I agree with the other replies to you. I've actually worked with a couple of the different test makers (working in a group, evaluating old questions and writing new ones). When you take a test, or want to be authorized by MS, or CompTIA or Cisco, etc, to write a book, or teach a class, or create practice tests, you have to sign NDAs (non-disclosure agreements) promising not to divulge the contents of the test. When you take the test you see (for most of these tests), less than 100 questions out of their pool (which in some cases include several thousand questions). If you take the test again, most of the questions will be different. So taking the test twice won't help much. These questions in the pool each belong to at least one domain of the test.
Back to the class/book/etc making. You cover, say, 80% of the test material (based on a detailed breakdown of the half-dozen or so domains). Now a student with a photographic memory memorizes everything in your book or class. Assuming they already know at least something about test-taking techniques, and also a bit of the subject at hand, they might just barely pass. Most of us don't have that eidetic memory:( But if you took one person's class, and another person's book, and yet another's practice exam, each with about 80% of the test material, you'll end up learning 90%+, which makes it easier to pass without being perfect.
So, how to pass a serious test? Study as many resources as possible (except brain dumps). Especially figure out how to do practice labs: beg, borrow, or steal (OK, please not the last one) some computers and whichever equipment you need. For your SQL stuff you want at least two or three good PCs so you can run 2 SQL Servers (virtual or dedicated), plus at least a couple client PCs. For some students starting into IT, I recommend going to the thrift store and buying 2-4 PCs AS-IS so they can get the experience they need for the A+ class trying to get at least two good PCs out of that $50 investment. Later they use them for their networking classes, their MS classes, etc.
So, practice on real equipment (virtual or not, remote or not).
Study from multiple sources.
Be sure when you take the practice exams that you look at every answer, right or wrong - because I can almost guarantee some questions will be based on those wrong answers (e.g., question 8 had A-D multiple choice answers. B was correct. A was a distractor and meaningless. C was wrong because of X. D was wrong because of Y. But your real test will have a question about X, and now you can use answer C on THAT question).
Study test taking techniques. Do a search on Google for "The Woolygoggle test" and the first (or one of the first) results will be a PDF from www.wiu.edu, titled "MASTERING SKILLS IN TEST -TAKING - WIU" Study that pamphlet, and only then take the woolygoggle test at the end. By the time you get to that test you'll be able to correctly answer questions about woolygoggles - something you've probably never heard of before. Some of the questions you can't get the answer - but you can cut the choices from four (25% chance of being right) to two (50% chance of being right). On a real test, that can make the difference between failing by two points or passing with 5 points to spare. {If you're that close, I'd advise afterwards looking at the test results to see which subdomains you did poorest on and studying those areas :-)
For most of the earlier exams I also add - get out their online and look for additional resources - there are free (and safe) sites for studying for your A+ or MCSA. Who knows, their might even be someplace for SQL.
And remember that your membership here allows you to ask questions when you aren't clear about something.
And yes, both MS and CompTIA do have some answer choices intentionally designed to trick you.
