Hi !
Johan De Meersman wrote: > In SQL, the correct syntax is "IS NULL" or "IS NOT NULL". > > Random programming languages more often than not have no decent support for > NULL content, although your DB library might have an isnull() function or > something similar. Once you've exported a field into a regular variable, > however, most often NULL becomes indistinguishable from an emtpy string. That is what "embedded SQL" has "indicator variables" for: When you select (rather: "fetch") database values into host language (say, C, Cobol, Pascal, ...) variables, you have two to receive them: - The host variable for the real value, - and an indicator variable (typically, int). The indicator would be set to -1 for a NULL value, and it might use positive values to denote strings lengths, truncations, or similar things. Jörg -- Joerg Bruehe, MySQL Build Team, joerg.bru...@sun.com Sun Microsystems GmbH, Sonnenallee 1, D-85551 Kirchheim-Heimstetten Geschaeftsfuehrer: Thomas Schroeder, Wolfgang Engels, Dr. Roland Boemer Vorsitzender des Aufsichtsrates: Martin Haering Muenchen: HRB161028 -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql?unsub=arch...@jab.org
