Understanding SQL in depth : <p>at first i want to say sorry for the bad gramar, i dont speak or write in english with regularity.
But here is the purpose of the question ,</p>

<p>Im a newbie programer currently working in a company that develops heavy data-base oriented products, and due to these reasons im currently working on my knowledge to achieve more results and grow inside of the company and also get more close to achieve the excellence while coding.
Most of my work actually focus on import some data from a data-base to another, having to treat these datas so it can fit the data base that will get the data.
Since it normaly have a lot of rows and even archives data-bases that does requires very efficient query's to not lose any time , more and more often im seeing myself in a situation that  i require more knowledge.</p>

<p>Few weeks ago i started to understand a little more of how SQL works, and it does took off that beginner feelings of CRUD being a static sentence, specially after i started to put subquerys on the FROM and making some functions inside of select and prepared statements BUT STILL, it lacks of something to give the true enlightment to the coding art to understand NOT how it is writen but how and why it works .</p>

<p>Its a very complicated question even for who asks and i cant even imagine how it is for who answers .
If there is someone that understood my point of view and has pacience to answer this , i really believe that it will help a lot of peoples that got inside of SQL programing.
Thank you.</p>
