tier Recap
• Introducing O/R Mapper and LLBLGen Pro
• LLBLGen vs CodeSmith
• Dear DotLucene
• Greetings Subversion and TortoiseSVN
• Source Control Resources
• Versioning Models
• More coming soon…

All the notes are subject to change as I’ll be filling in with more info later.

I’m in love with the new LCDs. They got 19″ Lenovo L192 Wide Tft monitors for their IT section. Last time they have pretty cool IBM flat screens and now upgraded with Lenovo wide screens.

The Lenovo L192 Wide Monitor offers users to view images in a 16 x 10 wide aspect ratio. It is available in business black. This monitor is best suited for complex spreadsheets, multitasking, general business applications and multiple-monitor environments.

Features & Benefits:

• 19-inch (483-mm) viewable image size
• Optimum resolution: 1440 x 900
• Tilt stand for viewing comfort adjustments
• 16 x 10 aspect ratio
• Analog attachment
• Internal power
• Meets 100 mm VESA requirement

Specifications: Lenovo L192 Wide Monitor

I hook it up with my ugly laptop screen and use it as dual extended monitor.
What a sensational sight! hehe

Obviously, I’m for “Not to Cut”. How can it be good, if you get cut?
This is outrageous, demoralizing, depressing, disappointing, demolishing, deteriorating, d…d…d…damnation.

Socialist Measures? I just don’t understand any of those socialist, communist, democratic, republic, lic, flic, slic, nist, dick!

F%*# Banimarama, if they are blaming on him, but I pretty much doubt it’s cos’ of political situations. Some teams are just slack and management is taking this opportunity to slide along with current situations.

It’s already been crappy pay and 15% is just too much to bear.

(Ignore me, I’m just screaming out my work related issues.)

Incase you haven’t heard, there are some vacancy openings here at our beautiful Fiji islands.

Due to recent crisis, a few job opportunities coming up which you might like to take advantage of. The opening positions are as followed :

Application for Fiji Prime Minister and Carbinet Minister Jobs

Military commander Voreqe Bainimarama says people can apply for the job of Prime Minister or Cabinet minister in his interim government.

Application for Publisher at Daily Post

“We’ve had death threats, bomb threats and our publisher is in and out of hiding after being named by Commander Bainimarama on Friday,”

The situation has led the publisher, Mr Alan Hinkling, to recommend asking the Australian High Commission to support applications by staff for asylum.

Unfortunately, I couldn’t get hold of the requirement details for the above positions but I bet you got to have some sense of adventure. Already a friend of mine is going for PM position and buying my vote. I think lunch/dinner would be fine. haha
So just try your luck, you never know you might be the next Fiji PM in line.

Read latest Fiji crisis news on Fijitimes.

After many mishaps and frustrations, I’ve successfully installed .net 3.0 and all other extensions. I find installing .net 3.0 a painful process yet your case might be as easy as 1 2 3. Just for my own note and whoever with the similar situation can cross-check, I’ve listed down the followings.

You need at least half a day work in installing all required setups for .net 3.0, not including the downloading time for installer files. Make sure you already have VS.Net 2005 installed. Ofcos have WinXP with all those latest service packs, just to be sure.

• Clean up your machine and get at least 6 GB freespace,
• Remove any previously installed versions of beta and RC releases,
• Follow the installation order and notes below.

Order of Installation
Installation order plays an important part here. You must follow the following order to run files smoothly.

1. Microsoft .NET Framework 3.0 Redistributable Package : dotnetfx3setup.exe (2.8MB)
2. Microsoft® Windows® Software Development Kit for Windows Vista™ and .NET Framework 3.0 Runtime Components : Setup.exe (400KB)
3. Visual Studio 2005 extensions for .NET Framework 3.0 (WCF & WPF), November 2006 CTP : vsextwfx.msi (3.64MB)
4. Visual Studio 2005 extensions for .NET Framework 3.0 (Windows Workflow Foundation) : Visual Studio 2005 Extensions for Windows Workflow Foundation (EN).exe (6.46MB)

N.B: #2

The setup file will load the sdk installation wizard which do direct installation. If your net is crappy like mine or if you need to install on multiple machines, then direct installation is just not right. In that case, you either need an installer DVD or get an iso image file like this one: 6.0.6000.0.0.WindowsSDK_Vista_rtm.DVD.Rel.img (1.15 GB) (My friend downloaded from somewhere…)

You might need Virtual Clone Drive to run that iso image file. Free Download from here: Virtual Clone Drive 5.1.4.5.

These are some of the problems I faced while installing and the fixes.

Error: WWF extension for VS.net

SDKSetup encountered an error: Unable to find the file SDKSetup.cab at the installation source. The most likely reason that you received this message is because the source location of your original installation is unavailable. If you installed from a DVD please re-insert the DVD. If you installed from the Internet, please check your connection.

Fix: Place the WWF installer exe file in the same directory as your iso image file, then run again.

Error: SDK Installation

Error 1303. The installer has insufficient privileges to access this directory: C:\Config.msi. The installation cannot continue. Log on as administrator or contact your system administrator.

Fix: Ignore and click “Continue” button. Might get this error twice or so, just ignore and continue installation.

N.B: Make sure you log in as Administrator to your system and checks on C: drive that you have given full previlidge to “System” or “Everyone” account. Better to have full access on “System” account. Shouldn’t have any problem if you installing directly from internet.

Well, at least I’ve taken one big step in upgrading to .net 3.0. Now all I need to do is, start digging and go dirty with it. I got a few online labs to play around and some good resource sites. I’ll write more about it once I get started. I’m getting my eyes on WWF labs at the moment. I’ll keep you updated.

Tell me about your installation experiences and share some tips/resources too k?

Technorati Tags: .Net 3.0, installation, Framework, SDK, WCF, WPF, WFF

I’m starting my hand on sql05, vs.net 05, sdk 3.0, WCF, WPF, WWF etc etc… and…

Arrgghhhhhhhhhhhhhhhhhhhh!!!!!

Windows SDK Setup Wizard

Setup file: 400KB
Installation: 958.8MB ?!!!??!!!!
Estimated Download Time: 20 Days, 18 Hours !!!!!!!!!

Arrrggghhhhhhhhhhhh!!!!!!!!

That is just so great! What am I to do???
I want to start test now, NOW! NOW! NOW!!
Garrrhhhhhhhhhhhhhhhhh!