SQL for not registering employees for conflicting appointments!


I was once asked by a fellow colleague if it was possible to have an SQL statement that would not allow employees from being registered to events that occur simultaneously.

Scenario

Consider a database that stores a list of persons and a list of events. Employees would eventually be registered as event attendees. It is possible that multiple events occur at the same time and therefore it is required that the SQL statement prevent any persons from being registered as attendees of conflicting events. It was required that the solution be all in one SQL statement for some reason whatsoever.

The SQL solution is found attached together with a supporting report! As always all feedback and queries are welcome!

Register employees for non conflicting events

Filfla


One of my favourite diving sites is the Um El Faroud at Wied iz-Zurrieq and one of my very first shots with the new camera and underwater housing was as I surfaced from a dive. It was more luck than skill back then but yet a great addition to my collection.

Valletta Waterfront, Malta


I had just got hold of my new Canon Powershot A710 IS and headed down to the newly refurbished Valletta Waterfront around July 2007 and this was one of my very first shots! The waterfront was not yet bloated with restaurants and the real beauty of this site can be appreciated!

Oracle DBMS 11g Release 2


Out of sheer curiosity I had decided at the beginning of the year not to satisfy myself with Oracle Express Edition and started experimenting with Oracle 11g Release 2. It wasn’t long before I got it up and running on Windows systems and was able to administer it with ease thanks to the ample documentation found. The same can be said for installation on Red Hat Linux which is officially supported by Oracle. Being a little bit curious I wanted to test it on my two favorite operating systems, CentOS and Ubuntu.

Well it wasn’t all that easy and there isn’t much documentation for those OSs. I spent a lot of time reading various postings then testing and experimenting myself, documenting all along the way. Finally I managed to get Oracle working for CentOS 5.5, Ubuntu 10.10 and Ubuntu 11.04 with good documentation. This will be a continuous work in progress and will plan to keep updating it.

Today I found some time to fix the presentation of the document and decided that it is fine time to share it with the public. So here is the link in the way that I would have loved to have found it on the net: Oracle 11g R2 Guide

As usual all feedback is more than welcome!

Oracle Express Edition 11g R2


One of my subject areas is information systems, and the undisputed number one brand in database systems is obviously Oracle. Recently Oracle have improved their light version of their flagship product the Oracle Express Edition and have also updated SQL Developer. I had prepared an installation guide for both software which I have updated for public use!

If it interests you here is the link: Oracle Express Edition 11g Release 2 and Oracle SQL Developer

Do leave some feedback for this guide!

The first step of the trail!


You first can’t walk, then you start to crawl. With some help you make your first steps then you run! Every task is our life is a trail and we start by the first few steps. My first steps in blogging were due to a post-graduate course in vocational teaching which I discontinued.

From time to time I would write articles or pieces of work which I would keep with the intent of publishing at a future stage! Well that day has arrived! I collected a few articles which I intend to publish gradually!

So here is my blog! A software consultant with a specialization in information systems, Java, PHP, Linux! An affection for the sea, diving, photography, camping and movies. Loved by caring parents, an elder brother, an amazing wife and great friends. Respected by fellow colleagues, students and superiors!

My name is Frankie Inguanez and this is my blog!