Can someone explain the difference between Nullable and Is_Nullable

[SBendBuckeye]

Hello all,

I have a decent working knowledge of Sql Server, although I don't work with it constantly. One of the things I have never quite understood is how Nullable and Is_Nullable differ. BOL says they are different, but does not elaborate. Could one of you be so kind? Thanks in advance!

Have a great day!

j2consulting@yahoo.com

 

[vongrunt]

Is_Nullable is three-state (yup, nope and unknown) and conforms to ISO rules (blah).
Nullable is two-state (yup and nope).

Both describe the same thing - whether column accepts NULLs or not.

------
"There's a man... He's bald and wears a short-sleeved shirt, and somehow he's very important to me. I think his name is Homer."
(Jack O'Neill, Stargate)

 

[jbenson001]

How do you even use them? I can't find Is_Nullable in BOL.

 

[vongrunt]

Various standards-compliant features should have it - INFORMATION_SCHEMA views, results returned by sp_columns...

------
"There's a man... He's bald and wears a short-sleeved shirt, and somehow he's very important to me. I think his name is Homer."
(Jack O'Neill, Stargate)

 

[jbenson001]

Ok ..thanks...

 

[SBendBuckeye]

Sorry, but I'm still confused. If I want to read sp_Columns and determine whether or not a field is nullable, which one do I use, nullable or is_nullable? Thanks again!

Have a great day!

j2consulting@yahoo.com

 

[bborissov]

Nullable

Borislav Borissov