On Friday 17 July 2009 12:45:47 Mikael Krantz wrote:
> It might be that your column may be NULL as well as TRUE or FALSE. I
> am no expert in this matter though.
Nulls also need to be considered when attempting to substitute purportedly
equivalent clauses. But in this case it wouldn't actually matter, because
WHERE foo <> TRUE
and
WHERE foo = false
would both omit the row if foo is null. Both expressions only return true if
foo has the value "false". But again, this is data type specific knowledge.