Title: WP_Tax_Query
Published: April 25, 2014
Last modified: April 28, 2025

---

# class WP_Tax_Query {}

## In this article

 * [Description](https://developer.wordpress.org/reference/classes/wp_tax_query/?output_format=md#description)
 * [Methods](https://developer.wordpress.org/reference/classes/wp_tax_query/?output_format=md#methods)
 * [Source](https://developer.wordpress.org/reference/classes/wp_tax_query/?output_format=md#source)
 * [Changelog](https://developer.wordpress.org/reference/classes/wp_tax_query/?output_format=md#changelog)
 * [User Contributed Notes](https://developer.wordpress.org/reference/classes/wp_tax_query/?output_format=md#user-contributed-notes)

[ Back to top](https://developer.wordpress.org/reference/classes/wp_tax_query/?output_format=md#wp--skip-link--target)

Core class used to implement taxonomy queries for the Taxonomy API.

## 󠀁[Description](https://developer.wordpress.org/reference/classes/wp_tax_query/?output_format=md#description)󠁿

Used for generating SQL clauses that filter a primary query according to object 
taxonomy terms.

[WP_Tax_Query](https://developer.wordpress.org/reference/classes/wp_tax_query/) 
is a helper that allows primary query classes, such as [WP_Query](https://developer.wordpress.org/reference/classes/wp_query/),
to filter their results by object metadata, by generating `JOIN` and `WHERE` subclauses
to be attached to the primary SQL query string.

## 󠀁[Methods](https://developer.wordpress.org/reference/classes/wp_tax_query/?output_format=md#methods)󠁿

| Name | Description | 
| [WP_Tax_Query::__construct](https://developer.wordpress.org/reference/classes/wp_tax_query/__construct/) | Constructor. | 
| [WP_Tax_Query::clean_query](https://developer.wordpress.org/reference/classes/wp_tax_query/clean_query/) | Validates a single query. | 
| [WP_Tax_Query::find_compatible_table_alias](https://developer.wordpress.org/reference/classes/wp_tax_query/find_compatible_table_alias/) | Identifies an existing table alias that is compatible with the current query clause. | 
| [WP_Tax_Query::get_sql](https://developer.wordpress.org/reference/classes/wp_tax_query/get_sql/) | Generates SQL clauses to be appended to a main query. | 
| [WP_Tax_Query::get_sql_clauses](https://developer.wordpress.org/reference/classes/wp_tax_query/get_sql_clauses/) | Generates SQL clauses to be appended to a main query. | 
| [WP_Tax_Query::get_sql_for_clause](https://developer.wordpress.org/reference/classes/wp_tax_query/get_sql_for_clause/) | Generates SQL JOIN and WHERE clauses for a “first-order” query clause. | 
| [WP_Tax_Query::get_sql_for_query](https://developer.wordpress.org/reference/classes/wp_tax_query/get_sql_for_query/) | Generates SQL clauses for a single query array. | 
| [WP_Tax_Query::is_first_order_clause](https://developer.wordpress.org/reference/classes/wp_tax_query/is_first_order_clause/) | Determines whether a clause is first-order. | 
| [WP_Tax_Query::sanitize_query](https://developer.wordpress.org/reference/classes/wp_tax_query/sanitize_query/) | Ensures the ‘tax_query’ argument passed to the class constructor is well-formed. | 
| [WP_Tax_Query::sanitize_relation](https://developer.wordpress.org/reference/classes/wp_tax_query/sanitize_relation/) | Sanitizes a ‘relation’ operator. | 
| [WP_Tax_Query::transform_query](https://developer.wordpress.org/reference/classes/wp_tax_query/transform_query/) | Transforms a single query, from one field to another. |

## 󠀁[Source](https://developer.wordpress.org/reference/classes/wp_tax_query/?output_format=md#source)󠁿

    ```php
    class WP_Tax_Query {

    	/**
    	 * Array of taxonomy queries.
    	 *
    	 * See WP_Tax_Query::__construct() for information on tax query arguments.
    	 *
    	 * @since 3.1.0
    	 * @var array
    	 */
    	public $queries = array();

    	/**
    	 * The relation between the queries. Can be one of 'AND' or 'OR'.
    	 *
    	 * @since 3.1.0
    	 * @var string
    	 */
    	public $relation;

    	/**
    	 * Standard response when the query should not return any rows.
    	 *
    	 * @since 3.2.0
    	 * @var array<string, array<string>>
    	 */
    	private static $no_results = array(
    		'join'  => array( '' ),
    		'where' => array( '0 = 1' ),
    	);

    	/**
    	 * A flat list of table aliases used in the JOIN clauses.
    	 *
    	 * @since 4.1.0
    	 * @var array
    	 */
    	protected $table_aliases = array();

    	/**
    	 * Terms and taxonomies fetched by this query.
    	 *
    	 * We store this data in a flat array because they are referenced in a
    	 * number of places by WP_Query.
    	 *
    	 * @since 4.1.0
    	 * @var array
    	 */
    	public $queried_terms = array();

    	/**
    	 * Database table that where the metadata's objects are stored (eg $wpdb->users).
    	 *
    	 * @since 4.1.0
    	 * @var string
    	 */
    	public $primary_table;

    	/**
    	 * Column in 'primary_table' that represents the ID of the object.
    	 *
    	 * @since 4.1.0
    	 * @var string
    	 */
    	public $primary_id_column;

    	/**
    	 * Constructor.
    	 *
    	 * @since 3.1.0
    	 * @since 4.1.0 Added support for `$operator` 'NOT EXISTS' and 'EXISTS' values.
    	 *
    	 * @param array $tax_query {
    	 *     Array of taxonomy query clauses.
    	 *
    	 *     @type string $relation Optional. The MySQL keyword used to join
    	 *                            the clauses of the query. Accepts 'AND', or 'OR'. Default 'AND'.
    	 *     @type array  ...$0 {
    	 *         An array of first-order clause parameters, or another fully-formed tax query.
    	 *
    	 *         @type string           $taxonomy         Taxonomy being queried. Optional when field=term_taxonomy_id.
    	 *         @type string|int|array $terms            Term or terms to filter by.
    	 *         @type string           $field            Field to match $terms against. Accepts 'term_id', 'slug',
    	 *                                                 'name', or 'term_taxonomy_id'. Default: 'term_id'.
    	 *         @type string           $operator         MySQL operator to be used with $terms in the WHERE clause.
    	 *                                                  Accepts 'AND', 'IN', 'NOT IN', 'EXISTS', 'NOT EXISTS'.
    	 *                                                  Default: 'IN'.
    	 *         @type bool             $include_children Optional. Whether to include child terms.
    	 *                                                  Requires a $taxonomy. Default: true.
    	 *     }
    	 * }
    	 */
    	public function __construct( $tax_query ) {
    		if ( isset( $tax_query['relation'] ) ) {
    			$this->relation = $this->sanitize_relation( $tax_query['relation'] );
    		} else {
    			$this->relation = 'AND';
    		}

    		$this->queries = $this->sanitize_query( $tax_query );
    	}

    	/**
    	 * Ensures the 'tax_query' argument passed to the class constructor is well-formed.
    	 *
    	 * Ensures that each query-level clause has a 'relation' key, and that
    	 * each first-order clause contains all the necessary keys from `$defaults`.
    	 *
    	 * @since 4.1.0
    	 *
    	 * @param array $queries Array of queries clauses.
    	 * @return array Sanitized array of query clauses.
    	 */
    	public function sanitize_query( $queries ) {
    		$cleaned_query = array();

    		$defaults = array(
    			'taxonomy'         => '',
    			'terms'            => array(),
    			'field'            => 'term_id',
    			'operator'         => 'IN',
    			'include_children' => true,
    		);

    		foreach ( $queries as $key => $query ) {
    			if ( 'relation' === $key ) {
    				$cleaned_query['relation'] = $this->sanitize_relation( $query );

    				// First-order clause.
    			} elseif ( self::is_first_order_clause( $query ) ) {

    				$cleaned_clause          = array_merge( $defaults, $query );
    				$cleaned_clause['terms'] = (array) $cleaned_clause['terms'];
    				$cleaned_query[]         = $cleaned_clause;

    				/*
    				 * Keep a copy of the clause in the flate
    				 * $queried_terms array, for use in WP_Query.
    				 */
    				if ( ! empty( $cleaned_clause['taxonomy'] ) && 'NOT IN' !== $cleaned_clause['operator'] ) {
    					$taxonomy = $cleaned_clause['taxonomy'];
    					if ( ! isset( $this->queried_terms[ $taxonomy ] ) ) {
    						$this->queried_terms[ $taxonomy ] = array();
    					}

    					/*
    					 * Backward compatibility: Only store the first
    					 * 'terms' and 'field' found for a given taxonomy.
    					 */
    					if ( ! empty( $cleaned_clause['terms'] ) && ! isset( $this->queried_terms[ $taxonomy ]['terms'] ) ) {
    						$this->queried_terms[ $taxonomy ]['terms'] = $cleaned_clause['terms'];
    					}

    					if ( ! empty( $cleaned_clause['field'] ) && ! isset( $this->queried_terms[ $taxonomy ]['field'] ) ) {
    						$this->queried_terms[ $taxonomy ]['field'] = $cleaned_clause['field'];
    					}
    				}

    				// Otherwise, it's a nested query, so we recurse.
    			} elseif ( is_array( $query ) ) {
    				$cleaned_subquery = $this->sanitize_query( $query );

    				if ( ! empty( $cleaned_subquery ) ) {
    					// All queries with children must have a relation.
    					if ( ! isset( $cleaned_subquery['relation'] ) ) {
    						$cleaned_subquery['relation'] = 'AND';
    					}

    					$cleaned_query[] = $cleaned_subquery;
    				}
    			}
    		}

    		return $cleaned_query;
    	}

    	/**
    	 * Sanitizes a 'relation' operator.
    	 *
    	 * @since 4.1.0
    	 *
    	 * @param string $relation Raw relation key from the query argument.
    	 * @return string Sanitized relation. Either 'AND' or 'OR'.
    	 */
    	public function sanitize_relation( $relation ) {
    		if ( 'OR' === strtoupper( $relation ) ) {
    			return 'OR';
    		} else {
    			return 'AND';
    		}
    	}

    	/**
    	 * Determines whether a clause is first-order.
    	 *
    	 * A "first-order" clause is one that contains any of the first-order
    	 * clause keys ('terms', 'taxonomy', 'include_children', 'field',
    	 * 'operator'). An empty clause also counts as a first-order clause,
    	 * for backward compatibility. Any clause that doesn't meet this is
    	 * determined, by process of elimination, to be a higher-order query.
    	 *
    	 * @since 4.1.0
    	 *
    	 * @param array $query Tax query arguments.
    	 * @return bool Whether the query clause is a first-order clause.
    	 */
    	protected static function is_first_order_clause( $query ) {
    		return is_array( $query ) && ( empty( $query ) || array_key_exists( 'terms', $query ) || array_key_exists( 'taxonomy', $query ) || array_key_exists( 'include_children', $query ) || array_key_exists( 'field', $query ) || array_key_exists( 'operator', $query ) );
    	}

    	/**
    	 * Generates SQL clauses to be appended to a main query.
    	 *
    	 * @since 3.1.0
    	 *
    	 * @param string $primary_table     Database table where the object being filtered is stored (eg wp_users).
    	 * @param string $primary_id_column ID column for the filtered object in $primary_table.
    	 * @return string[] {
    	 *     Array containing JOIN and WHERE SQL clauses to append to the main query.
    	 *
    	 *     @type string $join  SQL fragment to append to the main JOIN clause.
    	 *     @type string $where SQL fragment to append to the main WHERE clause.
    	 * }
    	 */
    	public function get_sql( $primary_table, $primary_id_column ) {
    		$this->primary_table     = $primary_table;
    		$this->primary_id_column = $primary_id_column;

    		return $this->get_sql_clauses();
    	}

    	/**
    	 * Generates SQL clauses to be appended to a main query.
    	 *
    	 * Called by the public WP_Tax_Query::get_sql(), this method
    	 * is abstracted out to maintain parity with the other Query classes.
    	 *
    	 * @since 4.1.0
    	 *
    	 * @return string[] {
    	 *     Array containing JOIN and WHERE SQL clauses to append to the main query.
    	 *
    	 *     @type string $join  SQL fragment to append to the main JOIN clause.
    	 *     @type string $where SQL fragment to append to the main WHERE clause.
    	 * }
    	 */
    	protected function get_sql_clauses() {
    		/*
    		 * $queries are passed by reference to get_sql_for_query() for recursion.
    		 * To keep $this->queries unaltered, pass a copy.
    		 */
    		$queries = $this->queries;
    		$sql     = $this->get_sql_for_query( $queries );

    		if ( ! empty( $sql['where'] ) ) {
    			$sql['where'] = ' AND ' . $sql['where'];
    		}

    		return $sql;
    	}

    	/**
    	 * Generates SQL clauses for a single query array.
    	 *
    	 * If nested subqueries are found, this method recurses the tree to
    	 * produce the properly nested SQL.
    	 *
    	 * @since 4.1.0
    	 *
    	 * @param array $query Query to parse (passed by reference).
    	 * @param int   $depth Optional. Number of tree levels deep we currently are.
    	 *                     Used to calculate indentation. Default 0.
    	 * @return string[] {
    	 *     Array containing JOIN and WHERE SQL clauses to append to a single query array.
    	 *
    	 *     @type string $join  SQL fragment to append to the main JOIN clause.
    	 *     @type string $where SQL fragment to append to the main WHERE clause.
    	 * }
    	 */
    	protected function get_sql_for_query( &$query, $depth = 0 ) {
    		$sql_chunks = array(
    			'join'  => array(),
    			'where' => array(),
    		);

    		$sql = array(
    			'join'  => '',
    			'where' => '',
    		);

    		$indent = '';
    		for ( $i = 0; $i < $depth; $i++ ) {
    			$indent .= '  ';
    		}

    		foreach ( $query as $key => &$clause ) {
    			if ( 'relation' === $key ) {
    				$relation = $query['relation'];
    			} elseif ( is_array( $clause ) ) {

    				// This is a first-order clause.
    				if ( $this->is_first_order_clause( $clause ) ) {
    					$clause_sql = $this->get_sql_for_clause( $clause, $query );

    					$where_count = count( $clause_sql['where'] );
    					if ( ! $where_count ) {
    						$sql_chunks['where'][] = '';
    					} elseif ( 1 === $where_count ) {
    						$sql_chunks['where'][] = $clause_sql['where'][0];
    					} else {
    						$sql_chunks['where'][] = '( ' . implode( ' AND ', $clause_sql['where'] ) . ' )';
    					}

    					$sql_chunks['join'] = array_merge( $sql_chunks['join'], $clause_sql['join'] );
    					// This is a subquery, so we recurse.
    				} else {
    					$clause_sql = $this->get_sql_for_query( $clause, $depth + 1 );

    					$sql_chunks['where'][] = $clause_sql['where'];
    					$sql_chunks['join'][]  = $clause_sql['join'];
    				}
    			}
    		}

    		// Filter to remove empties.
    		$sql_chunks['join']  = array_filter( $sql_chunks['join'] );
    		$sql_chunks['where'] = array_filter( $sql_chunks['where'] );

    		if ( empty( $relation ) ) {
    			$relation = 'AND';
    		}

    		// Filter duplicate JOIN clauses and combine into a single string.
    		if ( ! empty( $sql_chunks['join'] ) ) {
    			$sql['join'] = implode( ' ', array_unique( $sql_chunks['join'] ) );
    		}

    		// Generate a single WHERE clause with proper brackets and indentation.
    		if ( ! empty( $sql_chunks['where'] ) ) {
    			$sql['where'] = '( ' . "\n  " . $indent . implode( ' ' . "\n  " . $indent . $relation . ' ' . "\n  " . $indent, $sql_chunks['where'] ) . "\n" . $indent . ')';
    		}

    		return $sql;
    	}

    	/**
    	 * Generates SQL JOIN and WHERE clauses for a "first-order" query clause.
    	 *
    	 * @since 4.1.0
    	 *
    	 * @global wpdb $wpdb The WordPress database abstraction object.
    	 *
    	 * @param array $clause       Query clause (passed by reference).
    	 * @param array $parent_query Parent query array.
    	 * @return array {
    	 *     Array containing JOIN and WHERE SQL clauses to append to a first-order query.
    	 *
    	 *     @type string[] $join  Array of SQL fragments to append to the main JOIN clause.
    	 *     @type string[] $where Array of SQL fragments to append to the main WHERE clause.
    	 * }
    	 */
    	public function get_sql_for_clause( &$clause, $parent_query ) {
    		global $wpdb;

    		$sql = array(
    			'where' => array(),
    			'join'  => array(),
    		);

    		$join  = '';
    		$where = '';

    		$this->clean_query( $clause );

    		if ( is_wp_error( $clause ) ) {
    			return self::$no_results;
    		}

    		$terms    = $clause['terms'];
    		$operator = strtoupper( $clause['operator'] );

    		if ( 'IN' === $operator ) {

    			if ( empty( $terms ) ) {
    				return self::$no_results;
    			}

    			$terms = implode( ',', $terms );

    			/*
    			 * Before creating another table join, see if this clause has a
    			 * sibling with an existing join that can be shared.
    			 */
    			$alias = $this->find_compatible_table_alias( $clause, $parent_query );
    			if ( false === $alias ) {
    				$i     = count( $this->table_aliases );
    				$alias = $i ? 'tt' . $i : $wpdb->term_relationships;

    				// Store the alias as part of a flat array to build future iterators.
    				$this->table_aliases[] = $alias;

    				// Store the alias with this clause, so later siblings can use it.
    				$clause['alias'] = $alias;

    				$join .= " LEFT JOIN $wpdb->term_relationships";
    				$join .= $i ? " AS $alias" : '';
    				$join .= " ON ($this->primary_table.$this->primary_id_column = $alias.object_id)";
    			}

    			$where = "$alias.term_taxonomy_id $operator ($terms)";

    		} elseif ( 'NOT IN' === $operator ) {

    			if ( empty( $terms ) ) {
    				return $sql;
    			}

    			$terms = implode( ',', $terms );

    			$where = "$this->primary_table.$this->primary_id_column NOT IN (
    				SELECT object_id
    				FROM $wpdb->term_relationships
    				WHERE term_taxonomy_id IN ($terms)
    			)";

    		} elseif ( 'AND' === $operator ) {

    			if ( empty( $terms ) ) {
    				return $sql;
    			}

    			$num_terms = count( $terms );

    			$terms = implode( ',', $terms );

    			$where = "(
    				SELECT COUNT(1)
    				FROM $wpdb->term_relationships
    				WHERE term_taxonomy_id IN ($terms)
    				AND object_id = $this->primary_table.$this->primary_id_column
    			) = $num_terms";

    		} elseif ( 'NOT EXISTS' === $operator || 'EXISTS' === $operator ) {

    			$where = $wpdb->prepare(
    				"$operator (
    					SELECT 1
    					FROM $wpdb->term_relationships
    					INNER JOIN $wpdb->term_taxonomy
    					ON $wpdb->term_taxonomy.term_taxonomy_id = $wpdb->term_relationships.term_taxonomy_id
    					WHERE $wpdb->term_taxonomy.taxonomy = %s
    					AND $wpdb->term_relationships.object_id = $this->primary_table.$this->primary_id_column
    				)",
    				$clause['taxonomy']
    			);

    		}

    		$sql['join'][]  = $join;
    		$sql['where'][] = $where;
    		return $sql;
    	}

    	/**
    	 * Identifies an existing table alias that is compatible with the current query clause.
    	 *
    	 * We avoid unnecessary table joins by allowing each clause to look for
    	 * an existing table alias that is compatible with the query that it
    	 * needs to perform.
    	 *
    	 * An existing alias is compatible if (a) it is a sibling of `$clause`
    	 * (ie, it's under the scope of the same relation), and (b) the combination
    	 * of operator and relation between the clauses allows for a shared table
    	 * join. In the case of WP_Tax_Query, this only applies to 'IN'
    	 * clauses that are connected by the relation 'OR'.
    	 *
    	 * @since 4.1.0
    	 *
    	 * @param array $clause       Query clause.
    	 * @param array $parent_query Parent query of $clause.
    	 * @return string|false Table alias if found, otherwise false.
    	 */
    	protected function find_compatible_table_alias( $clause, $parent_query ) {
    		$alias = false;

    		// Confidence check. Only IN queries use the JOIN syntax.
    		if ( ! isset( $clause['operator'] ) || 'IN' !== $clause['operator'] ) {
    			return $alias;
    		}

    		// Since we're only checking IN queries, we're only concerned with OR relations.
    		if ( ! isset( $parent_query['relation'] ) || 'OR' !== $parent_query['relation'] ) {
    			return $alias;
    		}

    		$compatible_operators = array( 'IN' );

    		foreach ( $parent_query as $sibling ) {
    			if ( ! is_array( $sibling ) || ! $this->is_first_order_clause( $sibling ) ) {
    				continue;
    			}

    			if ( empty( $sibling['alias'] ) || empty( $sibling['operator'] ) ) {
    				continue;
    			}

    			// The sibling must both have compatible operator to share its alias.
    			if ( in_array( strtoupper( $sibling['operator'] ), $compatible_operators, true ) ) {
    				$alias = preg_replace( '/\W/', '_', $sibling['alias'] );
    				break;
    			}
    		}

    		return $alias;
    	}

    	/**
    	 * Validates a single query.
    	 *
    	 * @since 3.2.0
    	 *
    	 * @param array $query The single query. Passed by reference.
    	 */
    	private function clean_query( &$query ) {
    		if ( empty( $query['taxonomy'] ) ) {
    			if ( 'term_taxonomy_id' !== $query['field'] ) {
    				$query = new WP_Error( 'invalid_taxonomy', __( 'Invalid taxonomy.' ) );
    				return;
    			}

    			// So long as there are shared terms, 'include_children' requires that a taxonomy is set.
    			$query['include_children'] = false;
    		} elseif ( ! taxonomy_exists( $query['taxonomy'] ) ) {
    			$query = new WP_Error( 'invalid_taxonomy', __( 'Invalid taxonomy.' ) );
    			return;
    		}

    		if ( 'slug' === $query['field'] || 'name' === $query['field'] ) {
    			$query['terms'] = array_unique( (array) $query['terms'] );
    		} else {
    			$query['terms'] = wp_parse_id_list( $query['terms'] );
    		}

    		if ( is_taxonomy_hierarchical( $query['taxonomy'] ) && $query['include_children'] ) {
    			$this->transform_query( $query, 'term_id' );

    			if ( is_wp_error( $query ) ) {
    				return;
    			}

    			$children = array();
    			foreach ( $query['terms'] as $term ) {
    				$children   = array_merge( $children, get_term_children( $term, $query['taxonomy'] ) );
    				$children[] = $term;
    			}
    			$query['terms'] = $children;
    		}

    		$this->transform_query( $query, 'term_taxonomy_id' );
    	}

    	/**
    	 * Transforms a single query, from one field to another.
    	 *
    	 * Operates on the `$query` object by reference. In the case of error,
    	 * `$query` is converted to a WP_Error object.
    	 *
    	 * @since 3.2.0
    	 *
    	 * @param array  $query           The single query. Passed by reference.
    	 * @param string $resulting_field The resulting field. Accepts 'slug', 'name', 'term_taxonomy_id',
    	 *                                or 'term_id'. Default 'term_id'.
    	 */
    	public function transform_query( &$query, $resulting_field ) {
    		if ( empty( $query['terms'] ) ) {
    			return;
    		}

    		if ( $query['field'] === $resulting_field ) {
    			return;
    		}

    		$resulting_field = sanitize_key( $resulting_field );

    		// Empty 'terms' always results in a null transformation.
    		$terms = array_filter( $query['terms'] );
    		if ( empty( $terms ) ) {
    			$query['terms'] = array();
    			$query['field'] = $resulting_field;
    			return;
    		}

    		$args = array(
    			'get'                    => 'all',
    			'number'                 => 0,
    			'taxonomy'               => $query['taxonomy'],
    			'update_term_meta_cache' => false,
    			'orderby'                => 'none',
    		);

    		// Term query parameter name depends on the 'field' being searched on.
    		switch ( $query['field'] ) {
    			case 'slug':
    				$args['slug'] = $terms;
    				break;
    			case 'name':
    				$args['name'] = $terms;
    				break;
    			case 'term_taxonomy_id':
    				$args['term_taxonomy_id'] = $terms;
    				break;
    			default:
    				$args['include'] = wp_parse_id_list( $terms );
    				break;
    		}

    		if ( ! is_taxonomy_hierarchical( $query['taxonomy'] ) ) {
    			$args['number'] = count( $terms );
    		}

    		$term_query = new WP_Term_Query();
    		$term_list  = $term_query->query( $args );

    		if ( is_wp_error( $term_list ) ) {
    			$query = $term_list;
    			return;
    		}

    		if ( 'AND' === $query['operator'] && count( $term_list ) < count( $query['terms'] ) ) {
    			$query = new WP_Error( 'inexistent_terms', __( 'Inexistent terms.' ) );
    			return;
    		}

    		$query['terms'] = wp_list_pluck( $term_list, $resulting_field );
    		$query['field'] = $resulting_field;
    	}
    }
    ```

[View all references](https://developer.wordpress.org/reference/files/wp-includes/class-wp-tax-query.php/)
[View on Trac](https://core.trac.wordpress.org/browser/tags/6.9.4/src/wp-includes/class-wp-tax-query.php#L23)
[View on GitHub](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/class-wp-tax-query.php#L23-L659)

## 󠀁[Changelog](https://developer.wordpress.org/reference/classes/wp_tax_query/?output_format=md#changelog)󠁿

| Version | Description | 
| [3.1.0](https://developer.wordpress.org/reference/since/3.1.0/) | Introduced. |

## 󠀁[User Contributed Notes](https://developer.wordpress.org/reference/classes/wp_tax_query/?output_format=md#user-contributed-notes)󠁿

 1.   [Skip to note 3 content](https://developer.wordpress.org/reference/classes/wp_tax_query/?output_format=md#comment-content-3493)
 2.    [Aurovrata Venet](https://profiles.wordpress.org/aurovrata/)  [  6 years ago  ](https://developer.wordpress.org/reference/classes/wp_tax_query/#comment-3493)
 3.  [You must log in to vote on the helpfulness of this note](https://login.wordpress.org?redirect_to=https%3A%2F%2Fdeveloper.wordpress.org%2Freference%2Fclasses%2Fwp_tax_query%2F%23comment-3493)
     Vote results for this note: 2[You must log in to vote on the helpfulness of this note](https://login.wordpress.org?redirect_to=https%3A%2F%2Fdeveloper.wordpress.org%2Freference%2Fclasses%2Fwp_tax_query%2F%23comment-3493)
 4.      ```php
         $args = array(
             'post_type' => 'album',
             'post_status' => 'publish',
             'tax_query' => array(
                 array(
                     'taxonomy' => 'genre',
                     'field'    => 'slug',
                     'terms'    => array( 'jazz', 'improv' )
                 )
             )
         );
         $query = new WP_Query( $args );
         ```
     
 5.   [Log in to add feedback](https://login.wordpress.org/?redirect_to=https%3A%2F%2Fdeveloper.wordpress.org%2Freference%2Fclasses%2Fwp_tax_query%2F%3Freplytocom%3D3493%23feedback-editor-3493)
 6.   [Skip to note 4 content](https://developer.wordpress.org/reference/classes/wp_tax_query/?output_format=md#comment-content-4178)
 7.    [nimmolo](https://profiles.wordpress.org/nimmolo/)  [  6 years ago  ](https://developer.wordpress.org/reference/classes/wp_tax_query/#comment-4178)
 8.  [You must log in to vote on the helpfulness of this note](https://login.wordpress.org?redirect_to=https%3A%2F%2Fdeveloper.wordpress.org%2Freference%2Fclasses%2Fwp_tax_query%2F%23comment-4178)
     Vote results for this note: 0[You must log in to vote on the helpfulness of this note](https://login.wordpress.org?redirect_to=https%3A%2F%2Fdeveloper.wordpress.org%2Freference%2Fclasses%2Fwp_tax_query%2F%23comment-4178)
 9.  Note that you cannot use an array for `taxonomy`:
 10.     ```php
         $args = array(
             'post_type' => 'album',
             'post_status' => 'publish',
             'tax_query' => array(
                 array(
                     'taxonomy' => array( 'genre', 'dance' ), // <-- NO! Does not work.
                     'field'    => 'slug',
                     'terms'    => array( 'jazz', 'improv', 'tango', 'jitterbug' )
                 )
             )
         );
         $query = new WP_Query( $args );
         ```
     
 11. but you can use a `relation`:
 12.     ```php
         $args = array(
             'post_type' => 'album',
             'post_status' => 'publish',
             'tax_query' => array(
         		'relation' => 'OR',
                 array(
                     'taxonomy' => 'genre',
                     'field'    => 'slug',
                     'terms'    => array( 'jazz', 'improv' )
                 ),
                 array(
                     'taxonomy' => 'dance',
                     'field'    => 'slug',
                     'terms'    => array( 'jazz', 'improv', 'tango', 'jitterbug' )
                 )
             )
         );
         $query = new WP_Query( $args );
         ```
     
 13.  [Log in to add feedback](https://login.wordpress.org/?redirect_to=https%3A%2F%2Fdeveloper.wordpress.org%2Freference%2Fclasses%2Fwp_tax_query%2F%3Freplytocom%3D4178%23feedback-editor-4178)

You must [log in](https://login.wordpress.org/?redirect_to=https%3A%2F%2Fdeveloper.wordpress.org%2Freference%2Fclasses%2Fwp_tax_query%2F)
before being able to contribute a note or feedback.