Re: Does NULL == ""?

[Paul DuBois]

At 11:00 AM -0400 9/15/03, Randy Chrismon wrote:
>The MySQL documentation confuses me a bit. If I create a table with
>property NOT NULL and default "", does that mean that a record with a
>column so defined will have a zero-length string in that column if I
>don't provide a value? I guess what I'm asking is whether there's a
>difference between a field with NULL in it and a field with a
>zero-length ("") string in it.

Other responses have given a lot of informatin that I'll not repeat here,
but you can test whether the two values are equal like this:

mysql> SELECT "" IS NULL;
+------------+
| "" IS NULL |
+------------+
|          0 |
+------------+

Guess not. :-)

>
>Thanks.
>
>Randy


-- 
Paul DuBois, Senior Technical Writer
Madison, Wisconsin, USA
MySQL AB, www.mysql.com

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