Hello john,
Thursday, March 08, 2001, 12:19:22 AM, you wrote:
jrd> with MySQL 3.23.33 on Linux, shouldn't UNIQUE columns that contain NULL
jrd> values still reject rows that are the same? this isn't working (it allows
jrd> duplicate rows to be included if one of the columns is NULL). this seems wrong.
No, this is absolutely correct and any database system should act like
this. NULL means no that conetn is not specified, it is not '0' or
empty string. If you compare NULL value to NULL value then (NULL=NULL)
is not TRUE, but also NULL. If you specified column as NULL that only
means it can't contain same values, but NULL is no value so you can
have many records with NULL entries in column.
And you can always set NOT NULL too...
--
Best regards,
Rimantas mailto:[EMAIL PROTECTED]
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