Solved

Dynamic Column Names

Posted on 2013-12-03
6
251 Views
Last Modified: 2013-12-17
I'm building a PHP script that will run monthly, to gather data from different tables and bring it into a new table.

As it stands right now, I am dropping the tables monthly, and re-creating them in this script.  The column names consist of the month name and year, and therefore will change monthly.

For example, the table I'm working in right now has a column for november12, december12, january12, all the way through december13.

I need to extract the data from the columns in order to calculate averages, and more importantly, display the data on the page.

My question is how to structure my SELECT query based on these dynamic column names, and then how to put them into variables to display on the page in my WHILE loop?

Here is how I am naming the columns.

#Get Months between last month and 12 months ago
function getAllMonths($date1, $date2)
	{
	$time1 = strtotime($date1);
	$time2 = strtotime($date2);
	$my = date('mY', $time2);
   
	$months = array(date('Y-m', $time1));
   
	while($time1 < $time2) 
		{
		$time1 = strtotime(date('Y-m-d', $time1).' +1 month');
		if(date('mY', $time1) != $my && ($time1 < $time2))
		$months[] = date('Y-m', $time1);
		}
   
	$months[] = date('Y-m', $time2);
	$months = array_unique($months);
	return $months;
	}

#Define Months to use
$thisMonth = date("Y-m", strtotime($today));
$yearAgo = date("Y-m", strtotime("-1 year", strtotime($thisMonth)));
$allMonths = getAllMonths($yearAgo, $thisMonth);

#Build the quality calls table!
$crt = "CREATE TABLE IF NOT EXISTS `repanalysis_qualitycalls`
			(
			`id` int(20) NOT NULL auto_increment,
			`respid` int(6) NOT NULL,";
			
foreach($allMonths AS $monthRange)
	{
	$monthNames = date("Fy", strtotime($monthRange));
	$crt .= '`'.$monthNames.'` decimal(7,2) default 0,';
	}
			
$crt .= "`averageqc` decimal (15,2),
			`avgtogoal` decimal (15,5),
			`qc_regionalrank` int(10),
			`qc_overallrank` int(10),
			 PRIMARY KEY  (`id`),
			 KEY `respid` (`respid`)
			) 
			ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=0";
$result = mysql_query($crt) or die("Cannot create quality calls table: " . mysql_error());

Open in new window


I tried doing a select * but I'm not sure how to get the column names out of that query:

	//Extract Quality Calls for Calculations.
	$getQC = mysql_query("SELECT * FROM repanalysis_qualitycalls") or die("Cannot pull quality calls: " . mysql_error());

	if(mysql_num_rows($getQC) > 0)
		{
		while($row = mysql_fetch_assoc($getQC))
			{
			$repId = $row['respid'];
			}
		}
	}

Open in new window

0
Comment
Question by:t3chguy
6 Comments
 
LVL 34

Expert Comment

by:gr8gonzo
ID: 39693468
You can either run a DESCRIBE <table> query to get the table structure, or as long as you have a record, you can just look at the keys of any record that is returned with mysql_fetch_assoc().

By the way, mysql_ functions are deprecated, so you may want to consider moving to the newer mysqli functions.
0
 
LVL 34

Expert Comment

by:gr8gonzo
ID: 39693469
0
 
LVL 1

Author Comment

by:t3chguy
ID: 39693482
How can I use the key from the mysql_fetch_assoc?
0
Efficient way to get backups off site to Azure

This user guide provides instructions on how to deploy and configure both a StoneFly Scale Out NAS Enterprise Cloud Drive virtual machine and Veeam Cloud Connect in the Microsoft Azure Cloud.

 
LVL 34

Accepted Solution

by:
gr8gonzo earned 500 total points
ID: 39693541
Use array_keys:

http://us3.php.net/array_keys

if(mysql_num_rows($getQC) > 0)
		{
		while($row = mysql_fetch_assoc($getQC))
			{
			$repId = $row['respid'];
                        $columns = array_keys($row); // <<<<<<<<<<<<<<<<<<<<<<
			}
		}
	}

Open in new window

0
 
LVL 27

Expert Comment

by:yodercm
ID: 39693707
Try mysql_list_fields() to get field names

http://us2.php.net/manual/en/function.mysql-list-fields.php
(deprecated but still works beautifully)


 or mysql_query() to issue an SQL SHOW COLUMNS FROM table [LIKE 'name']

http://dev.mysql.com/doc/refman/5.0/en/show-columns.html
0
 
LVL 109

Expert Comment

by:Ray Paseur
ID: 39693720
You probably want to define DATE columns as data type DATE.  Then you can use the standard ways of getting the data.  There is a little more about how to handle DATE and DATETIME information in this article.
http://www.experts-exchange.com/Web_Development/Web_Languages-Standards/PHP/A_201-Handling-date-and-time-in-PHP-and-MySQL.html

That said, I would expect that it might make sense to have the date values in a single column in each of the rows instead of in columns for each date.  One example of why that might be an advantageous design would emerge if the boss comes in and says, "Give me the last two years data."  If the dates are in one column you just change the query.  If the dates are in columns by month, you have to rewrite your script.
0

Featured Post

PRTG Network Monitor: Intuitive Network Monitoring

Network Monitoring is essential to ensure that computer systems and network devices are running. Use PRTG to monitor LANs, servers, websites, applications and devices, bandwidth, virtual environments, remote systems, IoT, and many more. PRTG is easy to set up & use.

Question has a verified solution.

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

Introduction HTML checkboxes provide the perfect way for a web developer to receive client input when the client's options might be none, one or many.  But the PHP code for processing the checkboxes can be confusing at first.  What if a checkbox is…
I imagine that there are some, like me, who require a way of getting currency exchange rates for implementation in web project from time to time, so I thought I would share a solution that I have developed for this purpose. It turns out that Yaho…
The viewer will learn how to dynamically set the form action using jQuery.
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…

777 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