List:General Discussion« Previous MessageNext Message »
From:Paul DuBois Date:July 29 1999 7:24pm
Subject:Re: NULL values?
View as plain text  
At 12:01 PM -0700 7/29/99, Nathan Clegg wrote:
>I'm having a little trouble with NULL values.  Can anyone explain this:
>
>mysql> describe test;
>+--------------+---------------------+------+-----+---------+
>| Field        | Type                | Null | Key | Default |
>+--------------+---------------------+------+-----+---------+
>| name         | varchar(15)         | YES  |     | NULL    |
>| email        | varchar(25)         | YES  |     | NULL    |
>| phone_number | int(11)             | YES  |     | NULL    |
>| id           | int(11)             |      | PRI | 0       |
>| a            | enum('one','two')   | YES  |     | NULL    |
>+--------------+---------------------+------+-----+---------+
>5 rows in set (0.01 sec)
>
>mysql> insert into test values (NULL, NULL, NULL, 9, NULL);
>mysql> insert into test values ('NULL', 'NULL', 'NULL', 10, 'NULL');
>
>mysql> select * from test where name='NULL';
>+------+-------+--------------+----+------+
>| name | email | phone_number | id | a    |
>+------+-------+--------------+----+------+
>| NULL | NULL  |            0 | 10 |      |
>+------+-------+--------------+----+------+
>1 row in set (0.00 sec)
>
>mysql> select * from test where name=NULL;
>Empty set (0.00 sec)
>
>How can I select on NULL fields?


http://www.mysql.com/Manual_chapter/manual_Problems.html#Problems_with_NULL

-- 
Paul DuBois, paul@stripped
Thread
NULL values?Nathan Clegg29 Jul
  • Re: NULL values?Martin Ramsch29 Jul
  • Re: NULL values?Paul DuBois29 Jul
  • Re: NULL values?Ralph Graulich30 Jul