/wp-includes/class-wp-term-query.php

<?php 
 
/** 
 * Taxonomy API: WP_Term_Query class. 
 * 
 * @package WordPress 
 * @subpackage Taxonomy 
 * @since 4.6.0 
 */ 
 
/** 
 * Class used for querying terms. 
 * 
 * @since 4.6.0 
 * 
 * @see WP_Term_Query::__construct() for accepted arguments. 
 */ 
class WP_Term_Query { 
 
  /** 
   * SQL string used to perform database query. 
   * 
   * @since 4.6.0 
   * @access public 
   * @var string 
   */ 
  public $request; 
 
  /** 
   * Metadata query container. 
   * 
   * @since 4.6.0 
   * @access public 
   * @var object WP_Meta_Query 
   */ 
  public $meta_query = false; 
 
  /** 
   * Metadata query clauses. 
   * 
   * @since 4.6.0 
   * @access protected 
   * @var array 
   */ 
  protected $meta_query_clauses; 
 
  /** 
   * SQL query clauses. 
   * 
   * @since 4.6.0 
   * @access protected 
   * @var array 
   */ 
  protected $sql_clauses = array( 
      'select' => '',  
      'from' => '',  
      'where' => array(),  
      'orderby' => '',  
      'limits' => '',  
 ); 
 
  /** 
   * Query vars set by the user. 
   * 
   * @since 4.6.0 
   * @access public 
   * @var array 
   */ 
  public $query_vars; 
 
  /** 
   * Default values for query vars. 
   * 
   * @since 4.6.0 
   * @access public 
   * @var array 
   */ 
  public $query_var_defaults; 
 
  /** 
   * List of terms located by the query. 
   * 
   * @since 4.6.0 
   * @access public 
   * @var array 
   */ 
  public $terms; 
 
  /** 
   * Constructor. 
   * 
   * Sets up the term query, based on the query vars passed. 
   * 
   * @since 4.6.0 
   * @since 4.6.0 Introduced 'term_taxonomy_id' parameter. 
   * @since 4.7.0 Introduced 'object_ids' parameter. 
   * @access public 
   * 
   * @param string|array $query { 
   *     Optional. Array or query string of term query parameters. Default empty. 
   * 
   *     @type string|array $taxonomy               Taxonomy name, or array of taxonomies, to which results should 
   *                                                be limited. 
   *     @type int|array    $object_ids             Optional. Object ID, or array of object IDs. Results will be 
   *                                                limited to terms associated with these objects. 
   *     @type string       $orderby                Field(s) to order terms by. Accepts term fields ('name',  
   *                                                'slug', 'term_group', 'term_id', 'id', 'description'),  
   *                                                'count' for term taxonomy count, 'include' to match the 
   *                                                'order' of the $include param, 'meta_value', 'meta_value_num',  
   *                                                the value of `$meta_key`, the array keys of `$meta_query`, or 
   *                                                'none' to omit the ORDER BY clause. Defaults to 'name'. 
   *     @type string       $order                  Whether to order terms in ascending or descending order. 
   *                                                Accepts 'ASC' (ascending) or 'DESC' (descending). 
   *                                                Default 'ASC'. 
   *     @type bool|int     $hide_empty             Whether to hide terms not assigned to any posts. Accepts 
   *                                                1|true or 0|false. Default 1|true. 
   *     @type array|string $include                Array or comma/space-separated string of term ids to include. 
   *                                                Default empty array. 
   *     @type array|string $exclude                Array or comma/space-separated string of term ids to exclude. 
   *                                                If $include is non-empty, $exclude is ignored. 
   *                                                Default empty array. 
   *     @type array|string $exclude_tree           Array or comma/space-separated string of term ids to exclude 
   *                                                along with all of their descendant terms. If $include is 
   *                                                non-empty, $exclude_tree is ignored. Default empty array. 
   *     @type int|string   $number                 Maximum number of terms to return. Accepts ''|0 (all) or any 
   *                                                positive number. Default ''|0 (all). 
   *     @type int          $offset                 The number by which to offset the terms query. Default empty. 
   *     @type string       $fields                 Term fields to query for. Accepts 'all' (returns an array of 
   *                                                complete term objects), 'all_with_object_id' (returns an 
   *                                                array of term objects with the 'object_id' param; only works 
   *                                                when the `$fields` parameter is 'object_ids' ), 'ids' 
   *                                                (returns an array of ids), 'tt_ids' (returns an array of 
   *                                                term taxonomy ids), 'id=>parent' (returns an associative 
   *                                                array with ids as keys, parent term IDs as values), 'names' 
   *                                                (returns an array of term names), 'count' (returns the number 
   *                                                of matching terms), 'id=>name' (returns an associative array 
   *                                                with ids as keys, term names as values), or 'id=>slug' 
   *                                                (returns an associative array with ids as keys, term slugs 
   *                                                as values). Default 'all'. 
   *     @type bool         $count                  Whether to return a term count (true) or array of term objects 
   *                                                (false). Will take precedence over `$fields` if true. 
   *                                                Default false. 
   *     @type string|array $name                   Optional. Name or array of names to return term(s) for. 
   *                                                Default empty. 
   *     @type string|array $slug                   Optional. Slug or array of slugs to return term(s) for. 
   *                                                Default empty. 
   *     @type int|array    $term_taxonomy_id       Optional. Term taxonomy ID, or array of term taxonomy IDs,  
   *                                                to match when querying terms. 
   *     @type bool         $hierarchical           Whether to include terms that have non-empty descendants (even 
   *                                                if $hide_empty is set to true). Default true. 
   *     @type string       $search                 Search criteria to match terms. Will be SQL-formatted with 
   *                                                wildcards before and after. Default empty. 
   *     @type string       $name__like             Retrieve terms with criteria by which a term is LIKE 
   *                                                `$name__like`. Default empty. 
   *     @type string       $description__like      Retrieve terms where the description is LIKE 
   *                                                `$description__like`. Default empty. 
   *     @type bool         $pad_counts             Whether to pad the quantity of a term's children in the 
   *                                                quantity of each term's "count" object variable. 
   *                                                Default false. 
   *     @type string       $get                    Whether to return terms regardless of ancestry or whether the 
   *                                                terms are empty. Accepts 'all' or empty (disabled). 
   *                                                Default empty. 
   *     @type int          $child_of               Term ID to retrieve child terms of. If multiple taxonomies 
   *                                                are passed, $child_of is ignored. Default 0. 
   *     @type int|string   $parent                 Parent term ID to retrieve direct-child terms of. 
   *                                                Default empty. 
   *     @type bool         $childless              True to limit results to terms that have no children. 
   *                                                This parameter has no effect on non-hierarchical taxonomies. 
   *                                                Default false. 
   *     @type string       $cache_domain           Unique cache key to be produced when this query is stored in 
   *                                                an object cache. Default is 'core'. 
   *     @type bool         $update_term_meta_cache Whether to prime meta caches for matched terms. Default true. 
   *     @type array        $meta_query             Optional. Meta query clauses to limit retrieved terms by. 
   *                                                See `WP_Meta_Query`. Default empty. 
   *     @type string       $meta_key               Limit terms to those matching a specific metadata key. 
   *                                                Can be used in conjunction with `$meta_value`. 
   *     @type string       $meta_value             Limit terms to those matching a specific metadata value. 
   *                                                Usually used in conjunction with `$meta_key`. 
   * } 
   */ 
  public function __construct( $query = '' ) { 
      $this->query_var_defaults = array( 
          'taxonomy' => null,  
          'object_ids' => null,  
          'orderby' => 'name',  
          'order' => 'ASC',  
          'hide_empty' => true,  
          'include' => array(),  
          'exclude' => array(),  
          'exclude_tree' => array(),  
          'number' => '',  
          'offset' => '',  
          'fields' => 'all',  
          'count' => false,  
          'name' => '',  
          'slug' => '',  
          'term_taxonomy_id' => '',  
          'hierarchical' => true,  
          'search' => '',  
          'name__like' => '',  
          'description__like' => '',  
          'pad_counts' => false,  
          'get' => '',  
          'child_of' => 0,  
          'parent' => '',  
          'childless' => false,  
          'cache_domain' => 'core',  
          'update_term_meta_cache' => true,  
          'meta_query' => '',  
          'meta_key' => '',  
          'meta_value' => '',  
          'meta_type' => '',  
          'meta_compare' => '',  
 ); 
 
      if ( ! empty( $query ) ) { 
          $this->query( $query ); 
      } 
  } 
 
  /** 
   * Parse arguments passed to the term query with default query parameters. 
   * 
   * @since 4.6.0 
   * @access public 
   * 
   * @param string|array $query WP_Term_Query arguments. See WP_Term_Query::__construct() 
   */ 
  public function parse_query( $query = '' ) { 
      if ( empty( $query ) ) { 
          $query = $this->query_vars; 
      } 
 
      $taxonomies = isset( $query['taxonomy'] ) ? (array) $query['taxonomy'] : null; 
 
      /** 
       * Filters the terms query default arguments. 
       * 
       * Use {@see 'get_terms_args'} to filter the passed arguments. 
       * 
       * @since 4.4.0 
       * 
       * @param array $defaults   An array of default get_terms() arguments. 
       * @param array $taxonomies An array of taxonomies. 
       */ 
      $this->query_var_defaults = apply_filters( 'get_terms_defaults', $this->query_var_defaults, $taxonomies ); 
 
      $query = wp_parse_args( $query, $this->query_var_defaults ); 
 
      $query['number'] = absint( $query['number'] ); 
      $query['offset'] = absint( $query['offset'] ); 
 
      // 'parent' overrides 'child_of'. 
      if ( 0 < intval( $query['parent'] ) ) { 
          $query['child_of'] = false; 
      } 
 
      if ( 'all' == $query['get'] ) { 
          $query['childless'] = false; 
          $query['child_of'] = 0; 
          $query['hide_empty'] = 0; 
          $query['hierarchical'] = false; 
          $query['pad_counts'] = false; 
      } 
 
      $query['taxonomy'] = $taxonomies; 
 
      $this->query_vars = $query; 
 
      /** 
       * Fires after term query vars have been parsed. 
       * 
       * @since 4.6.0 
       * 
       * @param WP_Term_Query $this Current instance of WP_Term_Query. 
       */ 
      do_action( 'parse_term_query', $this ); 
  } 
 
  /** 
   * Sets up the query for retrieving terms. 
   * 
   * @since 4.6.0 
   * @access public 
   * 
   * @param string|array $query Array or URL query string of parameters. 
   * @return array|int List of terms, or number of terms when 'count' is passed as a query var. 
   */ 
  public function query( $query ) { 
      $this->query_vars = wp_parse_args( $query ); 
      return $this->get_terms(); 
  } 
 
  /** 
   * Get terms, based on query_vars. 
   * 
   * @param 4.6.0 
   * @access public 
   * 
   * @global wpdb $wpdb WordPress database abstraction object. 
   * 
   * @return array 
   */ 
  public function get_terms() { 
      global $wpdb; 
 
      $this->parse_query( $this->query_vars ); 
      $args = $this->query_vars; 
 
      // Set up meta_query so it's available to 'pre_get_terms'. 
      $this->meta_query = new WP_Meta_Query(); 
      $this->meta_query->parse_query_vars( $args ); 
 
      /** 
       * Fires before terms are retrieved. 
       * 
       * @since 4.6.0 
       * 
       * @param WP_Term_Query $this Current instance of WP_Term_Query. 
       */ 
      do_action( 'pre_get_terms', $this ); 
 
      $taxonomies = $args['taxonomy']; 
 
      // Save queries by not crawling the tree in the case of multiple taxes or a flat tax. 
      $has_hierarchical_tax = false; 
      if ( $taxonomies ) { 
          foreach ( $taxonomies as $_tax ) { 
              if ( is_taxonomy_hierarchical( $_tax ) ) { 
                  $has_hierarchical_tax = true; 
              } 
          } 
      } 
 
      if ( ! $has_hierarchical_tax ) { 
          $args['hierarchical'] = false; 
          $args['pad_counts'] = false; 
      } 
 
      // 'parent' overrides 'child_of'. 
      if ( 0 < intval( $args['parent'] ) ) { 
          $args['child_of'] = false; 
      } 
 
      if ( 'all' == $args['get'] ) { 
          $args['childless'] = false; 
          $args['child_of'] = 0; 
          $args['hide_empty'] = 0; 
          $args['hierarchical'] = false; 
          $args['pad_counts'] = false; 
      } 
 
      /** 
       * Filters the terms query arguments. 
       * 
       * @since 3.1.0 
       * 
       * @param array $args       An array of get_terms() arguments. 
       * @param array $taxonomies An array of taxonomies. 
       */ 
      $args = apply_filters( 'get_terms_args', $args, $taxonomies ); 
 
      // Avoid the query if the queried parent/child_of term has no descendants. 
      $child_of = $args['child_of']; 
      $parent = $args['parent']; 
 
      if ( $child_of ) { 
          $_parent = $child_of; 
      } elseif ( $parent ) { 
          $_parent = $parent; 
      } else { 
          $_parent = false; 
      } 
 
      if ( $_parent ) { 
          $in_hierarchy = false; 
          foreach ( $taxonomies as $_tax ) { 
              $hierarchy = _get_term_hierarchy( $_tax ); 
 
              if ( isset( $hierarchy[ $_parent ] ) ) { 
                  $in_hierarchy = true; 
              } 
          } 
 
          if ( ! $in_hierarchy ) { 
              return array(); 
          } 
      } 
 
      // 'term_order' is a legal sort order only when joining the relationship table. 
      $_orderby = $this->query_vars['orderby']; 
      if ( 'term_order' === $_orderby && empty( $this->query_vars['object_ids'] ) ) { 
          $_orderby = 'term_id'; 
      } 
      $orderby = $this->parse_orderby( $_orderby ); 
 
      if ( $orderby ) { 
          $orderby = "ORDER BY $orderby"; 
      } 
 
      $order = $this->parse_order( $this->query_vars['order'] ); 
 
      if ( $taxonomies ) { 
          $this->sql_clauses['where']['taxonomy'] = "tt.taxonomy IN ('" . implode( "', '", array_map( 'esc_sql', $taxonomies ) ) . "')"; 
      } 
 
      $exclude = $args['exclude']; 
      $exclude_tree = $args['exclude_tree']; 
      $include = $args['include']; 
 
      $inclusions = ''; 
      if ( ! empty( $include ) ) { 
          $exclude = ''; 
          $exclude_tree = ''; 
          $inclusions = implode( ', ', wp_parse_id_list( $include ) ); 
      } 
 
      if ( ! empty( $inclusions ) ) { 
          $this->sql_clauses['where']['inclusions'] = 't.term_id IN ( ' . $inclusions . ' )'; 
      } 
 
      $exclusions = array(); 
      if ( ! empty( $exclude_tree ) ) { 
          $exclude_tree = wp_parse_id_list( $exclude_tree ); 
          $excluded_children = $exclude_tree; 
          foreach ( $exclude_tree as $extrunk ) { 
              $excluded_children = array_merge( 
                  $excluded_children,  
                  (array) get_terms( $taxonomies[0], array( 
                      'child_of' => intval( $extrunk ),  
                      'fields' => 'ids',  
                      'hide_empty' => 0 
 ) ) 
 ); 
          } 
          $exclusions = array_merge( $excluded_children, $exclusions ); 
      } 
 
      if ( ! empty( $exclude ) ) { 
          $exclusions = array_merge( wp_parse_id_list( $exclude ), $exclusions ); 
      } 
 
      // 'childless' terms are those without an entry in the flattened term hierarchy. 
      $childless = (bool) $args['childless']; 
      if ( $childless ) { 
          foreach ( $taxonomies as $_tax ) { 
              $term_hierarchy = _get_term_hierarchy( $_tax ); 
              $exclusions = array_merge( array_keys( $term_hierarchy ), $exclusions ); 
          } 
      } 
 
      if ( ! empty( $exclusions ) ) { 
          $exclusions = 't.term_id NOT IN (' . implode( ', ', array_map( 'intval', $exclusions ) ) . ')'; 
      } else { 
          $exclusions = ''; 
      } 
 
      /** 
       * Filters the terms to exclude from the terms query. 
       * 
       * @since 2.3.0 
       * 
       * @param string $exclusions `NOT IN` clause of the terms query. 
       * @param array  $args       An array of terms query arguments. 
       * @param array  $taxonomies An array of taxonomies. 
       */ 
      $exclusions = apply_filters( 'list_terms_exclusions', $exclusions, $args, $taxonomies ); 
 
      if ( ! empty( $exclusions ) ) { 
          // Must do string manipulation here for backward compatibility with filter. 
          $this->sql_clauses['where']['exclusions'] = preg_replace( '/^\s*AND\s*/', '', $exclusions ); 
      } 
 
      if ( ! empty( $args['name'] ) ) { 
          $names = (array) $args['name']; 
          foreach ( $names as &$_name ) { 
              // `sanitize_term_field()` returns slashed data. 
              $_name = stripslashes( sanitize_term_field( 'name', $_name, 0, reset( $taxonomies ), 'db' ) ); 
          } 
 
          $this->sql_clauses['where']['name'] = "t.name IN ('" . implode( "', '", array_map( 'esc_sql', $names ) ) . "')"; 
      } 
 
      if ( ! empty( $args['slug'] ) ) { 
          if ( is_array( $args['slug'] ) ) { 
              $slug = array_map( 'sanitize_title', $args['slug'] ); 
              $this->sql_clauses['where']['slug'] = "t.slug IN ('" . implode( "', '", $slug ) . "')"; 
          } else { 
              $slug = sanitize_title( $args['slug'] ); 
              $this->sql_clauses['where']['slug'] = "t.slug = '$slug'"; 
          } 
      } 
 
      if ( ! empty( $args['term_taxonomy_id'] ) ) { 
          if ( is_array( $args['term_taxonomy_id'] ) ) { 
              $tt_ids = implode( ', ', array_map( 'intval', $args['term_taxonomy_id'] ) ); 
              $this->sql_clauses['where']['term_taxonomy_id'] = "tt.term_taxonomy_id IN ({$tt_ids})"; 
          } else { 
              $this->sql_clauses['where']['term_taxonomy_id'] = $wpdb->prepare( "tt.term_taxonomy_id = %d", $args['term_taxonomy_id'] ); 
          } 
      } 
 
      if ( ! empty( $args['name__like'] ) ) { 
          $this->sql_clauses['where']['name__like'] = $wpdb->prepare( "t.name LIKE %s", '%' . $wpdb->esc_like( $args['name__like'] ) . '%' ); 
      } 
 
      if ( ! empty( $args['description__like'] ) ) { 
          $this->sql_clauses['where']['description__like'] = $wpdb->prepare( "tt.description LIKE %s", '%' . $wpdb->esc_like( $args['description__like'] ) . '%' ); 
      } 
 
      if ( ! empty( $args['object_ids'] ) ) { 
          $object_ids = $args['object_ids']; 
          if ( ! is_array( $object_ids ) ) { 
              $object_ids = array( $object_ids ); 
          } 
 
          $object_ids = implode( ', ', array_map( 'intval', $object_ids ) ); 
          $this->sql_clauses['where']['object_ids'] = "tr.object_id IN ($object_ids)"; 
      } 
 
      /** 
       * When querying for object relationships, the 'count > 0' check 
       * added by 'hide_empty' is superfluous. 
       */ 
      if ( ! empty( $args['object_ids'] ) ) { 
          $args['hide_empty'] = false; 
      } 
 
      if ( '' !== $parent ) { 
          $parent = (int) $parent; 
          $this->sql_clauses['where']['parent'] = "tt.parent = '$parent'"; 
      } 
 
      $hierarchical = $args['hierarchical']; 
      if ( 'count' == $args['fields'] ) { 
          $hierarchical = false; 
      } 
      if ( $args['hide_empty'] && !$hierarchical ) { 
          $this->sql_clauses['where']['count'] = 'tt.count > 0'; 
      } 
 
      $number = $args['number']; 
      $offset = $args['offset']; 
 
      // Don't limit the query results when we have to descend the family tree. 
      if ( $number && ! $hierarchical && ! $child_of && '' === $parent ) { 
          if ( $offset ) { 
              $limits = 'LIMIT ' . $offset . ', ' . $number; 
          } else { 
              $limits = 'LIMIT ' . $number; 
          } 
      } else { 
          $limits = ''; 
      } 
 
 
      if ( ! empty( $args['search'] ) ) { 
          $this->sql_clauses['where']['search'] = $this->get_search_sql( $args['search'] ); 
      } 
 
      // Meta query support. 
      $join = ''; 
      $distinct = ''; 
 
      // Reparse meta_query query_vars, in case they were modified in a 'pre_get_terms' callback. 
      $this->meta_query->parse_query_vars( $this->query_vars ); 
      $mq_sql = $this->meta_query->get_sql( 'term', 't', 'term_id' ); 
      $meta_clauses = $this->meta_query->get_clauses(); 
 
      if ( ! empty( $meta_clauses ) ) { 
          $join .= $mq_sql['join']; 
          $this->sql_clauses['where']['meta_query'] = preg_replace( '/^\s*AND\s*/', '', $mq_sql['where'] ); 
          $distinct .= "DISTINCT"; 
 
      } 
 
      $selects = array(); 
      switch ( $args['fields'] ) { 
          case 'all': 
          case 'all_with_object_id' : 
          case 'tt_ids' : 
          case 'slugs' : 
              $selects = array( 't.*', 'tt.*' ); 
              if ( 'all_with_object_id' === $args['fields'] && ! empty( $args['object_ids'] ) ) { 
                  $selects[] = 'tr.object_id'; 
              } 
              break; 
          case 'ids': 
          case 'id=>parent': 
              $selects = array( 't.term_id', 'tt.parent', 'tt.count', 'tt.taxonomy' ); 
              break; 
          case 'names': 
              $selects = array( 't.term_id', 'tt.parent', 'tt.count', 't.name', 'tt.taxonomy' ); 
              break; 
          case 'count': 
              $orderby = ''; 
              $order = ''; 
              $selects = array( 'COUNT(*)' ); 
              break; 
          case 'id=>name': 
              $selects = array( 't.term_id', 't.name', 'tt.count', 'tt.taxonomy' ); 
              break; 
          case 'id=>slug': 
              $selects = array( 't.term_id', 't.slug', 'tt.count', 'tt.taxonomy' ); 
              break; 
      } 
 
      $_fields = $args['fields']; 
 
      /** 
       * Filters the fields to select in the terms query. 
       * 
       * Field lists modified using this filter will only modify the term fields returned 
       * by the function when the `$fields` parameter set to 'count' or 'all'. In all other 
       * cases, the term fields in the results array will be determined by the `$fields` 
       * parameter alone. 
       * 
       * Use of this filter can result in unpredictable behavior, and is not recommended. 
       * 
       * @since 2.8.0 
       * 
       * @param array $selects    An array of fields to select for the terms query. 
       * @param array $args       An array of term query arguments. 
       * @param array $taxonomies An array of taxonomies. 
       */ 
      $fields = implode( ', ', apply_filters( 'get_terms_fields', $selects, $args, $taxonomies ) ); 
 
      $join .= " INNER JOIN $wpdb->term_taxonomy AS tt ON t.term_id = tt.term_id"; 
 
      if ( ! empty( $this->query_vars['object_ids'] ) ) { 
          $join .= " INNER JOIN {$wpdb->term_relationships} AS tr ON tr.term_taxonomy_id = tt.term_taxonomy_id"; 
      } 
 
      $where = implode( ' AND ', $this->sql_clauses['where'] ); 
 
      /** 
       * Filters the terms query SQL clauses. 
       * 
       * @since 3.1.0 
       * 
       * @param array $pieces     Terms query SQL clauses. 
       * @param array $taxonomies An array of taxonomies. 
       * @param array $args       An array of terms query arguments. 
       */ 
      $clauses = apply_filters( 'terms_clauses', compact( 'fields', 'join', 'where', 'distinct', 'orderby', 'order', 'limits' ), $taxonomies, $args ); 
 
      $fields = isset( $clauses[ 'fields' ] ) ? $clauses[ 'fields' ] : ''; 
      $join = isset( $clauses[ 'join' ] ) ? $clauses[ 'join' ] : ''; 
      $where = isset( $clauses[ 'where' ] ) ? $clauses[ 'where' ] : ''; 
      $distinct = isset( $clauses[ 'distinct' ] ) ? $clauses[ 'distinct' ] : ''; 
      $orderby = isset( $clauses[ 'orderby' ] ) ? $clauses[ 'orderby' ] : ''; 
      $order = isset( $clauses[ 'order' ] ) ? $clauses[ 'order' ] : ''; 
      $limits = isset( $clauses[ 'limits' ] ) ? $clauses[ 'limits' ] : ''; 
 
      if ( $where ) { 
          $where = "WHERE $where"; 
      } 
 
      $this->sql_clauses['select'] = "SELECT $distinct $fields"; 
      $this->sql_clauses['from'] = "FROM $wpdb->terms AS t $join"; 
      $this->sql_clauses['orderby'] = $orderby ? "$orderby $order" : ''; 
      $this->sql_clauses['limits'] = $limits; 
 
      $this->request = "{$this->sql_clauses['select']} {$this->sql_clauses['from']} {$where} {$this->sql_clauses['orderby']} {$this->sql_clauses['limits']}"; 
 
      // $args can be anything. Only use the args defined in defaults to compute the key. 
      $key = md5( serialize( wp_array_slice_assoc( $args, array_keys( $this->query_var_defaults ) ) ) . serialize( $taxonomies ) . $this->request ); 
      $last_changed = wp_cache_get_last_changed( 'terms' ); 
      $cache_key = "get_terms:$key:$last_changed"; 
      $cache = wp_cache_get( $cache_key, 'terms' ); 
      if ( false !== $cache ) { 
          if ( 'all' === $_fields ) { 
              $cache = array_map( 'get_term', $cache ); 
          } 
 
          $this->terms = $cache; 
          return $this->terms; 
      } 
 
      if ( 'count' == $_fields ) { 
          $count = $wpdb->get_var( $this->request ); 
          wp_cache_set( $cache_key, $count, 'terms' ); 
          return $count; 
      } 
 
      $terms = $wpdb->get_results( $this->request ); 
      if ( 'all' == $_fields || 'all_with_object_id' === $_fields ) { 
          update_term_cache( $terms ); 
      } 
 
      // Prime termmeta cache. 
      if ( $args['update_term_meta_cache'] ) { 
          $term_ids = wp_list_pluck( $terms, 'term_id' ); 
          update_termmeta_cache( $term_ids ); 
      } 
 
      if ( empty( $terms ) ) { 
          wp_cache_add( $cache_key, array(), 'terms', DAY_IN_SECONDS ); 
          return array(); 
      } 
 
      if ( $child_of ) { 
          foreach ( $taxonomies as $_tax ) { 
              $children = _get_term_hierarchy( $_tax ); 
              if ( ! empty( $children ) ) { 
                  $terms = _get_term_children( $child_of, $terms, $_tax ); 
              } 
          } 
      } 
 
      // Update term counts to include children. 
      if ( $args['pad_counts'] && 'all' == $_fields ) { 
          foreach ( $taxonomies as $_tax ) { 
              _pad_term_counts( $terms, $_tax ); 
          } 
      } 
 
      // Make sure we show empty categories that have children. 
      if ( $hierarchical && $args['hide_empty'] && is_array( $terms ) ) { 
          foreach ( $terms as $k => $term ) { 
              if ( ! $term->count ) { 
                  $children = get_term_children( $term->term_id, $term->taxonomy ); 
                  if ( is_array( $children ) ) { 
                      foreach ( $children as $child_id ) { 
                          $child = get_term( $child_id, $term->taxonomy ); 
                          if ( $child->count ) { 
                              continue 2; 
                          } 
                      } 
                  } 
 
                  // It really is empty. 
                  unset( $terms[ $k ] ); 
              } 
          } 
      } 
 
      /** 
       * When querying for terms connected to objects, we may get 
       * duplicate results. The duplicates should be preserved if 
       * `$fields` is 'all_with_object_id', but should otherwise be 
       * removed. 
       */ 
      if ( ! empty( $args['object_ids'] ) && 'all_with_object_id' != $_fields ) { 
          $_tt_ids = $_terms = array(); 
          foreach ( $terms as $term ) { 
              if ( isset( $_tt_ids[ $term->term_id ] ) ) { 
                  continue; 
              } 
 
              $_tt_ids[ $term->term_id ] = 1; 
              $_terms[] = $term; 
          } 
 
          $terms = $_terms; 
      } 
 
      $_terms = array(); 
      if ( 'id=>parent' == $_fields ) { 
          foreach ( $terms as $term ) { 
              $_terms[ $term->term_id ] = $term->parent; 
          } 
      } elseif ( 'ids' == $_fields ) { 
          foreach ( $terms as $term ) { 
              $_terms[] = (int) $term->term_id; 
          } 
      } elseif ( 'tt_ids' == $_fields ) { 
          foreach ( $terms as $term ) { 
              $_terms[] = (int) $term->term_taxonomy_id; 
          } 
      } elseif ( 'names' == $_fields ) { 
          foreach ( $terms as $term ) { 
              $_terms[] = $term->name; 
          } 
      } elseif ( 'slugs' == $_fields ) { 
          foreach ( $terms as $term ) { 
              $_terms[] = $term->slug; 
          } 
      } elseif ( 'id=>name' == $_fields ) { 
          foreach ( $terms as $term ) { 
              $_terms[ $term->term_id ] = $term->name; 
          } 
      } elseif ( 'id=>slug' == $_fields ) { 
          foreach ( $terms as $term ) { 
              $_terms[ $term->term_id ] = $term->slug; 
          } 
      } 
 
      if ( ! empty( $_terms ) ) { 
          $terms = $_terms; 
      } 
 
      // Hierarchical queries are not limited, so 'offset' and 'number' must be handled now. 
      if ( $hierarchical && $number && is_array( $terms ) ) { 
          if ( $offset >= count( $terms ) ) { 
              $terms = array(); 
          } else { 
              $terms = array_slice( $terms, $offset, $number, true ); 
          } 
      } 
 
      wp_cache_add( $cache_key, $terms, 'terms', DAY_IN_SECONDS ); 
 
      if ( 'all' === $_fields || 'all_with_object_id' === $_fields ) { 
          $terms = array_map( 'get_term', $terms ); 
      } 
 
      $this->terms = $terms; 
      return $this->terms; 
  } 
 
  /** 
   * Parse and sanitize 'orderby' keys passed to the term query. 
   * 
   * @since 4.6.0 
   * @access protected 
   * 
   * @global wpdb $wpdb WordPress database abstraction object. 
   * 
   * @param string $orderby_raw Alias for the field to order by. 
   * @return string|false Value to used in the ORDER clause. False otherwise. 
   */ 
  protected function parse_orderby( $orderby_raw ) { 
      $_orderby = strtolower( $orderby_raw ); 
      $maybe_orderby_meta = false; 
 
      if ( in_array( $_orderby, array( 'term_id', 'name', 'slug', 'term_group' ), true ) ) { 
          $orderby = "t.$_orderby"; 
      } elseif ( in_array( $_orderby, array( 'count', 'parent', 'taxonomy', 'term_taxonomy_id', 'description' ), true ) ) { 
          $orderby = "tt.$_orderby"; 
      } elseif ( 'term_order' === $_orderby ) { 
          $orderby = 'tr.term_order'; 
      } elseif ( 'include' == $_orderby && ! empty( $this->query_vars['include'] ) ) { 
          $include = implode( ', ', wp_parse_id_list( $this->query_vars['include'] ) ); 
          $orderby = "FIELD( t.term_id, $include )"; 
      } elseif ( 'none' == $_orderby ) { 
          $orderby = ''; 
      } elseif ( empty( $_orderby ) || 'id' == $_orderby || 'term_id' === $_orderby ) { 
          $orderby = 't.term_id'; 
      } else { 
          $orderby = 't.name'; 
 
          // This may be a value of orderby related to meta. 
          $maybe_orderby_meta = true; 
      } 
 
      /** 
       * Filters the ORDERBY clause of the terms query. 
       * 
       * @since 2.8.0 
       * 
       * @param string $orderby    `ORDERBY` clause of the terms query. 
       * @param array  $args       An array of terms query arguments. 
       * @param array  $taxonomies An array of taxonomies. 
       */ 
      $orderby = apply_filters( 'get_terms_orderby', $orderby, $this->query_vars, $this->query_vars['taxonomy'] ); 
 
      // Run after the 'get_terms_orderby' filter for backward compatibility. 
      if ( $maybe_orderby_meta ) { 
          $maybe_orderby_meta = $this->parse_orderby_meta( $_orderby ); 
          if ( $maybe_orderby_meta ) { 
              $orderby = $maybe_orderby_meta; 
          } 
      } 
 
      return $orderby; 
  } 
 
  /** 
   * Generate the ORDER BY clause for an 'orderby' param that is potentially related to a meta query. 
   * 
   * @since 4.6.0 
   * @access public 
   * 
   * @param string $orderby_raw Raw 'orderby' value passed to WP_Term_Query. 
   * @return string 
   */ 
  protected function parse_orderby_meta( $orderby_raw ) { 
      $orderby = ''; 
 
      // Tell the meta query to generate its SQL, so we have access to table aliases. 
      $this->meta_query->get_sql( 'term', 't', 'term_id' ); 
      $meta_clauses = $this->meta_query->get_clauses(); 
      if ( ! $meta_clauses || ! $orderby_raw ) { 
          return $orderby; 
      } 
 
      $allowed_keys = array(); 
      $primary_meta_key = null; 
      $primary_meta_query = reset( $meta_clauses ); 
      if ( ! empty( $primary_meta_query['key'] ) ) { 
          $primary_meta_key = $primary_meta_query['key']; 
          $allowed_keys[] = $primary_meta_key; 
      } 
      $allowed_keys[] = 'meta_value'; 
      $allowed_keys[] = 'meta_value_num'; 
      $allowed_keys = array_merge( $allowed_keys, array_keys( $meta_clauses ) ); 
 
      if ( ! in_array( $orderby_raw, $allowed_keys, true ) ) { 
          return $orderby; 
      } 
 
      switch( $orderby_raw ) { 
          case $primary_meta_key: 
          case 'meta_value': 
              if ( ! empty( $primary_meta_query['type'] ) ) { 
                  $orderby = "CAST({$primary_meta_query['alias']}.meta_value AS {$primary_meta_query['cast']})"; 
              } else { 
                  $orderby = "{$primary_meta_query['alias']}.meta_value"; 
              } 
              break; 
 
          case 'meta_value_num': 
              $orderby = "{$primary_meta_query['alias']}.meta_value+0"; 
              break; 
 
          default: 
              if ( array_key_exists( $orderby_raw, $meta_clauses ) ) { 
                  // $orderby corresponds to a meta_query clause. 
                  $meta_clause = $meta_clauses[ $orderby_raw ]; 
                  $orderby = "CAST({$meta_clause['alias']}.meta_value AS {$meta_clause['cast']})"; 
              } 
              break; 
      } 
 
      return $orderby; 
  } 
 
  /** 
   * Parse an 'order' query variable and cast it to ASC or DESC as necessary. 
   * 
   * @since 4.6.0 
   * @access protected 
   * 
   * @param string $order The 'order' query variable. 
   * @return string The sanitized 'order' query variable. 
   */ 
  protected function parse_order( $order ) { 
      if ( ! is_string( $order ) || empty( $order ) ) { 
          return 'DESC'; 
      } 
 
      if ( 'ASC' === strtoupper( $order ) ) { 
          return 'ASC'; 
      } else { 
          return 'DESC'; 
      } 
  } 
 
  /** 
   * Used internally to generate a SQL string related to the 'search' parameter. 
   * 
   * @since 4.6.0 
   * @access protected 
   * 
   * @global wpdb $wpdb WordPress database abstraction object. 
   * 
   * @param string $string 
   * @return string 
   */ 
  protected function get_search_sql( $string ) { 
      global $wpdb; 
 
      $like = '%' . $wpdb->esc_like( $string ) . '%'; 
 
      return $wpdb->prepare( '((t.name LIKE %s) OR (t.slug LIKE %s))', $like, $like ); 
  } 
}