Difficult Concepts in Unit 10

The specific concepts that I found most difficult in Unit 10 were normalization, null values and extended regular expressions.

The issues I have with normalization at this point are that it still seems very theoretical and I'm having trouble conceptualizing it. I think as I actually work with a database design it should make more sense. It helps to see lots of examples.

Null values may work out in the same way - with experience. I found it confusing to try and follow the "Working with Null Values" explanations in the MySQL.com tutorial.

My question about the extended regular expressions ("regexp") is Why? What's the point? The regular SQL pattern matching queries seem to do the same thing and for the most part seem simpler to enter. The only example given where there was an advantage to using the regexp approach was with "SELECT * FROM pet WHERE name REGEXP 'w';" where as the tutorial points out "it is not necessary ...to put a wildcard on either side of the pattern to get it to match the entire value like it would be if you used an SQL pattern." Otherwise, I don't understand why you would use the regexp commands rather than the SQL commands. Perhaps I should look for a Wikipedia article on extended regular expressions or go through Section 11.4.2 (Regular Expressions) in the MySQL tutorial to get a better understanding of this.

Overall, the whole database design exercise (Assignment 4) was difficult for me when I actually had to come up with the ERD for my proposed database. I don't know if I got it right - having the appropriate entities and/or attributes.

As a side note, I really had fun playing with MySQL - creating the menagerie database and tables, using the different commands and actually being able to make things happen!