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Can anyone clearly explain what the difference between null and nothing? On the 100 question quiz it states that null in sql represents nothing but I have also read that a null is an uninitialised variable and can be tested for using isnull(var) and nothing is nothing and can be tested for using isnothing(var). So what is the difference between null and nothing??
Thanks
[QUOTE=dubdownunder;27605]Can anyone clearly explain what the difference between null and nothing? On the 100 question quiz it states that null in sql represents nothing but I have also read that a null is an uninitialised variable and can be tested for using isnull(var) and nothing is nothing and can be tested for using isnothing(var). So what is the difference between null and nothing??
Thanks[/QUOTE]
In oracle there is no difference between null and nothing. Null is nothing but absence of value. For detailed explanation follow the link
[URL="http://thinkoracle.blogspot.com/2005/05/null-vs-nothing.html"]http://thinkoracle.blogspot.com/2005/05/null-vs-nothing.html[/URL]
both NULL and nothing represents absence of data.
Null is used in databases to represent nothing .
Null in oracle is an absence of information. A null can be assigned but it can not be equated with anything: even itself.
A null is not equla to 0
a null is not equal to nothing
a null is not an empty string
null is an unknown value
[QUOTE=susarlasireesha;27683]Null in oracle is an absence of information. A null can be assigned but it can not be equated with anything: even itself.
A null is not equla to 0
a null is not equal to nothing
a null is not an empty string
null is an unknown value[/QUOTE]
null is not equal to nothing ?
Is there any difference between these words
nothing
no value
absence of value
If there is nothing in a column how will you find it out without using IS NULL ?
NULL means "Not Known".
Not knowing something is very different from knowing that something is nothing (for which the empty string '' is provided)!
here(in sql) nothing indicates blank (we dont enter either keyword "NULL" or any number)
Thanks & Regards
Trainee_tester