Constraints and Integrity

Just sticking some notes in here on this:

PRIMARY KEY constraint enforces entity integrity. It is a type of unique constraint that does not allow NULL values.

FOREIGN KEY constraint enforces referential integrity.

UNIQUE constraint guarantees that a column contains unique values in each row (can have one NULL value).

CHECK constraint enforces domain integrity.

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Learning

I feel a little like I’m drowning because I don’t have exactly the right background for what I’m trying to become. I looked into going for a Master’s degree in computer science. I don’t have the right classes to get accepted into the program at the school I graduated from.

I looked at getting a second Bachelor’s, but the local university is not accepting applications for second bachelor’s or non-degree-seeking students.

So, I decided that I should work on some certifications – I know how to think logically, but I don’t know all the fiddly little bits about SQL or even database structures. Since I don’t know where to start, I’m going to start with Microsoft certifications.

I know that there is debate about whether or not certifications are worth anything, but the best argument I’ve seen is that it can give you a focus for your individual study.

The first one I’m taking is MTA: Database Fundamentals. I know the MTA isn’t that valuable (or valuable at all in the job market), but I thought I should start with basics.

I bought the Official Study Guide. I’ve been watching the videos on Microsoft Virtual Academy.

I found some other videos on YouTube.

I bought a practice test at MeasureUp.

The test is concentrated on SQL Server and I’m working more with Access, so I’ve set up a lab environment on my home computer to work with it.

Focusing on the first test

In my post titled Learning, I talked about beginning to study for the MTA 98-364 test.

I started out trying to take the practice tests on MeasureUp.com without enough preparation. I took them in “study mode” since that I way I could see answers and take notes. I was only scoring 50-60% at first, and I knew it was because I wasn’t really prepared.

I took notes from the test questions and started to get better scores but still didn’t really feel like I have a handle on anything.

I finally actually started going through the main book I’m using and taking notes. I read the reviews for the book, and many say the book doesn’t help much, but I am finding it fairly helpful.

It’s filling in some gaps in my knowledge, especially because I’m such a beginner. But there are some frustrations.  There are questions at the end of each chapter. But I have no way of knowing if my answers are correct. I could not get access to any materials from the publisher because I’m not in school or an instructor.

I found two fairly decent study sources online that have the same questions, but the answers on both sites don’t always agree with each other and on a couple questions, I’m pretty sure they’re just plain wrong.