Re: Interesting query outcomes

On Tuesday, August 18, 2020 at 5:34:12 PM UTC-5, Lyle H. Gray wrote:
> I am unable to duplicate this effect. 
> 
> What is the full structure of your table, and what version of MySQL are you 
> using? 

UNIX> mysql --version
Ver 14.14 Distrib 5.6.45, for Linux (x86_64) using  EditLine wrapper

MYSQL> desc jcrosstbl;
| Field          | Type         | Null | Key | Default | Extra                       |
+----------------+--------------+------+-----+---------+-----------------------------+
| gn_ID          | varchar(12)  | NO   | PRI |         |                             |
| TNAM           | varchar(96)  | YES  |     | NULL    |                             |
| Descrptn       | varchar(512) | YES  |     | NULL    |                             |
| created        | datetime     | YES  |     | NULL    |                             |
| updated        | datetime     | YES  |     | NULL    | on update CURRENT_TIMESTAMP |
| status         | int(1)       | YES  |     | NULL    |

It also duplicates when I port the table to an older server where MySQL is
Ver 14.12 Distrib 5.0.95, for redhat-linux-gnu (x86_64) using readline 5.1.

If I do
mysql> update jcrosstbl set TNAM=NULL where TNAM='';
the duplicates get combined.

joe