With this hotvamp you can exercise on a nearly daily basis praticing a lot of diffrent queries and sql management commands, thus keeping a basic knowledge of the Sql oiled even if you do not deal with it on a daily basis: consider this file the equivalent of piano scales to a pianist: a boring daily duty that none the less is necessary to keep your fingers ready to play the real sonatas any moment you are asked for, or you want to impress the lady...
 
The utility of this ample scripts mostly relies upon the fact that, facing a query request, you pause and think before crafting your query. It may be time consuming, although you're not supposed to practice daily on really all of these queries: the shuffle button may help you in this case, or also the Get Num button: for upon providing a number for this latter feature, the index from which the subsequent queries are listed and grabbed gets updated to such number as well.
 
None the less, the more you spend your time thinking about your query before writing it down, the greatest the effect; also, if upon checking you get an Error, you may consider selecting the do not show results automatically checkbox so that you can think over and re-craft your query without viewing immediately how the correct version would have been: this would really maximize.
 
Last but not least, the checking process (the process that checks for the correctness of your query after you have written it, that is) takes avail of a script that is not case sensitive and allows for whatever amount of whitespaces or new lines characters. Whenever possible, it also allows for cell names not necessarily identical to the suggested ones, namely whenever possible the checking scripts attempt to focus only on the keywords, regardless of typos or so in the cell names which are not keywords.
 
The form relies on regular expressions to perform such checks on the validity of all your inputs; such expressions may have occasional minor shortcomings (example: the script checks if you open and close apexes for Strings, but doesn't check whether they're both single or both double apexes: under any practical point of view, this won't affect the validity of the tool, whereas conversely this approach of leaving out the trifles, shortens the already long coding that works in the background to serve you); but such shortcomings have been crafted to minimize the impact: so on the whole the utility of this tool for sql practice is really sound, and makes it unique on the net (at least so far!).
A second and most remarkable example of "shortcoming" is that when you have to define multiple constraints, first goes the DATA TYPE, then the most important constraint, the the one depending on it, and among them the keyword named DEFAULT goes last: example:
create table fooname(foofield int primary key auto_increment default 0)
Allowing for a different order would have been possible, but would have made the scripts even longer you see: this file already contains hundreds and hundreds of lines of code just for the SQL examples.
To workaround this, just craft your SQL answers following carefully the type of requirements as they are listed in each question: moreover this way of connecting the technical version of a SQL command to a detailed request firstly formulated in strictly human terms and consequently following such terms requirements literally and diligently step after step, is the procedure that is better poised to let you learn SQL accordingly to SQL gurus like Michael J. Hernandez and John L. Viescas.
 
I also suggest to you always to read the tips (in the test form they appear in the last field at the bottom of the form itself as soon as you've clicked the button to check the validity of your query/expression).
Some maybe trivial or "petty", but a few of them are precious insofar they've been crafted after the conceptual difficulties I myself had to overcome: and such difficulties, since I have no teachers, are very likely to be analogous to yours!
If you want to print out all the tips in one popup window, just