Difference between NULL and Empty


Difference between NULL and Empty


Could some one please explain me the exact difference between NULL and Empty values for a field from a database perspective ? I do understand the concept that NULL is absence of a value and empty is a value but just empty. But I am trying to get a conceptual understanding as to how database stores these values and are they both treated differently.

I am also trying to understand if empty can be quantified as '' ? Is it Valid to attribute this expression to empty ?

I have tried reading about this at various places but i still end up getting a vague idea. Any help towards helping understand this issue could be great.


Re: Difference between NULL and Empty


You know well about the null, it is absolutely absense of a value, and if you find the meaning of empty the google defines it as "containing nothing; not filled or occupied" So you can say NULL is a relational databases term for empty. 

I dont know why are you comparing empty and null. if by empty you mean an empty string, for example a space, then empty string will obviosuly take 1 byte to store this as a character. But a null is complete absense of value.