On Fri, Mar 2, 2012 at 13:59, Jay A. Kreibich <j...@kreibi.ch> wrote: > On Fri, Mar 02, 2012 at 10:44:20AM +0100, Christoph P.U. Kukulies > scratched on the wall: > > Kind of. It implies uniqueness in the SQL sense, which does not > include NULLs (remember, NULL != NULL).
Actually, NULL != NULL is unknown. Any expression compared to NULL with any of the operators == != < > <= >= LIKE GLOB will have unknown result. C:\> sqlite3 SQLite version 3.7.10 2012-01-16 13:28:40 Enter ".help" for instructions Enter SQL statements terminated with a ";" sqlite> SELECT CASE WHEN NULL = NULL THEN 0 ...> WHEN NULL <> NULL THEN 1 ...> ELSE 2 ...> END; 2 sqlite> .q -- Benoit Mortgat _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users