SQL and some remarks

Since there is no time now to talk in details about SQL, I'm pointing out some notes and links to articles and websites that discuss SQL in a simple manner. So, if you have questions, leave a comment.
http://www.w3schools.com/sql/default.asp
http://www.codeproject.com/KB/database/sqlintenmin.aspx
http://www.databasedesign.co.uk/sqlselectshortsummary.htm
http://msdn2.microsoft.com/en-us/library/ms189463.aspx

SQL Constraints

http://www.1keydata.com/sql/sql-constraint.html

Notes:

1. SELECT TOP n WITH TIES will not select all repetition, instead it will select repetitions till the first truncation. And it is only to be used with ORDER BY.
2. To get the current date use the GetDate() function.

Here is a file containing some windows applications and SQL notes thanks to Abd El-Rahman. I haven't review it's content, so, here is the file[^] as it is.