Friday, 24 May 2013

What is a primary Key?

Tags

What is a primary Key?



A primary is a single column values used to uniquely identify a database record.
It has following attributes
  • A primary key cannot be NULL
  • A primary key value must be unique
  • The primary key values can not be changed
  • The primary key must be given a value when a new record is inserted.


EmoticonEmoticon

:)
:(
hihi
:-)
:D
=D
:-d
;(
;-(
@-)
:o
:>)
(o)
:p
:-?
(p)
:-s
8-)
:-t
:-b
b-(
(y)
x-)
(h)