On 17/09/15 23:10, Rowan Collins wrote: > You keep defending your use of NULL, but that is not what needs > defending; it is the proposed use of an unset variable as a "very null" > state which I am questioning. As far as I know, most databases do not > have the notion of "does not exist" in tables or result sets - the > result of a Left Join failing is the same type of Null as can be stored > in a Nullable column.
The 'does not exist' requires that there IS a second field to carry the flag that 'MOT' is not required, while simply leaving it out of the result set then saves two fields. Where you have a range of data which may or may not exist only returning the fields that do exist is a lot faster than loading the whole process down with every field. Currently one has to switch off errors where is_null may be used with a non-existent field because there is no easy way to know that the field ... as a variable ... does not exist. Deprecate expand() so it's use is not possible may be another 'fix'? -- Lester Caine - G8HFL ----------------------------- Contact - http://lsces.co.uk/wiki/?page=contact L.S.Caine Electronic Services - http://lsces.co.uk EnquirySolve - http://enquirysolve.com/ Model Engineers Digital Workshop - http://medw.co.uk Rainbow Digital Media - http://rainbowdigitalmedia.co.uk -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
