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

   1 <?php
   2 /**
   3  * Comment API: WP_Comment_Query class
   4  *
   5  * @package WordPress
   6  * @subpackage Comments
   7  * @since 4.4.0
   8  */
   9
  10 /**
  11  * Core class used for querying comments.
  12  *
  13  * @since 3.1.0
  14  *
  15  * @see WP_Comment_Query::__construct() for accepted arguments.
  16  */
  17 class WP_Comment_Query {
  18
  19         /**
  20          * SQL for database query.
  21          *
  22          * @since 4.0.1
  23          * @access public
  24          * @var string
  25          */
  26         public $request;
  27
  28         /**
  29          * Metadata query container
  30          *
  31          * @since 3.5.0
  32          * @access public
  33          * @var object WP_Meta_Query
  34          */
  35         public $meta_query = false;
  36
  37         /**
  38          * Metadata query clauses.
  39          *
  40          * @since 4.4.0
  41          * @access protected
  42          * @var array
  43          */
  44         protected $meta_query_clauses;
  45
  46         /**
  47          * SQL query clauses.
  48          *
  49          * @since 4.4.0
  50          * @access protected
  51          * @var array
  52          */
  53         protected $sql_clauses = array(
  54                 'select'  => '',
  55                 'from'    => '',
  56                 'where'   => array(),
  57                 'groupby' => '',
  58                 'orderby' => '',
  59                 'limits'  => '',
  60         );
  61
  62         /**
  63          * SQL WHERE clause.
  64          *
  65          * Stored after the {@see 'comments_clauses'} filter is run on the compiled WHERE sub-clauses.
  66          *
  67          * @since 4.4.2
  68          * @access protected
  69          * @var string
  70          */
  71         protected $filtered_where_clause;
  72
  73         /**
  74          * Date query container
  75          *
  76          * @since 3.7.0
  77          * @access public
  78          * @var object WP_Date_Query
  79          */
  80         public $date_query = false;
  81
  82         /**
  83          * Query vars set by the user.
  84          *
  85          * @since 3.1.0
  86          * @access public
  87          * @var array
  88          */
  89         public $query_vars;
  90
  91         /**
  92          * Default values for query vars.
  93          *
  94          * @since 4.2.0
  95          * @access public
  96          * @var array
  97          */
  98         public $query_var_defaults;
  99
 100         /**
 101          * List of comments located by the query.
 102          *
 103          * @since 4.0.0
 104          * @access public
 105          * @var array
 106          */
 107         public $comments;
 108
 109         /**
 110          * The amount of found comments for the current query.
 111          *
 112          * @since 4.4.0
 113          * @access public
 114          * @var int
 115          */
 116         public $found_comments = 0;
 117
 118         /**
 119          * The number of pages.
 120          *
 121          * @since 4.4.0
 122          * @access public
 123          * @var int
 124          */
 125         public $max_num_pages = 0;
 126
 127         /**
 128          * Make private/protected methods readable for backward compatibility.
 129          *
 130          * @since 4.0.0
 131          * @access public
 132          *
 133          * @param callable $name      Method to call.
 134          * @param array    $arguments Arguments to pass when calling.
 135          * @return mixed|false Return value of the callback, false otherwise.
 136          */
 137         public function __call( $name, $arguments ) {
 138                 if ( 'get_search_sql' === $name ) {
 139                         return call_user_func_array( array( $this, $name ), $arguments );
 140                 }
 141                 return false;
 142         }
 143
 144         /**
 145          * Constructor.
 146          *
 147          * Sets up the comment query, based on the query vars passed.
 148          *
 149          * @since 4.2.0
 150          * @since 4.4.0 `$parent__in` and `$parent__not_in` were added.
 151          * @since 4.4.0 Order by `comment__in` was added. `$update_comment_meta_cache`, `$no_found_rows`,
 152          *              `$hierarchical`, and `$update_comment_post_cache` were added.
 153          * @since 4.5.0 Introduced the `$author_url` argument.
 154          * @since 4.6.0 Introduced the `$cache_domain` argument.
 155          * @access public
 156          *
 157          * @param string|array $query {
 158          *     Optional. Array or query string of comment query parameters. Default empty.
 159          *
 160          *     @type string       $author_email              Comment author email address. Default empty.
 161          *     @type string       $author_url                Comment author URL. Default empty.
 162          *     @type array        $author__in                Array of author IDs to include comments for. Default empty.
 163          *     @type array        $author__not_in            Array of author IDs to exclude comments for. Default empty.
 164          *     @type array        $comment__in               Array of comment IDs to include. Default empty.
 165          *     @type array        $comment__not_in           Array of comment IDs to exclude. Default empty.
 166          *     @type bool         $count                     Whether to return a comment count (true) or array of
 167          *                                                   comment objects (false). Default false.
 168          *     @type array        $date_query                Date query clauses to limit comments by. See WP_Date_Query.
 169          *                                                   Default null.
 170          *     @type string       $fields                    Comment fields to return. Accepts 'ids' for comment IDs
 171          *                                                   only or empty for all fields. Default empty.
 172          *     @type int          $ID                        Currently unused.
 173          *     @type array        $include_unapproved        Array of IDs or email addresses of users whose unapproved
 174          *                                                   comments will be returned by the query regardless of
 175          *                                                   `$status`. Default empty.
 176          *     @type int          $karma                     Karma score to retrieve matching comments for.
 177          *                                                   Default empty.
 178          *     @type string       $meta_key                  Include comments with a matching comment meta key.
 179          *                                                   Default empty.
 180          *     @type string       $meta_value                Include comments with a matching comment meta value.
 181          *                                                   Requires `$meta_key` to be set. Default empty.
 182          *     @type array        $meta_query                Meta query clauses to limit retrieved comments by.
 183          *                                                   See WP_Meta_Query. Default empty.
 184          *     @type int          $number                    Maximum number of comments to retrieve.
 185          *                                                   Default null (no limit).
 186          *     @type int          $offset                    Number of comments to offset the query. Used to build
 187          *                                                   LIMIT clause. Default 0.
 188          *     @type bool         $no_found_rows             Whether to disable the `SQL_CALC_FOUND_ROWS` query.
 189          *                                                   Default: true.
 190          *     @type string|array $orderby                   Comment status or array of statuses. To use 'meta_value'
 191          *                                                   or 'meta_value_num', `$meta_key` must also be defined.
 192          *                                                   To sort by a specific `$meta_query` clause, use that
 193          *                                                   clause's array key. Accepts 'comment_agent',
 194          *                                                   'comment_approved', 'comment_author',
 195          *                                                   'comment_author_email', 'comment_author_IP',
 196          *                                                   'comment_author_url', 'comment_content', 'comment_date',
 197          *                                                   'comment_date_gmt', 'comment_ID', 'comment_karma',
 198          *                                                   'comment_parent', 'comment_post_ID', 'comment_type',
 199          *                                                   'user_id', 'comment__in', 'meta_value', 'meta_value_num',
 200          *                                                   the value of $meta_key, and the array keys of
 201          *                                                   `$meta_query`. Also accepts false, an empty array, or
 202          *                                                   'none' to disable `ORDER BY` clause.
 203          *                                                   Default: 'comment_date_gmt'.
 204          *     @type string       $order                     How to order retrieved comments. Accepts 'ASC', 'DESC'.
 205          *                                                   Default: 'DESC'.
 206          *     @type int          $parent                    Parent ID of comment to retrieve children of.
 207          *                                                   Default empty.
 208          *     @type array        $parent__in                Array of parent IDs of comments to retrieve children for.
 209          *                                                   Default empty.
 210          *     @type array        $parent__not_in            Array of parent IDs of comments *not* to retrieve
 211          *                                                   children for. Default empty.
 212          *     @type array        $post_author__in           Array of author IDs to retrieve comments for.
 213          *                                                   Default empty.
 214          *     @type array        $post_author__not_in       Array of author IDs *not* to retrieve comments for.
 215          *                                                   Default empty.
 216          *     @type int          $post_ID                   Currently unused.
 217          *     @type int          $post_id                   Limit results to those affiliated with a given post ID.
 218          *                                                   Default 0.
 219          *     @type array        $post__in                  Array of post IDs to include affiliated comments for.
 220          *                                                   Default empty.
 221          *     @type array        $post__not_in              Array of post IDs to exclude affiliated comments for.
 222          *                                                   Default empty.
 223          *     @type int          $post_author               Post author ID to limit results by. Default empty.
 224          *     @type string|array $post_status               Post status or array of post statuses to retrieve
 225          *                                                   affiliated comments for. Pass 'any' to match any value.
 226          *                                                   Default empty.
 227          *     @type string       $post_type                 Post type or array of post types to retrieve affiliated
 228          *                                                   comments for. Pass 'any' to match any value. Default empty.
 229          *     @type string       $post_name                 Post name to retrieve affiliated comments for.
 230          *                                                   Default empty.
 231          *     @type int          $post_parent               Post parent ID to retrieve affiliated comments for.
 232          *                                                   Default empty.
 233          *     @type string       $search                    Search term(s) to retrieve matching comments for.
 234          *                                                   Default empty.
 235          *     @type string       $status                    Comment status to limit results by. Accepts 'hold'
 236          *                                                   (`comment_status=0`), 'approve' (`comment_status=1`),
 237          *                                                   'all', or a custom comment status. Default 'all'.
 238          *     @type string|array $type                      Include comments of a given type, or array of types.
 239          *                                                   Accepts 'comment', 'pings' (includes 'pingback' and
 240          *                                                   'trackback'), or anycustom type string. Default empty.
 241          *     @type array        $type__in                  Include comments from a given array of comment types.
 242          *                                                   Default empty.
 243          *     @type array        $type__not_in              Exclude comments from a given array of comment types.
 244          *                                                   Default empty.
 245          *     @type int          $user_id                   Include comments for a specific user ID. Default empty.
 246          *     @type bool|string  $hierarchical              Whether to include comment descendants in the results.
 247          *                                                   'threaded' returns a tree, with each comment's children
 248          *                                                   stored in a `children` property on the `WP_Comment`
 249          *                                                   object. 'flat' returns a flat array of found comments plus
 250          *                                                   their children. Pass `false` to leave out descendants.
 251          *                                                   The parameter is ignored (forced to `false`) when
 252          *                                                   `$fields` is 'ids' or 'counts'. Accepts 'threaded',
 253          *                                                   'flat', or false. Default: false.
 254          *     @type string       $cache_domain              Unique cache key to be produced when this query is stored in
 255          *                                                   an object cache. Default is 'core'.
 256          *     @type bool         $update_comment_meta_cache Whether to prime the metadata cache for found comments.
 257          *                                                   Default true.
 258          *     @type bool         $update_comment_post_cache Whether to prime the cache for comment posts.
 259          *                                                   Default false.
 260          * }
 261          */
 262         public function __construct( $query = '' ) {
 263                 $this->query_var_defaults = array(
 264                         'author_email' => '',
 265                         'author_url' => '',
 266                         'author__in' => '',
 267                         'author__not_in' => '',
 268                         'include_unapproved' => '',
 269                         'fields' => '',
 270                         'ID' => '',
 271                         'comment__in' => '',
 272                         'comment__not_in' => '',
 273                         'karma' => '',
 274                         'number' => '',
 275                         'offset' => '',
 276                         'no_found_rows' => true,
 277                         'orderby' => '',
 278                         'order' => 'DESC',
 279                         'parent' => '',
 280                         'parent__in' => '',
 281                         'parent__not_in' => '',
 282                         'post_author__in' => '',
 283                         'post_author__not_in' => '',
 284                         'post_ID' => '',
 285                         'post_id' => 0,
 286                         'post__in' => '',
 287                         'post__not_in' => '',
 288                         'post_author' => '',
 289                         'post_name' => '',
 290                         'post_parent' => '',
 291                         'post_status' => '',
 292                         'post_type' => '',
 293                         'status' => 'all',
 294                         'type' => '',
 295                         'type__in' => '',
 296                         'type__not_in' => '',
 297                         'user_id' => '',
 298                         'search' => '',
 299                         'count' => false,
 300                         'meta_key' => '',
 301                         'meta_value' => '',
 302                         'meta_query' => '',
 303                         'date_query' => null, // See WP_Date_Query
 304                         'hierarchical' => false,
 305                         'cache_domain' => 'core',
 306                         'update_comment_meta_cache' => true,
 307                         'update_comment_post_cache' => false,
 308                 );
 309
 310                 if ( ! empty( $query ) ) {
 311                         $this->query( $query );
 312                 }
 313         }
 314
 315         /**
 316          * Parse arguments passed to the comment query with default query parameters.
 317          *
 318          * @since 4.2.0 Extracted from WP_Comment_Query::query().
 319          *
 320          * @access public
 321          *
 322          * @param string|array $query WP_Comment_Query arguments. See WP_Comment_Query::__construct()
 323          */
 324         public function parse_query( $query = '' ) {
 325                 if ( empty( $query ) ) {
 326                         $query = $this->query_vars;
 327                 }
 328
 329                 $this->query_vars = wp_parse_args( $query, $this->query_var_defaults );
 330
 331                 /**
 332                  * Fires after the comment query vars have been parsed.
 333                  *
 334                  * @since 4.2.0
 335                  *
 336                  * @param WP_Comment_Query &$this The WP_Comment_Query instance (passed by reference).
 337                  */
 338                 do_action_ref_array( 'parse_comment_query', array( &$this ) );
 339         }
 340
 341         /**
 342          * Sets up the WordPress query for retrieving comments.
 343          *
 344          * @since 3.1.0
 345          * @since 4.1.0 Introduced 'comment__in', 'comment__not_in', 'post_author__in',
 346          *              'post_author__not_in', 'author__in', 'author__not_in', 'post__in',
 347          *              'post__not_in', 'include_unapproved', 'type__in', and 'type__not_in'
 348          *              arguments to $query_vars.
 349          * @since 4.2.0 Moved parsing to WP_Comment_Query::parse_query().
 350          * @access public
 351          *
 352          * @param string|array $query Array or URL query string of parameters.
 353          * @return array|int List of comments, or number of comments when 'count' is passed as a query var.
 354          */
 355         public function query( $query ) {
 356                 $this->query_vars = wp_parse_args( $query );
 357                 return $this->get_comments();
 358         }
 359
 360         /**
 361          * Get a list of comments matching the query vars.
 362          *
 363          * @since 4.2.0
 364          * @access public
 365          *
 366          * @global wpdb $wpdb WordPress database abstraction object.
 367          *
 368          * @return int|array List of comments or number of found comments if `$count` argument is true.
 369          */
 370         public function get_comments() {
 371                 global $wpdb;
 372
 373                 $this->parse_query();
 374
 375                 // Parse meta query
 376                 $this->meta_query = new WP_Meta_Query();
 377                 $this->meta_query->parse_query_vars( $this->query_vars );
 378
 379                 /**
 380                  * Fires before comments are retrieved.
 381                  *
 382                  * @since 3.1.0
 383                  *
 384                  * @param WP_Comment_Query &$this Current instance of WP_Comment_Query, passed by reference.
 385                  */
 386                 do_action_ref_array( 'pre_get_comments', array( &$this ) );
 387
 388                 // Reparse query vars, in case they were modified in a 'pre_get_comments' callback.
 389                 $this->meta_query->parse_query_vars( $this->query_vars );
 390                 if ( ! empty( $this->meta_query->queries ) ) {
 391                         $this->meta_query_clauses = $this->meta_query->get_sql( 'comment', $wpdb->comments, 'comment_ID', $this );
 392                 }
 393
 394                 // $args can include anything. Only use the args defined in the query_var_defaults to compute the key.
 395                 $key = md5( serialize( wp_array_slice_assoc( $this->query_vars, array_keys( $this->query_var_defaults ) ) ) );
 396                 $last_changed = wp_cache_get( 'last_changed', 'comment' );
 397                 if ( ! $last_changed ) {
 398                         $last_changed = microtime();
 399                         wp_cache_set( 'last_changed', $last_changed, 'comment' );
 400                 }
 401
 402                 $cache_key   = "get_comments:$key:$last_changed";
 403                 $cache_value = wp_cache_get( $cache_key, 'comment' );
 404                 if ( false === $cache_value ) {
 405                         $comment_ids = $this->get_comment_ids();
 406                         if ( $comment_ids ) {
 407                                 $this->set_found_comments();
 408                         }
 409
 410                         $cache_value = array(
 411                                 'comment_ids'    => $comment_ids,
 412                                 'found_comments' => $this->found_comments,
 413                         );
 414                         wp_cache_add( $cache_key, $cache_value, 'comment' );
 415                 } else {
 416                         $comment_ids          = $cache_value['comment_ids'];
 417                         $this->found_comments = $cache_value['found_comments'];
 418                 }
 419
 420                 if ( $this->found_comments && $this->query_vars['number'] ) {
 421                         $this->max_num_pages = ceil( $this->found_comments / $this->query_vars['number'] );
 422                 }
 423
 424                 // If querying for a count only, there's nothing more to do.
 425                 if ( $this->query_vars['count'] ) {
 426                         // $comment_ids is actually a count in this case.
 427                         return intval( $comment_ids );
 428                 }
 429
 430                 $comment_ids = array_map( 'intval', $comment_ids );
 431
 432                 if ( 'ids' == $this->query_vars['fields'] ) {
 433                         $this->comments = $comment_ids;
 434                         return $this->comments;
 435                 }
 436
 437                 _prime_comment_caches( $comment_ids, $this->query_vars['update_comment_meta_cache'] );
 438
 439                 // Fetch full comment objects from the primed cache.
 440                 $_comments = array();
 441                 foreach ( $comment_ids as $comment_id ) {
 442                         if ( $_comment = get_comment( $comment_id ) ) {
 443                                 $_comments[] = $_comment;
 444                         }
 445                 }
 446
 447                 // Prime comment post caches.
 448                 if ( $this->query_vars['update_comment_post_cache'] ) {
 449                         $comment_post_ids = array();
 450                         foreach ( $_comments as $_comment ) {
 451                                 $comment_post_ids[] = $_comment->comment_post_ID;
 452                         }
 453
 454                         _prime_post_caches( $comment_post_ids, false, false );
 455                 }
 456
 457                 /**
 458                  * Filters the comment query results.
 459                  *
 460                  * @since 3.1.0
 461                  *
 462                  * @param array            $results  An array of comments.
 463                  * @param WP_Comment_Query &$this    Current instance of WP_Comment_Query, passed by reference.
 464                  */
 465                 $_comments = apply_filters_ref_array( 'the_comments', array( $_comments, &$this ) );
 466
 467                 // Convert to WP_Comment instances
 468                 $comments = array_map( 'get_comment', $_comments );
 469
 470                 if ( $this->query_vars['hierarchical'] ) {
 471                         $comments = $this->fill_descendants( $comments );
 472                 }
 473
 474                 $this->comments = $comments;
 475                 return $this->comments;
 476         }
 477
 478         /**
 479          * Used internally to get a list of comment IDs matching the query vars.
 480          *
 481          * @since 4.4.0
 482          * @access protected
 483          *
 484          * @global wpdb $wpdb WordPress database abstraction object.
 485          */
 486         protected function get_comment_ids() {
 487                 global $wpdb;
 488
 489                 // Assemble clauses related to 'comment_approved'.
 490                 $approved_clauses = array();
 491
 492                 // 'status' accepts an array or a comma-separated string.
 493                 $status_clauses = array();
 494                 $statuses = $this->query_vars['status'];
 495                 if ( ! is_array( $statuses ) ) {
 496                         $statuses = preg_split( '/[\s,]+/', $statuses );
 497                 }
 498
 499                 // 'any' overrides other statuses.
 500                 if ( ! in_array( 'any', $statuses ) ) {
 501                         foreach ( $statuses as $status ) {
 502                                 switch ( $status ) {
 503                                         case 'hold' :
 504                                                 $status_clauses[] = "comment_approved = '0'";
 505                                                 break;
 506
 507                                         case 'approve' :
 508                                                 $status_clauses[] = "comment_approved = '1'";
 509                                                 break;
 510
 511                                         case 'all' :
 512                                         case '' :
 513                                                 $status_clauses[] = "( comment_approved = '0' OR comment_approved = '1' )";
 514                                                 break;
 515
 516                                         default :
 517                                                 $status_clauses[] = $wpdb->prepare( "comment_approved = %s", $status );
 518                                                 break;
 519                                 }
 520                         }
 521
 522                         if ( ! empty( $status_clauses ) ) {
 523                                 $approved_clauses[] = '( ' . implode( ' OR ', $status_clauses ) . ' )';
 524                         }
 525                 }
 526
 527                 // User IDs or emails whose unapproved comments are included, regardless of $status.
 528                 if ( ! empty( $this->query_vars['include_unapproved'] ) ) {
 529                         $include_unapproved = $this->query_vars['include_unapproved'];
 530
 531                         // Accepts arrays or comma-separated strings.
 532                         if ( ! is_array( $include_unapproved ) ) {
 533                                 $include_unapproved = preg_split( '/[\s,]+/', $include_unapproved );
 534                         }
 535
 536                         $unapproved_ids = $unapproved_emails = array();
 537                         foreach ( $include_unapproved as $unapproved_identifier ) {
 538                                 // Numeric values are assumed to be user ids.
 539                                 if ( is_numeric( $unapproved_identifier ) ) {
 540                                         $approved_clauses[] = $wpdb->prepare( "( user_id = %d AND comment_approved = '0' )", $unapproved_identifier );
 541
 542                                 // Otherwise we match against email addresses.
 543                                 } else {
 544                                         $approved_clauses[] = $wpdb->prepare( "( comment_author_email = %s AND comment_approved = '0' )", $unapproved_identifier );
 545                                 }
 546                         }
 547                 }
 548
 549                 // Collapse comment_approved clauses into a single OR-separated clause.
 550                 if ( ! empty( $approved_clauses ) ) {
 551                         if ( 1 === count( $approved_clauses ) ) {
 552                                 $this->sql_clauses['where']['approved'] = $approved_clauses[0];
 553                         } else {
 554                                 $this->sql_clauses['where']['approved'] = '( ' . implode( ' OR ', $approved_clauses ) . ' )';
 555                         }
 556                 }
 557
 558                 $order = ( 'ASC' == strtoupper( $this->query_vars['order'] ) ) ? 'ASC' : 'DESC';
 559
 560                 // Disable ORDER BY with 'none', an empty array, or boolean false.
 561                 if ( in_array( $this->query_vars['orderby'], array( 'none', array(), false ), true ) ) {
 562                         $orderby = '';
 563                 } elseif ( ! empty( $this->query_vars['orderby'] ) ) {
 564                         $ordersby = is_array( $this->query_vars['orderby'] ) ?
 565                                 $this->query_vars['orderby'] :
 566                                 preg_split( '/[,\s]/', $this->query_vars['orderby'] );
 567
 568                         $orderby_array = array();
 569                         $found_orderby_comment_ID = false;
 570                         foreach ( $ordersby as $_key => $_value ) {
 571                                 if ( ! $_value ) {
 572                                         continue;
 573                                 }
 574
 575                                 if ( is_int( $_key ) ) {
 576                                         $_orderby = $_value;
 577                                         $_order = $order;
 578                                 } else {
 579                                         $_orderby = $_key;
 580                                         $_order = $_value;
 581                                 }
 582
 583                                 if ( ! $found_orderby_comment_ID && in_array( $_orderby, array( 'comment_ID', 'comment__in' ) ) ) {
 584                                         $found_orderby_comment_ID = true;
 585                                 }
 586
 587                                 $parsed = $this->parse_orderby( $_orderby );
 588
 589                                 if ( ! $parsed ) {
 590                                         continue;
 591                                 }
 592
 593                                 if ( 'comment__in' === $_orderby ) {
 594                                         $orderby_array[] = $parsed;
 595                                         continue;
 596                                 }
 597
 598                                 $orderby_array[] = $parsed . ' ' . $this->parse_order( $_order );
 599                         }
 600
 601                         // If no valid clauses were found, order by comment_date_gmt.
 602                         if ( empty( $orderby_array ) ) {
 603                                 $orderby_array[] = "$wpdb->comments.comment_date_gmt $order";
 604                         }
 605
 606                         // To ensure determinate sorting, always include a comment_ID clause.
 607                         if ( ! $found_orderby_comment_ID ) {
 608                                 $comment_ID_order = '';
 609
 610                                 // Inherit order from comment_date or comment_date_gmt, if available.
 611                                 foreach ( $orderby_array as $orderby_clause ) {
 612                                         if ( preg_match( '/comment_date(?:_gmt)*\ (ASC|DESC)/', $orderby_clause, $match ) ) {
 613                                                 $comment_ID_order = $match[1];
 614                                                 break;
 615                                         }
 616                                 }
 617
 618                                 // If no date-related order is available, use the date from the first available clause.
 619                                 if ( ! $comment_ID_order ) {
 620                                         foreach ( $orderby_array as $orderby_clause ) {
 621                                                 if ( false !== strpos( 'ASC', $orderby_clause ) ) {
 622                                                         $comment_ID_order = 'ASC';
 623                                                 } else {
 624                                                         $comment_ID_order = 'DESC';
 625                                                 }
 626
 627                                                 break;
 628                                         }
 629                                 }
 630
 631                                 // Default to DESC.
 632                                 if ( ! $comment_ID_order ) {
 633                                         $comment_ID_order = 'DESC';
 634                                 }
 635
 636                                 $orderby_array[] = "$wpdb->comments.comment_ID $comment_ID_order";
 637                         }
 638
 639                         $orderby = implode( ', ', $orderby_array );
 640                 } else {
 641                         $orderby = "$wpdb->comments.comment_date_gmt $order";
 642                 }
 643
 644                 $number = absint( $this->query_vars['number'] );
 645                 $offset = absint( $this->query_vars['offset'] );
 646
 647                 if ( ! empty( $number ) ) {
 648                         if ( $offset ) {
 649                                 $limits = 'LIMIT ' . $offset . ',' . $number;
 650                         } else {
 651                                 $limits = 'LIMIT ' . $number;
 652                         }
 653                 }
 654
 655                 if ( $this->query_vars['count'] ) {
 656                         $fields = 'COUNT(*)';
 657                 } else {
 658                         $fields = "$wpdb->comments.comment_ID";
 659                 }
 660
 661                 $post_id = absint( $this->query_vars['post_id'] );
 662                 if ( ! empty( $post_id ) ) {
 663                         $this->sql_clauses['where']['post_id'] = $wpdb->prepare( 'comment_post_ID = %d', $post_id );
 664                 }
 665
 666                 // Parse comment IDs for an IN clause.
 667                 if ( ! empty( $this->query_vars['comment__in'] ) ) {
 668                         $this->sql_clauses['where']['comment__in'] = "$wpdb->comments.comment_ID IN ( " . implode( ',', wp_parse_id_list( $this->query_vars['comment__in'] ) ) . ' )';
 669                 }
 670
 671                 // Parse comment IDs for a NOT IN clause.
 672                 if ( ! empty( $this->query_vars['comment__not_in'] ) ) {
 673                         $this->sql_clauses['where']['comment__not_in'] = "$wpdb->comments.comment_ID NOT IN ( " . implode( ',', wp_parse_id_list( $this->query_vars['comment__not_in'] ) ) . ' )';
 674                 }
 675
 676                 // Parse comment parent IDs for an IN clause.
 677                 if ( ! empty( $this->query_vars['parent__in'] ) ) {
 678                         $this->sql_clauses['where']['parent__in'] = 'comment_parent IN ( ' . implode( ',', wp_parse_id_list( $this->query_vars['parent__in'] ) ) . ' )';
 679                 }
 680
 681                 // Parse comment parent IDs for a NOT IN clause.
 682                 if ( ! empty( $this->query_vars['parent__not_in'] ) ) {
 683                         $this->sql_clauses['where']['parent__not_in'] = 'comment_parent NOT IN ( ' . implode( ',', wp_parse_id_list( $this->query_vars['parent__not_in'] ) ) . ' )';
 684                 }
 685
 686                 // Parse comment post IDs for an IN clause.
 687                 if ( ! empty( $this->query_vars['post__in'] ) ) {
 688                         $this->sql_clauses['where']['post__in'] = 'comment_post_ID IN ( ' . implode( ',', wp_parse_id_list( $this->query_vars['post__in'] ) ) . ' )';
 689                 }
 690
 691                 // Parse comment post IDs for a NOT IN clause.
 692                 if ( ! empty( $this->query_vars['post__not_in'] ) ) {
 693                         $this->sql_clauses['where']['post__not_in'] = 'comment_post_ID NOT IN ( ' . implode( ',', wp_parse_id_list( $this->query_vars['post__not_in'] ) ) . ' )';
 694                 }
 695
 696                 if ( '' !== $this->query_vars['author_email'] ) {
 697                         $this->sql_clauses['where']['author_email'] = $wpdb->prepare( 'comment_author_email = %s', $this->query_vars['author_email'] );
 698                 }
 699
 700                 if ( '' !== $this->query_vars['author_url'] ) {
 701                         $this->sql_clauses['where']['author_url'] = $wpdb->prepare( 'comment_author_url = %s', $this->query_vars['author_url'] );
 702                 }
 703
 704                 if ( '' !== $this->query_vars['karma'] ) {
 705                         $this->sql_clauses['where']['karma'] = $wpdb->prepare( 'comment_karma = %d', $this->query_vars['karma'] );
 706                 }
 707
 708                 // Filtering by comment_type: 'type', 'type__in', 'type__not_in'.
 709                 $raw_types = array(
 710                         'IN' => array_merge( (array) $this->query_vars['type'], (array) $this->query_vars['type__in'] ),
 711                         'NOT IN' => (array) $this->query_vars['type__not_in'],
 712                 );
 713
 714                 $comment_types = array();
 715                 foreach ( $raw_types as $operator => $_raw_types ) {
 716                         $_raw_types = array_unique( $_raw_types );
 717
 718                         foreach ( $_raw_types as $type ) {
 719                                 switch ( $type ) {
 720                                         // An empty translates to 'all', for backward compatibility
 721                                         case '':
 722                                         case 'all' :
 723                                                 break;
 724
 725                                         case 'comment':
 726                                         case 'comments':
 727                                                 $comment_types[ $operator ][] = "''";
 728                                                 break;
 729
 730                                         case 'pings':
 731                                                 $comment_types[ $operator ][] = "'pingback'";
 732                                                 $comment_types[ $operator ][] = "'trackback'";
 733                                                 break;
 734
 735                                         default:
 736                                                 $comment_types[ $operator ][] = $wpdb->prepare( '%s', $type );
 737                                                 break;
 738                                 }
 739                         }
 740
 741                         if ( ! empty( $comment_types[ $operator ] ) ) {
 742                                 $types_sql = implode( ', ', $comment_types[ $operator ] );
 743                                 $this->sql_clauses['where']['comment_type__' . strtolower( str_replace( ' ', '_', $operator ) ) ] = "comment_type $operator ($types_sql)";
 744                         }
 745                 }
 746
 747                 $parent = $this->query_vars['parent'];
 748                 if ( $this->query_vars['hierarchical'] && ! $parent ) {
 749                         $parent = 0;
 750                 }
 751
 752                 if ( '' !== $parent ) {
 753                         $this->sql_clauses['where']['parent'] = $wpdb->prepare( 'comment_parent = %d', $parent );
 754                 }
 755
 756                 if ( is_array( $this->query_vars['user_id'] ) ) {
 757                         $this->sql_clauses['where']['user_id'] = 'user_id IN (' . implode( ',', array_map( 'absint', $this->query_vars['user_id'] ) ) . ')';
 758                 } elseif ( '' !== $this->query_vars['user_id'] ) {
 759                         $this->sql_clauses['where']['user_id'] = $wpdb->prepare( 'user_id = %d', $this->query_vars['user_id'] );
 760                 }
 761
 762                 // Falsy search strings are ignored.
 763                 if ( strlen( $this->query_vars['search'] ) ) {
 764                         $search_sql = $this->get_search_sql(
 765                                 $this->query_vars['search'],
 766                                 array( 'comment_author', 'comment_author_email', 'comment_author_url', 'comment_author_IP', 'comment_content' )
 767                         );
 768
 769                         // Strip leading 'AND'.
 770                         $this->sql_clauses['where']['search'] = preg_replace( '/^\s*AND\s*/', '', $search_sql );
 771                 }
 772
 773                 // If any post-related query vars are passed, join the posts table.
 774                 $join_posts_table = false;
 775                 $plucked = wp_array_slice_assoc( $this->query_vars, array( 'post_author', 'post_name', 'post_parent' ) );
 776                 $post_fields = array_filter( $plucked );
 777
 778                 if ( ! empty( $post_fields ) ) {
 779                         $join_posts_table = true;
 780                         foreach ( $post_fields as $field_name => $field_value ) {
 781                                 // $field_value may be an array.
 782                                 $esses = array_fill( 0, count( (array) $field_value ), '%s' );
 783                                 $this->sql_clauses['where'][ $field_name ] = $wpdb->prepare( " {$wpdb->posts}.{$field_name} IN (" . implode( ',', $esses ) . ')', $field_value );
 784                         }
 785                 }
 786
 787                 // 'post_status' and 'post_type' are handled separately, due to the specialized behavior of 'any'.
 788                 foreach ( array( 'post_status', 'post_type' ) as $field_name ) {
 789                         $q_values = array();
 790                         if ( ! empty( $this->query_vars[ $field_name ] ) ) {
 791                                 $q_values = $this->query_vars[ $field_name ];
 792                                 if ( ! is_array( $q_values ) ) {
 793                                         $q_values = explode( ',', $q_values );
 794                                 }
 795
 796                                 // 'any' will cause the query var to be ignored.
 797                                 if ( in_array( 'any', $q_values, true ) || empty( $q_values ) ) {
 798                                         continue;
 799                                 }
 800
 801                                 $join_posts_table = true;
 802
 803                                 $esses = array_fill( 0, count( $q_values ), '%s' );
 804                                 $this->sql_clauses['where'][ $field_name ] = $wpdb->prepare( " {$wpdb->posts}.{$field_name} IN (" . implode( ',', $esses ) . ")", $q_values );
 805                         }
 806                 }
 807
 808                 // Comment author IDs for an IN clause.
 809                 if ( ! empty( $this->query_vars['author__in'] ) ) {
 810                         $this->sql_clauses['where']['author__in'] = 'user_id IN ( ' . implode( ',', wp_parse_id_list( $this->query_vars['author__in'] ) ) . ' )';
 811                 }
 812
 813                 // Comment author IDs for a NOT IN clause.
 814                 if ( ! empty( $this->query_vars['author__not_in'] ) ) {
 815                         $this->sql_clauses['where']['author__not_in'] = 'user_id NOT IN ( ' . implode( ',', wp_parse_id_list( $this->query_vars['author__not_in'] ) ) . ' )';
 816                 }
 817
 818                 // Post author IDs for an IN clause.
 819                 if ( ! empty( $this->query_vars['post_author__in'] ) ) {
 820                         $join_posts_table = true;
 821                         $this->sql_clauses['where']['post_author__in'] = 'post_author IN ( ' . implode( ',', wp_parse_id_list( $this->query_vars['post_author__in'] ) ) . ' )';
 822                 }
 823
 824                 // Post author IDs for a NOT IN clause.
 825                 if ( ! empty( $this->query_vars['post_author__not_in'] ) ) {
 826                         $join_posts_table = true;
 827                         $this->sql_clauses['where']['post_author__not_in'] = 'post_author NOT IN ( ' . implode( ',', wp_parse_id_list( $this->query_vars['post_author__not_in'] ) ) . ' )';
 828                 }
 829
 830                 $join = '';
 831
 832                 if ( $join_posts_table ) {
 833                         $join .= "JOIN $wpdb->posts ON $wpdb->posts.ID = $wpdb->comments.comment_post_ID";
 834                 }
 835
 836                 if ( ! empty( $this->meta_query_clauses ) ) {
 837                         $join .= $this->meta_query_clauses['join'];
 838
 839                         // Strip leading 'AND'.
 840                         $this->sql_clauses['where']['meta_query'] = preg_replace( '/^\s*AND\s*/', '', $this->meta_query_clauses['where'] );
 841
 842                         if ( ! $this->query_vars['count'] ) {
 843                                 $groupby = "{$wpdb->comments}.comment_ID";
 844                         }
 845                 }
 846
 847                 if ( ! empty( $this->query_vars['date_query'] ) && is_array( $this->query_vars['date_query'] ) ) {
 848                         $this->date_query = new WP_Date_Query( $this->query_vars['date_query'], 'comment_date' );
 849                         $this->sql_clauses['where']['date_query'] = preg_replace( '/^\s*AND\s*/', '', $this->date_query->get_sql() );
 850                 }
 851
 852                 $where = implode( ' AND ', $this->sql_clauses['where'] );
 853
 854                 $pieces = array( 'fields', 'join', 'where', 'orderby', 'limits', 'groupby' );
 855                 /**
 856                  * Filters the comment query clauses.
 857                  *
 858                  * @since 3.1.0
 859                  *
 860                  * @param array            $pieces A compacted array of comment query clauses.
 861                  * @param WP_Comment_Query &$this  Current instance of WP_Comment_Query, passed by reference.
 862                  */
 863                 $clauses = apply_filters_ref_array( 'comments_clauses', array( compact( $pieces ), &$this ) );
 864
 865                 $fields = isset( $clauses[ 'fields' ] ) ? $clauses[ 'fields' ] : '';
 866                 $join = isset( $clauses[ 'join' ] ) ? $clauses[ 'join' ] : '';
 867                 $where = isset( $clauses[ 'where' ] ) ? $clauses[ 'where' ] : '';
 868                 $orderby = isset( $clauses[ 'orderby' ] ) ? $clauses[ 'orderby' ] : '';
 869                 $limits = isset( $clauses[ 'limits' ] ) ? $clauses[ 'limits' ] : '';
 870                 $groupby = isset( $clauses[ 'groupby' ] ) ? $clauses[ 'groupby' ] : '';
 871
 872                 $this->filtered_where_clause = $where;
 873
 874                 if ( $where ) {
 875                         $where = 'WHERE ' . $where;
 876                 }
 877
 878                 if ( $groupby ) {
 879                         $groupby = 'GROUP BY ' . $groupby;
 880                 }
 881
 882                 if ( $orderby ) {
 883                         $orderby = "ORDER BY $orderby";
 884                 }
 885
 886                 $found_rows = '';
 887                 if ( ! $this->query_vars['no_found_rows'] ) {
 888                         $found_rows = 'SQL_CALC_FOUND_ROWS';
 889                 }
 890
 891                 $this->sql_clauses['select']  = "SELECT $found_rows $fields";
 892                 $this->sql_clauses['from']    = "FROM $wpdb->comments $join";
 893                 $this->sql_clauses['groupby'] = $groupby;
 894                 $this->sql_clauses['orderby'] = $orderby;
 895                 $this->sql_clauses['limits']  = $limits;
 896
 897                 $this->request = "{$this->sql_clauses['select']} {$this->sql_clauses['from']} {$where} {$this->sql_clauses['groupby']} {$this->sql_clauses['orderby']} {$this->sql_clauses['limits']}";
 898
 899                 if ( $this->query_vars['count'] ) {
 900                         return intval( $wpdb->get_var( $this->request ) );
 901                 } else {
 902                         $comment_ids = $wpdb->get_col( $this->request );
 903                         return array_map( 'intval', $comment_ids );
 904                 }
 905         }
 906
 907         /**
 908          * Populates found_comments and max_num_pages properties for the current
 909          * query if the limit clause was used.
 910          *
 911          * @since 4.6.0
 912          * @access private
 913          *
 914          * @global wpdb $wpdb WordPress database abstraction object.
 915          */
 916         private function set_found_comments() {
 917                 global $wpdb;
 918
 919                 if ( $this->query_vars['number'] && ! $this->query_vars['no_found_rows'] ) {
 920                         /**
 921                          * Filters the query used to retrieve found comment count.
 922                          *
 923                          * @since 4.4.0
 924                          *
 925                          * @param string           $found_comments_query SQL query. Default 'SELECT FOUND_ROWS()'.
 926                          * @param WP_Comment_Query $comment_query        The `WP_Comment_Query` instance.
 927                          */
 928                         $found_comments_query = apply_filters( 'found_comments_query', 'SELECT FOUND_ROWS()', $this );
 929
 930                         $this->found_comments = (int) $wpdb->get_var( $found_comments_query );
 931                 }
 932         }
 933
 934         /**
 935          * Fetch descendants for located comments.
 936          *
 937          * Instead of calling `get_children()` separately on each child comment, we do a single set of queries to fetch
 938          * the descendant trees for all matched top-level comments.
 939          *
 940          * @since 4.4.0
 941          *
 942          * @param array $comments Array of top-level comments whose descendants should be filled in.
 943          * @return array
 944          */
 945         protected function fill_descendants( $comments ) {
 946                 global $wpdb;
 947
 948                 $levels = array(
 949                         0 => wp_list_pluck( $comments, 'comment_ID' ),
 950                 );
 951
 952                 /*
 953                  * The WHERE clause for the descendant query is the same as for the top-level
 954                  * query, minus the `parent`, `parent__in`, and `parent__not_in` sub-clauses.
 955                  */
 956                 $_where = $this->filtered_where_clause;
 957                 $exclude_keys = array( 'parent', 'parent__in', 'parent__not_in' );
 958                 foreach ( $exclude_keys as $exclude_key ) {
 959                         if ( isset( $this->sql_clauses['where'][ $exclude_key ] ) ) {
 960                                 $clause = $this->sql_clauses['where'][ $exclude_key ];
 961
 962                                 // Strip the clause as well as any adjacent ANDs.
 963                                 $pattern = '|(?:AND)?\s*' . $clause . '\s*(?:AND)?|';
 964                                 $_where_parts = preg_split( $pattern, $_where );
 965
 966                                 // Remove empties.
 967                                 $_where_parts = array_filter( array_map( 'trim', $_where_parts ) );
 968
 969                                 // Reassemble with an AND.
 970                                 $_where = implode( ' AND ', $_where_parts );
 971                         }
 972                 }
 973
 974                 $key = md5( serialize( wp_array_slice_assoc( $this->query_vars, array_keys( $this->query_var_defaults ) ) ) );
 975                 $last_changed = wp_cache_get( 'last_changed', 'comment' );
 976                 if ( ! $last_changed ) {
 977                         $last_changed = microtime();
 978                         wp_cache_set( 'last_changed', $last_changed, 'comment' );
 979                 }
 980
 981                 // Fetch an entire level of the descendant tree at a time.
 982                 $level = 0;
 983                 do {
 984                         // Parent-child relationships may be cached. Only query for those that are not.
 985                         $child_ids = $uncached_parent_ids = array();
 986                         $_parent_ids = $levels[ $level ];
 987                         foreach ( $_parent_ids as $parent_id ) {
 988                                 $cache_key = "get_comment_child_ids:$parent_id:$key:$last_changed";
 989                                 $parent_child_ids = wp_cache_get( $cache_key, 'comment' );
 990                                 if ( false !== $parent_child_ids ) {
 991                                         $child_ids = array_merge( $child_ids, $parent_child_ids );
 992                                 } else {
 993                                         $uncached_parent_ids[] = $parent_id;
 994                                 }
 995                         }
 996
 997                         if ( $uncached_parent_ids ) {
 998                                 $where = 'WHERE ' . $_where . ' AND comment_parent IN (' . implode( ',', array_map( 'intval', $uncached_parent_ids ) ) . ')';
 999                                 $level_comments = $wpdb->get_results( "SELECT $wpdb->comments.comment_ID, $wpdb->comments.comment_parent {$this->sql_clauses['from']} {$where} {$this->sql_clauses['groupby']} ORDER BY comment_date_gmt ASC, comment_ID ASC" );
1000
1001                                 // Cache parent-child relationships.
1002                                 $parent_map = array_fill_keys( $uncached_parent_ids, array() );
1003                                 foreach ( $level_comments as $level_comment ) {
1004                                         $parent_map[ $level_comment->comment_parent ][] = $level_comment->comment_ID;
1005                                         $child_ids[] = $level_comment->comment_ID;
1006                                 }
1007
1008                                 foreach ( $parent_map as $parent_id => $children ) {
1009                                         $cache_key = "get_comment_child_ids:$parent_id:$key:$last_changed";
1010                                         wp_cache_set( $cache_key, $children, 'comment' );
1011                                 }
1012                         }
1013
1014                         $level++;
1015                         $levels[ $level ] = $child_ids;
1016                 } while ( $child_ids );
1017
1018                 // Prime comment caches for non-top-level comments.
1019                 $descendant_ids = array();
1020                 for ( $i = 1; $i < count( $levels ); $i++ ) {
1021                         $descendant_ids = array_merge( $descendant_ids, $levels[ $i ] );
1022                 }
1023
1024                 _prime_comment_caches( $descendant_ids, $this->query_vars['update_comment_meta_cache'] );
1025
1026                 // Assemble a flat array of all comments + descendants.
1027                 $all_comments = $comments;
1028                 foreach ( $descendant_ids as $descendant_id ) {
1029                         $all_comments[] = get_comment( $descendant_id );
1030                 }
1031
1032                 // If a threaded representation was requested, build the tree.
1033                 if ( 'threaded' === $this->query_vars['hierarchical'] ) {
1034                         $threaded_comments = $ref = array();
1035                         foreach ( $all_comments as $k => $c ) {
1036                                 $_c = get_comment( $c->comment_ID );
1037
1038                                 // If the comment isn't in the reference array, it goes in the top level of the thread.
1039                                 if ( ! isset( $ref[ $c->comment_parent ] ) ) {
1040                                         $threaded_comments[ $_c->comment_ID ] = $_c;
1041                                         $ref[ $_c->comment_ID ] = $threaded_comments[ $_c->comment_ID ];
1042
1043                                 // Otherwise, set it as a child of its parent.
1044                                 } else {
1045
1046                                         $ref[ $_c->comment_parent ]->add_child( $_c );
1047                                         $ref[ $_c->comment_ID ] = $ref[ $_c->comment_parent ]->get_child( $_c->comment_ID );
1048                                 }
1049                         }
1050
1051                         // Set the 'populated_children' flag, to ensure additional database queries aren't run.
1052                         foreach ( $ref as $_ref ) {
1053                                 $_ref->populated_children( true );
1054                         }
1055
1056                         $comments = $threaded_comments;
1057                 } else {
1058                         $comments = $all_comments;
1059                 }
1060
1061                 return $comments;
1062         }
1063
1064         /**
1065          * Used internally to generate an SQL string for searching across multiple columns
1066          *
1067          * @since 3.1.0
1068          * @access protected
1069          *
1070          * @global wpdb $wpdb WordPress database abstraction object.
1071          *
1072          * @param string $string
1073          * @param array $cols
1074          * @return string
1075          */
1076         protected function get_search_sql( $string, $cols ) {
1077                 global $wpdb;
1078
1079                 $like = '%' . $wpdb->esc_like( $string ) . '%';
1080
1081                 $searches = array();
1082                 foreach ( $cols as $col ) {
1083                         $searches[] = $wpdb->prepare( "$col LIKE %s", $like );
1084                 }
1085
1086                 return ' AND (' . implode(' OR ', $searches) . ')';
1087         }
1088
1089         /**
1090          * Parse and sanitize 'orderby' keys passed to the comment query.
1091          *
1092          * @since 4.2.0
1093          * @access protected
1094          *
1095          * @global wpdb $wpdb WordPress database abstraction object.
1096          *
1097          * @param string $orderby Alias for the field to order by.
1098          * @return string|false Value to used in the ORDER clause. False otherwise.
1099          */
1100         protected function parse_orderby( $orderby ) {
1101                 global $wpdb;
1102
1103                 $allowed_keys = array(
1104                         'comment_agent',
1105                         'comment_approved',
1106                         'comment_author',
1107                         'comment_author_email',
1108                         'comment_author_IP',
1109                         'comment_author_url',
1110                         'comment_content',
1111                         'comment_date',
1112                         'comment_date_gmt',
1113                         'comment_ID',
1114                         'comment_karma',
1115                         'comment_parent',
1116                         'comment_post_ID',
1117                         'comment_type',
1118                         'user_id',
1119                 );
1120
1121                 if ( ! empty( $this->query_vars['meta_key'] ) ) {
1122                         $allowed_keys[] = $this->query_vars['meta_key'];
1123                         $allowed_keys[] = 'meta_value';
1124                         $allowed_keys[] = 'meta_value_num';
1125                 }
1126
1127                 $meta_query_clauses = $this->meta_query->get_clauses();
1128                 if ( $meta_query_clauses ) {
1129                         $allowed_keys = array_merge( $allowed_keys, array_keys( $meta_query_clauses ) );
1130                 }
1131
1132                 $parsed = false;
1133                 if ( $orderby == $this->query_vars['meta_key'] || $orderby == 'meta_value' ) {
1134                         $parsed = "$wpdb->commentmeta.meta_value";
1135                 } elseif ( $orderby == 'meta_value_num' ) {
1136                         $parsed = "$wpdb->commentmeta.meta_value+0";
1137                 } elseif ( $orderby == 'comment__in' ) {
1138                         $comment__in = implode( ',', array_map( 'absint', $this->query_vars['comment__in'] ) );
1139                         $parsed = "FIELD( {$wpdb->comments}.comment_ID, $comment__in )";
1140                 } elseif ( in_array( $orderby, $allowed_keys ) ) {
1141
1142                         if ( isset( $meta_query_clauses[ $orderby ] ) ) {
1143                                 $meta_clause = $meta_query_clauses[ $orderby ];
1144                                 $parsed = sprintf( "CAST(%s.meta_value AS %s)", esc_sql( $meta_clause['alias'] ), esc_sql( $meta_clause['cast'] ) );
1145                         } else {
1146                                 $parsed = "$wpdb->comments.$orderby";
1147                         }
1148                 }
1149
1150                 return $parsed;
1151         }
1152
1153         /**
1154          * Parse an 'order' query variable and cast it to ASC or DESC as necessary.
1155          *
1156          * @since 4.2.0
1157          * @access protected
1158          *
1159          * @param string $order The 'order' query variable.
1160          * @return string The sanitized 'order' query variable.
1161          */
1162         protected function parse_order( $order ) {
1163                 if ( ! is_string( $order ) || empty( $order ) ) {
1164                         return 'DESC';
1165                 }
1166
1167                 if ( 'ASC' === strtoupper( $order ) ) {
1168                         return 'ASC';
1169                 } else {
1170                         return 'DESC';
1171                 }
1172         }
1173 }