List:General Discussion« Previous MessageNext Message »
From:Jigal van Hemert Date:October 28 2004 9:50am
Subject:Re: bug or feature, <> 'blah' does NOT work with null records
View as plain text  
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.

Thread
bug or feature, <> 'blah' does NOT work with null recordsmatt_lists25 Oct
  • Re: bug or feature, <> 'blah' does NOT work with null recordsKeith Ivey25 Oct
    • Re: bug or feature, <> 'blah' does NOT work with null recordsSGreen25 Oct
  • Re: bug or feature, <> 'blah' does NOT work with null recordsPaul DuBois25 Oct
  • Re: bug or feature, <> 'blah' does NOT work with null recordsHarald Fuchs28 Oct
  • Re: bug or feature, <> 'blah' does NOT work with null recordsJigal van Hemert28 Oct
    • Re: bug or feature, <> 'blah' does NOT work with null records(Pete Harlan)29 Oct
  • Re: bug or feature, <> 'blah' does NOT work with null recordsHarald Fuchs28 Oct
  • Re: bug or feature, <> 'blah' does NOT work with null recordsJigal van Hemert28 Oct
  • Re: bug or feature, <> 'blah' does NOT work with null recordsMartijn Tonies30 Oct
RE: bug or feature, <> 'blah' does NOT work with null recordsJay Blanchard25 Oct