?
Solved

Check if column exists in mysql table with php

Posted on 2012-04-10
6
Medium Priority
?
2,441 Views
Last Modified: 2012-04-10
Hi Experts!

As in title, I need a php script checking if column exists in table.

Thanks for any help.
0
Comment
Question by:Zado
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 4
  • 2
6 Comments
 
LVL 35

Expert Comment

by:gr8gonzo
ID: 37828526
The "information_schema" table in MySQL is a special, internal table that holds all the information about the database structure. You can query it like this:

SELECT column_name FROM information_schema.columns WHERE table_name = 'my_table'

You can use that method / query to check for column existence.
0
 
LVL 8

Author Comment

by:Zado
ID: 37828623
Thanks gr8gonzo, I wrote this:
$checkcolumn = mysql_query("SELECT $column FROM information_schema.columns WHERE table_name = '$tablename'");
if (mysql_num_rows($checkcolumn)>0) {echo "column does not exists!";} else {echo "column exists!";}

Open in new window

but it doesn't work as expected, I keep trying...
0
 
LVL 8

Author Comment

by:Zado
ID: 37828685
Ok, got it, it's probably not the best to do it, but it works, if you know better way, please let me know:

$tablename = $_GET['table'];
		$column = "UserID";
		
		$columnlist = array();
		$checkcolumn = mysql_query("SELECT column_name FROM information_schema.columns WHERE table_name = '$tablename'");
		while ($row = mysql_fetch_array($checkcolumn)) {
			$columnlist[] = $row['column_name'];
		}
		$columnlist = implode(',',$columnlist);
		if (strpos($columnlist,$column)!==false) {echo "column exists!";} else {echo "column does not exists!";}

Open in new window

0
Video: Liquid Web Managed WordPress Comparisons

If you run run a WordPress, you understand the potential headaches you may face when updating your plugins and themes. Do you choose to update on the fly and risk taking down your site; or do you set up a staging, keep it in sync with your live site and use that to test updates?

 
LVL 8

Author Comment

by:Zado
ID: 37828692
*up  'it's probably not the best way to do it'
0
 
LVL 35

Accepted Solution

by:
gr8gonzo earned 2000 total points
ID: 37828697
Sorry, try this:

$checkcolumn = mysql_query("SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME='{$tablename}' AND COLUMN_NAME = '{$column}';");
if (mysql_num_rows($checkcolumn)>0) {echo "column does not exists!";} else {echo "column exists!";}

Open in new window

0
 
LVL 8

Author Closing Comment

by:Zado
ID: 37828829
Thanks :-)
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

This post looks at MongoDB and MySQL, and covers high-level MongoDB strengths, weaknesses, features, and uses from the perspective of an SQL user.
By, Vadim Tkachenko. In this article we’ll look at ClickHouse on its one year anniversary.
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 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…
Suggested Courses

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