Websites rich with exercices or explanation for SML?

fixed the issue. Will look into that further Alfresco is an open source ECM with Web Content Management . It was started in 2005 by the former founder of Documentum and engineering team of former Documentum developers, and has been built by engineers with many years of experience from Interwoven, Vignette, and other ECM players. It's a modern architecture, and is runtime-agnostic, so you can have .NET sites managed right next with Java Sites, PHP sites, etc.
Used by lots of large and medium sized enterprises all over the world (check customers list).

This might help you You are asking a very difficult question to answer.
I recommend that as an introductory read you check out Youtube Architecture on High Scalability. Youtube is a very good real-life example of how a media-centric website works.

hop of those help? Simpler way is by using Top keyword with order by to find the printer with minimum price. This will avoid the Sub query
Join the result back with product table to find the maker

SELECT a.maker,b.price
FROM   product a
       JOIN(SELECT TOP 1 price,
                         model
            FROM   printer
            WHERE  color = 'y'
            ORDER  BY price ASC) b
         ON a.model = b.model 

SELECT a.maker,b.price
FROM   product a
       JOIN(SELECT  price,
                         model
            FROM   printer
            WHERE  color = 'y'
            ORDER  BY price ASC limit 1) b
         ON a.model = b.model 

will help you You could have two remote repositories, say solution (that contains the private code), and student (that contains the public code that students need to work on).
Put all your code, except the solution, in a branch b1 in solution. Create a new branch b2 off b1 and push the private code there. Then, sync only branch b1 with the other remote, student.