Tax queries and meta queries in Wordpress - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What posts are returned by this tax query?

Consider this WordPress query snippet. Which posts will it return based on the tax query?

Wordpress

<?php
$args = [
  'post_type' => 'product',
  'tax_query' => [
    [
      'taxonomy' => 'product_cat',
      'field' => 'slug',
      'terms' => ['electronics', 'appliances'],
      'operator' => 'AND'
    ]
  ]
];
$query = new WP_Query($args);
?>

A Posts in 'electronics' category only

B Posts in either 'electronics' OR 'appliances' categories

C Posts in 'appliances' category only

D Posts in both 'electronics' AND 'appliances' categories

💡 Hint

The 'operator' key controls how terms are combined in tax queries.

The 'operator' => 'AND' means posts must have all listed terms. So only posts assigned to both 'electronics' and 'appliances' categories are returned.

📝 Syntax

intermediate

Identify the syntax error in this meta query

Which option correctly fixes the syntax error in this meta query array?

Wordpress

<?php
$args = [
  'post_type' => 'post',
  'meta_query' => [
    'relation' => 'OR',
    [
      'key' => 'price',
      'value' => 100,
      'compare' => '>'
    ],
    [
      'key' => 'stock',
      'value' => 0,
      'compare' => '>='
    ]
  ]
];
$query = new WP_Query($args);
?>

A Add a comma after 'relation' => 'OR' to separate it from the first array

B Change 'compare' => '>' to 'compare' => '>' (no change needed, code is correct)

C Wrap the meta_query arrays inside another array to fix nesting

D Replace 'relation' => 'OR' with 'relation' => 'AND'

💡 Hint

Check array syntax carefully, especially commas between elements.

The 'relation' key must be separated by a comma from the next array element. Missing comma causes syntax error.

❓ state_output

advanced

What is the value of $count after this meta query?

Given this code, what is the value of $count after running the query?

Wordpress

<?php
$args = [
  'post_type' => 'event',
  'meta_query' => [
    [
      'key' => 'event_date',
      'value' => date('Y-m-d'),
      'compare' => '>=',
      'type' => 'DATE'
    ]
  ]
];
$query = new WP_Query($args);
$count = $query->found_posts;
?>

A Zero, because 'found_posts' is not set for meta queries

B Number of 'event' posts with 'event_date' today or in the future

C Number of 'event' posts with 'event_date' in the past

D Number of all 'event' posts regardless of date

💡 Hint

The meta query filters posts by date compared to today.

The meta query filters events where 'event_date' is today or later. 'found_posts' gives count of matching posts.

🔧 Debug

advanced

Why does this tax query return no posts?

This tax query returns no posts even though posts exist in the 'news' category. What is the cause?

Wordpress

<?php
$args = [
  'post_type' => 'post',
  'tax_query' => [
    [
      'taxonomy' => 'category',
      'field' => 'name',
      'terms' => 'news'
    ]
  ]
];
$query = new WP_Query($args);
?>

A 'taxonomy' should be 'post_category' instead of 'category'

B 'field' should be 'slug' instead of 'name'

C 'terms' should be an array, not a string

D Missing 'operator' key causes no results

💡 Hint

Check the data type of 'terms' in tax queries.

The 'terms' parameter must be an array even if only one term is used. Passing a string causes no matches.

🧠 Conceptual

expert

How does combining tax_query and meta_query affect results?

If a WP_Query uses both 'tax_query' and 'meta_query' arrays, how are the results filtered?

A Posts must match BOTH tax_query AND meta_query conditions

B Posts matching EITHER tax_query OR meta_query conditions are returned

C Only tax_query is applied; meta_query is ignored

D Only meta_query is applied; tax_query is ignored

💡 Hint

Think about how multiple query parameters combine in WP_Query.

WP_Query combines tax_query and meta_query with AND logic, so posts must satisfy both to be included.