Richard Skelton wrote:
>
> Hi,
> How do I find duplicate entrys in a column.
> In the table below I know I have duplicate entries in dwg_no how do I find/list
> them?
>
> mysql> show columns from drawing;
> +-------------------+--------------+------+-----+---------+-------+
> | Field | Type | Null | Key | Default | Extra |
> +-------------------+--------------+------+-----+---------+-------+
> | dwg_no | char(8) | YES | | NULL | |
> | speci | char(60) | YES | | NULL | |
> | tfdn | char(8) | YES | | NULL | |
> | title | char(80) | YES | | NULL | |
> | plant | char(25) | YES | | NULL | |
> | drawn | char(8) | YES | | NULL | |
> | sub_con | char(10) | YES | | NULL | |
> | project | char(20) | YES | | NULL | |
> | site | char(20) | YES | | NULL | |
> | rig | char(20) | YES | | NULL | |
> | date | char(10) | YES | | NULL | |
> | remarks | char(30) | YES | | NULL | |
> | prefix | char(7) | YES | | NULL | |
> | issue | char(7) | YES | | NULL | |
> | micro | char(4) | YES | | NULL | |
> | scanned | char(3) | YES | | NULL | |
> | modification_time | char(30) | YES | | NULL | |
> | who_modified | char(10) | YES | | NULL | |
> | group_modified | char(10) | YES | | NULL | |
> | db_id | smallint(10) | YES | | NULL | |
> +-------------------+--------------+------+-----+---------+-------+
> 20 rows in set (0.20 sec)
>
> --
> Cheers
> Richard.
> =
> Richard Skelton | e-mail : Richard.Skelton@stripped
select dwg_no, count(*) as n from drawing group by dwg_bo having n > 1;
will list all dwg_no values that are duplicated.
--
Sasha Pachev
http://www.sashanet.com
