At 14:54 -0500 6/13/02, Gerald Clark wrote: >CREATE TABLE X (FLD1 INT PRIMARY KEY); >or >CREATE TABLE X (FLD1 INT, UNIQUE(FLD1)); > >UNIQUE applies to an index, not a field.
That latter statement is equivalent to the one he used. The problem is that the column isn't declared NOT NULL. Your PRIMARY KEY declaration would result in the intended effect, too, because it automatically causes the column to be declared NOT NULL. > > > >Andy Sy wrote: > >>----- Original Message ----- From: "Paul DuBois" <[EMAIL PROTECTED]> >>To: "Andy Sy" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> >>Sent: Friday, June 14, 2002 2:45 AM >>Subject: Re: Why does Key==Mul in DESCRIBE TABLE for unique key? >> >>>At 2:03 +0800 6/14/02, Andy Sy wrote: >>> >>>>mysql> CREATE TABLE X (FLD1 INT UNIQUE); >>>>Query OK, 0 rows affected (0.05 sec) >>>> >>>>mysql> DESCRIBE X; >>>>+-------+---------+------+-----+---------+-------+ >>>>| Field | Type | Null | Key | Default | Extra | >>>>+-------+---------+------+-----+---------+-------+ >>>>| FLD1 | int(11) | YES | MUL | NULL | | >>>>+-------+---------+------+-----+---------+-------+ >>>> >>>>Doesn't MUL mean a key can exist multiple times >>>>in the index? >>>> >>>Right. It means it's part of a non-unique index. >>> >> >>But I declared the field as UNIQUE (see the CREATE >>TABLE statement). >> >> >> >>--------------------------------------------------------------------- >>Before posting, please check: >> http://www.mysql.com/manual.php (the manual) >> http://lists.mysql.com/ (the list archive) >> >>To request this thread, e-mail <[EMAIL PROTECTED]> >>To unsubscribe, e-mail >><[EMAIL PROTECTED]> >>Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php >> > > > >--------------------------------------------------------------------- >Before posting, please check: > http://www.mysql.com/manual.php (the manual) > http://lists.mysql.com/ (the list archive) > >To request this thread, e-mail <[EMAIL PROTECTED]> >To unsubscribe, e-mail <[EMAIL PROTECTED]> >Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
