Go Premium for a chance to win a PS4. Enter to Win

x
?
Solved

Need help with a MySQL Query

Posted on 2011-02-19
3
Medium Priority
?
439 Views
Last Modified: 2012-06-21
Hi,

in my Database I have a table called images. There I have two important columns: id and org_image_id. If a user modify an "original" image, the modified image is stored in the same table but with org_image_id = id of the original image.

What I want to do is to remove all modified images from the database, if there are no original image in the database. I wrote this query, but it does not work for me:

[SQL] delete FROM images WHERE org_image_id NOT IN(SELECT DISTINCT id FROM images WHERE org_image_id is NULL)and LRU < DATE_SUB(NOW(), INTERVAL 30 DAY);
[Err] 1093 - You can't specify target table 'images' for update in FROM clause

Open in new window


Can someone help me please?
0
Comment
Question by:LL0rd
  • 2
3 Comments
 
LVL 26

Assisted Solution

by:tigin44
tigin44 earned 200 total points
ID: 34936080
As I understand this is not the whole query...This one relates to another.. if so could you provide the whole set...

delete FROM images
WHERE org_image_id NOT IN(SELECT DISTINCT id FROM images WHERE org_image_id is NULL)
     and LRU < DATE_SUB(NOW(), INTERVAL 30 DAY);
0
 
LVL 8

Accepted Solution

by:
wolfgang_93 earned 1800 total points
ID: 34936094
Try something like this (note: the temporary table automatically is dropped at the end of
the user session):

CREATE TEMPORARY TABLE idlist (id INTEGER);
INSERT INTO idlist(id) SELECT DISTINCT id FROM images WHERE org_image_id IS NULL and LRU < DATE_SUB(NOW(), INTERVAL 30 DAY);
delete FROM images WHERE org_image_id NOT IN (select id from idlist);
0
 
LVL 26

Expert Comment

by:tigin44
ID: 34936096
also you can try this

DELETE I
FROM images I
      LEFT OUTER JOIN images D ON I.org_image_id = D.id
WHERE D.id IS NULL
  AND D.org_image_id is NULL
 AND I.LRU < DATE_SUB(NOW(), INTERVAL 30 DAY);
0

Featured Post

Keep up with what's happening at Experts Exchange!

Sign up to receive Decoded, a new monthly digest with product updates, feature release info, continuing education opportunities, and more.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

In this blog, we’ll look at how improvements to Percona XtraDB Cluster improved IST performance.
Instead of error trapping or hard-coding for non-updateable fields when using QODBC, let VBA automatically disable them when forms open. This way, users can view but not change the data. Part 1 explained how to use schema tables to do this. Part 2 h…
In this video, Percona Solution Engineer Rick Golba discuss how (and why) you implement high availability in a database environment. To discuss how Percona Consulting can help with your design and architecture needs for your database and infrastr…
This lesson discusses how to use a Mainform + Subforms in Microsoft Access to find and enter data for payments on orders. The sample data comes from a custom shop that builds and sells movable storage structures that are delivered to your property. …
Suggested Courses

916 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question