From: Mike Machado
Date: March 12 1999 7:00am
Subject: MySQL and NULL entires
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I did an alter table to add a column called billgroup as an int(10)



This worked ok and it set all the existing rows to have "NULL" in the
new column. So I figured I would do a mass update to switch it then to
"1".  These are the statements I executed but did not seem to change
anything:

select billgroup from account limit 10;

+-----------+
| billgroup |
+-----------+
|      NULL |
|      NULL |
|      NULL |
|      NULL |
|      NULL |
|      NULL |
|      NULL |
|      NULL |
|      NULL |
|      NULL |
+-----------+
10 rows in set (0.01 sec)


update account set billgroup = "1" where billgroup = "NULL";
update account set billgroup = "1" where billgroup = NULL;
update account set billgroup = "1" where billgroup = "";
update account set billgroup = "1" where billgroup = '';
update account set billgroup = "1" where billgroup = "0";

select billgroup from account limit 10;
+-----------+
| billgroup |
+-----------+
|      NULL |
|      NULL |
|      NULL |
|      NULL |
|      NULL |
|      NULL |
|      NULL |
|      NULL |
|      NULL |
|      NULL |
+-----------+
10 rows in set (0.01 sec)

?

What is the where clause I have to use to match the data in the columns
after an alter table?

MySQL 3.22.13 - Linux 2.0.36 libc5

--
Mike Machado
mike@stripped
InnerCite
Network Specialist