Syntax of SQL query in PHP code

Sorry, this is probably something that falls between PHP and mySQL, so apologies if this is in the wrong section.

I am using a bit of code that autocompletes a field when someone types:

$rs = mysql_query(‘select Lodge from lodges Lodge like "%’. mysql_real_escape_string($_REQUEST[‘term’]) .‘%" order by Lodge asc limit 0,50’, $dblink);

Which works great, and looks up all the records in the table lodges.

But I’d like it to filter on a particular field, and can’t get it to work - basically just need to add something like the following to filter out records where a particular field is not blank:

select Lodge from lodges WHERE field name <> ‘’ AND lodges like…

This must be an easy one, but I can’t seem to get the syntax.


Please be aware that the mysql_* extension is now deprecated as of the current version of PHP and will very likely be removed from the next 5.x version and will likely not be in PHP 6.x (when it eventually is released). You should migrate over to either the mysqli_* extension or to PDO. PDO is a better choice as it doesn’t tie you down so much to a particular database server software.

Once you have migrated you should use Prepared Statements to prevent SQL Injection attacks. Have a read of this article from the PHP manual, it shows how to use prepared statements with PDO and also explains the principle.

Is the field NULL or contains an empty string?

If it’s null, you should use:


Or check if it’s not null AND check if it’s not empty:

WHERE (name IS NOT NULL AND name <> '')

Like SpacePhoenix said, you should migrate to mysqli_ or PDO.
Except if you’re just trying out stuff and not planning on putting your website/web app available to the Internet.

If you’re going to put it live on the net:
If you’re trying out stuff and not planning on changing your DB server (mySQL for something else), then change it with mysqli_, it will be easier.

I wrote an article on my blog about the difference between mysql_ and mysqli_ if you’re interested. The main reason to migrate is because of SQL injections (a security hole).

PDO is more preferable to mysqli_* as it makes the code more portable, if you were to ever change database server software (you can’t ever be 100% certain that you’ll always stick with MySQL), then all that would need changing would be the details for connecting to the database and any MySQL specific SQL

Thanks guys.

SpacePhoenix: If he’s a beginner trying stuff out, why would he care? And with my 10+ years of experience on more than 100 projects, we never, ever, had to change the database. So lets agree do disagree then :wink:

P.S. A place that using an ORM make sense is with “products” that you sell/share, IMO. It just depends on the context.

Agree with xMog , in 15 years as a developer I’ve never had to change a database.

I have had the pleasure of adding in new databases to support several times though never in php. Not fun. Having a generic connection object such as pdo is only a tiny part of the battle. All databases have enough quirks that it becomes a pain to back fit one.

Having said that, the reason for using pdo by default is that it supports named parameters. Makes the code easier to develop and support. This one capability trumps any perceived advantage of using native interfaces.