On 25/05/16 22:42, Fleshgrinder wrote: > It is not the same as null, very similar, but definitely not the same. > Think of it in DB terms: > > | table | > | ----- | > | id | > > SELECT name FROM table; > > That's not null, it's not defined (undefined, unset, ...). In other > words, null is a value and undefined/unset a state.
If no field 'name' exists then you get an error. If no valid record is found then name will be populated with 'NULL' if you try and read the returned record ... unless the 'noofrec' variable is accessed first and establishes that '0' records were returned. If you are reading a set of fields for which some have no matching values then these are returned as 'NULL' while the rest will be populated. NULL is ALWAYS a 'state' meaning that this field is undefined or more accurately unset. -- 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
