My First project @ Cognizant – ALDSP and XQuery

My First project @ Cognizant – ALDSP and XQuery

On 23^rd September 2009, I joined Cognizant, after the first day induction program, I was asked to work on the project which was already started. In that project, project lead gave me a list of technologies which are going to be used.  I was offered with the backend part which was considered as tough part in the project

ALDSP and Spring Batch

Backend part – this project was designed in such a way that, batch will generate image and xhtml files ( I was not there when the design decisions were made. Before I join cognizant all these decisions were made).

I was really happy to know that, I got a chance again to work using my favorite framework – Spring. But there was couple of new technologies involved with spring batch. I always want to be a good learner, I try to do so. I have started learning ALSDP (a bea weblogic product). But un – fortunately / fortunately the basic setup / platform was already developed.

I started learning ALSDP, now I am really confident that I can convert any complex SQL query to XQuery and I can do any kind of data manipulation in XQuery. Now I am writing this post to let all the beginners to have the basic understanding about ALDSP and XQuery.

Introduction to ALDSP and XQuery

As I told before ALDSP is a Bea weblogic product, it’s helps us to create web service easier.  ALDSP – Aqua Logic Data Service Platform is a tool to develop web service and it uses XQuery language to fetch data from the database.

It has two types of DS files ( logical and physical data service).  

Physical – this DS acts as a physical table / view. We can create this DS from a table or view or stored procedure or SQL query.

Logical – We will have all the data manipulation process here. Logical DS is further divided into two types.

 1. Entity data service – here we should have functions which is getting exposed as a web service.

2.  Library data service – here we should have functions which is not getting exposed as a web service. All the function written here will acts as a reusable methods. This DS can be imported in the various entity data service.

Best Practice

DO’s

1.       All the DS files should have schema (xsd) associated with it

2.       Physical DS should only have the functions like create and table / view function.

Don’t (usually I will concentrate more on the Don’t part. Whatever be the technology, if we avoid all the don’ts, we will definitely have a standard code)

1. Physical DS should not have any user defined functions.  
2.  Entity DS should not have any functions which are not getting exposed as a web service.
3.  Logical DS should not have any functions which are getting exposed as a web service
4.  Any web service functions should not be without a schema defined. 

I will keep writing more about ALDSP and XQuery on my upcoming posts.