I've wrote a query to check for users with certain criteria, one being they have an email address.
Our site will allow a user to have or not have an email address.
$aUsers=$this->readToArray(' SELECT `userID` FROM `users` WHERE `userID` IN(SELECT `userID` FROM `users_indvSettings` WHERE `indvSettingID`=5 AND `optionID`='.$time.') AND `email`!="" ');
Is this the best way to check for an empty field in SQL? I've just tried "IS NOT NULL" and this still returned a users record without them having an email address.
The query above works but out of curiosity I wondered if I'm doing it the correct way.
An empty field can be either an empty string or a
To handle both, use:
email > ''
which can benefit from the
range access if you have lots of empty email record (both types) in your table.