Databases – Page 2 – Frankie Inguanez

Category: Databases

SQL for not registering employees for conflicting appointments!

Posted on 2011-12-14 by Frankie

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!

Oracle DBMS 11g Release 2

Posted on 2011-12-12 by Frankie

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

Posted on 2011-12-12 by Frankie

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!