6/19/2012

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

6/18/2012

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