Ye, NULL = "Undefined" in every database I've ever used.
Null and "" are not equal, NULL and NULL are not equal eigther. Infact absolutly nothing is ever equal to NULL.
One slight exception is that for purposes of ORDER BY, GROUP BY, and DISTINCT, NULL values are considered the same in the sense that they group together. (It's difficult to see what other way of handling them would make sense for such operations.)
Haydies. Database/PHP Developer
----- Original Message ----- From: "Paul DuBois" <[EMAIL PROTECTED]> To: "Martin Gainty" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]> Sent: Monday, September 15, 2003 5:02 PM Subject: Re: NULL
: At 11:12 AM -0400 9/15/03, Martin Gainty wrote: : >Randy- : > : >NULL means No Data : >So in the case of a MySQL Column defined as Type String : >NULL is equivalent to "" : : Actually, it's not. : : "" isn't No Data, it's Data with a length of zero. : : -- : Paul DuBois, Senior Technical Writer
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