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

x
?
Solved

MYSQL: How to combine two queries

Posted on 2013-01-10
3
Medium Priority
?
620 Views
Last Modified: 2013-01-11
Dear Experts.

I have two tables.

Table 1 has the following columns.

id
host
count

The following query sets the count field to 3 where the host is microsoft.com

UPDATE hosts SET `count` =  '3' WHERE  hosts.host = "microsoft.com";  

Open in new window


Table 2 has the following columns.

id
host
company_emails
sent

This query provides a list of hosts with the corresponding count of emails sent

SELECT `host` , COUNT( * ) AS total FROM  `company_emails` WHERE `sent` = 1 GROUP BY host ORDER BY COUNT( * ) DESC;

Open in new window


How would I combine the two queries so that hosts.count field contains the "total" value calculated in the second query?

Many thanks.
0
Comment
Question by:AdrianSmithUK
  • 2
3 Comments
 
LVL 12

Accepted Solution

by:
jessegivy earned 2000 total points
ID: 38765279
Maybe this?

UPDATE
hosts,
(SELECT host, COUNT( * ) as total FROM  `company_emails` WHERE `sent` = 1 GROUP BY host) as emails
SET hosts.`count` =  emails.total WHERE  hosts.host = email.host;
0
 

Author Closing Comment

by:AdrianSmithUK
ID: 38766326
Almost perfect. A small typo (email.host) should read emails.host.

You're a star!

Many thanks.
Adrian
0
 

Author Comment

by:AdrianSmithUK
ID: 38766329
Final solution: (in case I need to cut and paste it at some time)

UPDATE HOSTS ,
(
SELECT host, COUNT( * ) AS total
FROM  `company_emails` 
WHERE  `sent` =1
GROUP BY host
) AS emails
SET hosts.`count` = emails.total WHERE hosts.host = emails.host

Open in new window

0

Featured Post

NEW Veeam Agent for Microsoft Windows

Backup and recover physical and cloud-based servers and workstations, as well as endpoint devices that belong to remote users. Avoid downtime and data loss quickly and easily for Windows-based physical or public cloud-based workloads!

Question has a verified solution.

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

In this article, I’ll talk about multi-threaded slave statistics printed in MySQL error log file.
Creating a Cordova application which allow user to save to/load from his Dropbox account the application database.
Learn how to match and substitute tagged data using PHP regular expressions. Demonstrated on Windows 7, but also applies to other operating systems. Demonstrated technique applies to PHP (all versions) and Firefox, but very similar techniques will w…
In this video, Percona Solutions Engineer Barrett Chambers discusses some of the basic syntax differences between MySQL and MongoDB. To learn more check out our webinar on MongoDB administration for MySQL DBA: https://www.percona.com/resources/we…
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