WP_Query is a PHP class in the WordPress codebase.
Understanding WP_Query is essential in learning WordPress development. The command lets you retrieve particular data from the database using several parameters like author, date, and tag, to name a few.
Let’s say you want to customize the front end of your webpage, so it displays posts tagged as ‘featured’ only. Here’s what the query for this task looks like:
$query = new WP_Query( array( 'tag' => 'featured' ) );
Read on to get a better understanding of the use of WP_Query in WordPress and its benefits.
WP_Query and the Loop
To display posts, WordPress uses a built-in code called the loop. It retrieves content from the database and presents it according to your theme’s instructions.
With WP_Query, you can take control of what posts the loop will output.
Here is what an empty skeleton of a loop looks like:
if (have_posts()){
while (have_posts()):the_post(){
// output content however we please here
}
}
What you want to display happens within the ‘while’ statement. This code gets repeated once for each post. It gives you complete control over how to format or output posts.
Within the ‘while’ statement, you can include any combination of PHP and HTML. This way, you can manually choose to display a specific content based on the stated parameter.
By default, the URL of the page you access determines which loop it initializes.
If you access your monthly archives, then WordPress will run the loop with the date as the parameter to retrieve posts from the stated month. The same process also applies to other parameters.
If you want to query posts on your webpage, however, you can’t depend on the URL. Thus, WP_Query comes into play.
Let’s say you want to add a customized list of content on the homepage, displaying the two most recent posts from the ‘featured’ category name.
Here’s the query you put on the front-page.php file:
if ($featuredposts->have_posts()){
// looping over the $featuredposts:
while ($featuredposts->have_posts()) {
$featuredposts->the_post();
// the content you need would go here
}
}
What are the Benefits of WP_Query?
WP_Query is beneficial for developing WordPress themes. You can customize its design by choosing content to display in detail.
Additionally, it gives you the ability to create custom loops to display custom pages instead of relying solely on get_posts() and get_pages() to retrieve posts and pages. For example, you can create a WordPress webpage showcasing certain categories only.
Since the query is an object, you can use it to output any property of the posts’ content.
All in all, WP_Query is a powerful PHP class that gives you a lot of flexibility in customizing your theme and querying custom content.
Some Caveats when Using WP_Query
Despite its benefits, be mindful that overloading your webpage with too many queries might lead to server overload. Complex queries require a lot of RAM from your server resource, which can slow your page load speed.
If all you need is to change how a WordPress page display posts in a particular archive, you can create a template file and modify the loop accordingly.
To modify the current query, consider using the pre_get_posts hook instead. Your webpage will run it first before initializing the query, saving you time and resources from having to create a new query variable object with WP_Query.
Conclusion
WP_Query is a PHP class in WordPress that developers use for page optimization and theme building. While it may cost you some resources to run, this class is an essential part of WordPress codebase.
Now that you know what WP_Query is and how it may benefit your WordPress site, it’s time to give it a try. Happy tinkering.
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