Query parameters in Wordpress

Introduction

Query parameters let you filter or change what content WordPress shows by adding extra information to the URL.

You want to show posts from a specific category on a page.

You want to display search results based on user input.

You want to list posts by a certain author.

You want to paginate posts to show a limited number per page.

You want to filter posts by custom fields or tags.

Syntax

Wordpress

query_posts( array( 'key' => 'value', 'key2' => 'value2' ) );

Use an associative array to set query parameters.

Common keys include 'category_name', 'author', 'posts_per_page', 'paged', and 's' for search.

Examples

This shows posts only from the 'news' category.

Wordpress

query_posts( array( 'category_name' => 'news' ) );

This shows posts written by the author with ID 3.

Wordpress

query_posts( array( 'author' => 3 ) );

This shows 5 posts per page and displays the second page of results.

Wordpress

query_posts( array( 'posts_per_page' => 5, 'paged' => 2 ) );

This shows posts that match the search term 'apple'.

Wordpress

query_posts( array( 's' => 'apple' ) );

Sample Program

This WordPress template shows the 3 latest posts from the 'news' category. It uses query_posts with query parameters to filter posts. It loops through the posts and displays their titles and excerpts.

Wordpress

<?php
/* Template Name: Custom Query Example */
get_header();

// Show 3 latest posts from category 'news'
query_posts(array('category_name' => 'news', 'posts_per_page' => 3));

if (have_posts()) :
  while (have_posts()) : the_post();
    ?>
    <h2><?php the_title(); ?></h2>
    <p><?php the_excerpt(); ?></p>
    <?php
  endwhile;
else :
  echo '<p>No posts found.</p>';
endif;

wp_reset_query();
get_footer();
?>

Important Notes

Always use wp_reset_query() after query_posts() to avoid conflicts.

For better performance and flexibility, consider using WP_Query instead of query_posts.

Query parameters can be combined to create complex filters.

Summary

Query parameters filter WordPress content by adding conditions to the query.

They are passed as an array to query_posts or WP_Query.

Use them to show posts by category, author, search term, or pagination.