NOT NULL WITH DEFAULT

[stoggers]

Hi,

Just in a position where I have to maintain a database and I find that all the NULLable columns do not have defaults.

I cannot think of any reason why this should be the case and has the implication that any insert statements need to supply values for all columns.

Is there any justificaion for nor having a default?

Regards,

Mike.

 

[gregsimpson]

It is very often the case that NULL columns do not have defaults. A NULL value represents an unknown state. An example I could think of off the top of my head would be a leaving date for an employee records system. Clearly not all employees will have left so the value could reasonably be said to be NULL.

The following gives a reasonable explanation of when you might use NULL without a default.

http://www.devx.com/upload/free/features/vbpj/2002/04apr02/jf0402/jf0402-1.asp