Want to protect your cyber security and still get fast solutions? Ask a secure question today.Go Premium

x
?
Solved

[PHP][MYSQL]Get highest value

Posted on 2009-05-04
3
Medium Priority
?
570 Views
Last Modified: 2012-05-06
In PHP I have a table with rows. The rows are currently within a SQL database and are stored by a value call position in which the will be loaded with ORDER BY ASC(position).
What I am having trouble doing is finding the row with the highest value of position WHERE parentseries='$parent' AND category='$category'

I need to do this when I am  adding a new variable. In a sort it's an auto increment of my own. But I cannot use normal auto Increment as this table is shared with other product tables.

example of table:
parentseries    |    category    |    data    |    position
1721                  14                      ...            1
1721                  14                      ...            2
1532                  14                      ...            1
1532                  14                      ...            2

What now want to happen is if I add another category 14 item that it will find all other category 14 items that are parentseries 1721 and find which one has the highest position integer.

Thank you.
0
Comment
Question by:drakeshe
  • 2
3 Comments
 
LVL 11

Accepted Solution

by:
jausions earned 2000 total points
ID: 24300490
SELECT MAX(position) FROM myTable WHERE parentseries='$parent' AND category='$category'

You also want to make sure you're using a database engine that support transactions (InnoDB for instance) otherwise there's a slight chance you could run the same query at exactly the same moment and then insert the same "position" twice for different record. That of course would depend on the traffic on your database and how often you do this kind of INSERT
0
 
LVL 5

Author Closing Comment

by:drakeshe
ID: 31577818
Thank you! This worked perfectly! Exactly what I needed
0
 
LVL 5

Author Comment

by:drakeshe
ID: 24300537
Thank you! It worked perfectly! Exactly what I needed
0

Featured Post

What does it mean to be "Always On"?

Is your cloud always on? With an Always On cloud you won't have to worry about downtime for maintenance or software application code updates, ensuring that your bottom line isn't affected.

Question has a verified solution.

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

There are times when I have encountered the need to decompress a response from a PHP request. This is how it's done, but you must have control of the request and you can set the Accept-Encoding header.
In this article, I’ll talk about multi-threaded slave statistics printed in MySQL error log file.
In this seventh video of the Xpdf series, we discuss and demonstrate the PDFfonts utility, which lists all the fonts used in a PDF file. It does this via a command line interface, making it suitable for use in programs, scripts, batch files — any pl…
Video by: Mark
This lesson goes over how to construct ordered and unordered lists and how to create hyperlinks.
Suggested Courses

580 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