SQL Delete current database

I need to delete my current database which I am using it , I googled around and found this answer:

http://sqlserver2000.databases.aspfaq.com/how-do-i-drop-a-sql-server-database.html

ALTER DATABASE myDataBase
    SET SINGLE_USER
    WITH ROLLBACK IMMEDIATE

DELETE DATABASE myDataBase 

SQL Constraints

Constraints limit the type of  data that can go into the table.
The following are the constraints:

1. NOT NULL
2. UNIQUE
3. PRIMARY KEY
4. FOREIGN KEY
5. CHECK
6. DEFAULT

SQL Joins

Hi newbies,
Want to learn SQL joins at a glance!!, here you go... SQL joins is Venn diagram representation:
A very nice picture given in codeproject.

http://www.codeproject.com/Articles/33052/Visual-Representation-of-SQL-Joins