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

x
?
Solved

Why is this SQL (mySQL) stalling?

Posted on 2013-06-12
2
Medium Priority
?
400 Views
Last Modified: 2013-07-03
Hello experts,

I have a SQL statement I'm running in mySQL and it is stalling. I've narrowed it down to the NOT EXISTS subquery. Can you help me figure out what went wrong?

I'm trying to get data from piewarehouse filtered for pieIDs that were not refilled that day.

Thank you!

SELECT * FROM piewarehouse PW 
inner join toiletpaper TP on TP.tpid = PW.pieid 
where TP.rolltype in ('long', 'short', 'sheet')
and (not exists (select 1 from piewarehouse PW2 where PW2.pieID = PW.pieid and PW2.daterefilled = '2013-06-12')) 

Open in new window

0
Comment
Question by:EffinGood
2 Comments
 
LVL 60

Accepted Solution

by:
Kevin Cross earned 2000 total points
ID: 39242399
Hi.

Are there really multiple records per pieID? If not, then this is simpler, right?

SELECT * /* I would spell out actual columns here versus using wildcard. */
FROM piewarehouse PW 
INNER JOIN toiletpaper TP ON TP.tpid = PW.pieid 
WHERE TP.rolltype in ('long', 'short', 'sheet')
AND PW.daterefilled <> '2013-06-12'
;

Open in new window


I would probably still add the other filter on date.
SELECT * /* I would spell out actual columns here versus using wildcard. */
FROM piewarehouse PW 
INNER JOIN toiletpaper TP ON TP.tpid = PW.pieid 
WHERE TP.rolltype in ('long', 'short', 'sheet')
AND PW.daterefilled <> '2013-06-12'
AND NOT EXISTS (
    SELECT 1
    FROM piewarehouse PW2
    WHERE PW2.pieID = PW.pieID
    AND PW2.daterefilled = '2013-06-12'
)
;

Open in new window


If it continues to give problems, open MySQL Workbench and run the query with EXPLAIN in front. One issue may be there is no index on pieID, daterefilled, or both.
0
 
LVL 111

Expert Comment

by:Ray Paseur
ID: 39242787
If you have not already done so, you might want to read the article here:
http://www.experts-exchange.com/Database/MySQL/A_1250-3-Ways-to-Speed-Up-MySQL.html
0

Featured Post

Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

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

In this series, we will discuss common questions received as a database Solutions Engineer at Percona. In this role, we speak with a wide array of MySQL and MongoDB users responsible for both extremely large and complex environments to smaller singl…
It’s a season to be thankful, and we’re thankful for users like you who engage on site, solve technology problems, and network with others in the industry. What tech are we most thankful for? Keep reading.
The viewer will learn how to look for a specific file type in a local or remote server directory using PHP.
The viewer will learn how to create and use a small PHP class to apply a watermark to an image. This video shows the viewer the setup for the PHP watermark as well as important coding language. Continue to Part 2 to learn the core code used in creat…
Suggested Courses

772 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