Re: Comparing multiple Mysql tables to find duplicates
| From: | John W. Holmes | Date: | Fri, 30 Jan 2004 17:48:53 +0000 |
| Subject: | Re: Comparing multiple Mysql tables to find duplicates | ||
| References: | 1 | Groups: | php.general |
| Request: | Send a blank email to php-general+get-176370@lists.php.net to get a copy of this message | ||
From: "Chris Bruce" <chris@idextrus.com>
> I am trying to write a function that would compare one table to a
> number of other tables in Mysql and remove any duplicates found. This
> is for tables of email addresses where I want to remove any dups found.
>
> Example:
> Master list - compare to list1, list2, list3, and so on and remove
> matches found from list1, list2, list3 etc. *not* from Master list.
>
> Does anyone know of any such beast before I set out to reinvent it?
DELETE FROM list1 USING master_list, list1 WHERE list1.email =
master_list.email
Repeat for other tables.
---John Holmes...