Re: bug or feature, <> 'blah' does NOT work with null records

[Jigal van Hemert]

From: "Harald Fuchs" <hf0722x@stripped>

> Yes, of course.  "NULL <> 'blah'" returns NULL, and that's perfectly
> standards-conformant.

Furthermore, it's quite logical.

NULL is meant to indicate that the value is unknown. If a value is unknown
it can be anything.
So, in the example `col` <> 'blah', col can be anything, including 'blah'.
If you take that into consideration the only outcome of `col` <> 'blah' if
`col` = NULL *must* be NULL!

Fortunately there is function COALESCE() that will return the first argument
that is not NULL. In case of NULL values you can use a default value for an
expression: COALESCE( `col`*2, 14) will produce 14 if `col` is NULL.

Regards, Jigal.