wpdb::_escape PHP Method

    function _escape($data)
    {
        if (is_array($data)) {
            foreach ($data as $k => $v) {
                if (is_array($v)) {
                    $data[$k] = $this->_escape($v);
                } else {
                    $data[$k] = $this->_real_escape($v);
                }
            }
        } else {
            $data = $this->_real_escape($data);
        }
        return $data;
    }

 /**
  * Used internally to get a list of network IDs matching the query vars.
  *
  * @since 4.6.0
  * @access protected
  *
  * @return int|array A single count of network IDs if a count query. An array of network IDs if a full query.
  */
 protected function get_network_ids()
 {
     $order = $this->parse_order($this->query_vars['order']);
     // Disable ORDER BY with 'none', an empty array, or boolean false.
     if (in_array($this->query_vars['orderby'], array('none', array(), false), true)) {
         $orderby = '';
     } elseif (!empty($this->query_vars['orderby'])) {
         $ordersby = is_array($this->query_vars['orderby']) ? $this->query_vars['orderby'] : preg_split('/[,\\s]/', $this->query_vars['orderby']);
         $orderby_array = array();
         foreach ($ordersby as $_key => $_value) {
             if (!$_value) {
                 continue;
             }
             if (is_int($_key)) {
                 $_orderby = $_value;
                 $_order = $order;
             } else {
                 $_orderby = $_key;
                 $_order = $_value;
             }
             $parsed = $this->parse_orderby($_orderby);
             if (!$parsed) {
                 continue;
             }
             if ('network__in' === $_orderby) {
                 $orderby_array[] = $parsed;
                 continue;
             }
             $orderby_array[] = $parsed . ' ' . $this->parse_order($_order);
         }
         $orderby = implode(', ', $orderby_array);
     } else {
         $orderby = "{$this->db->site}.id {$order}";
     }
     $number = absint($this->query_vars['number']);
     $offset = absint($this->query_vars['offset']);
     if (!empty($number)) {
         if ($offset) {
             $limits = 'LIMIT ' . $offset . ',' . $number;
         } else {
             $limits = 'LIMIT ' . $number;
         }
     }
     if ($this->query_vars['count']) {
         $fields = 'COUNT(*)';
     } else {
         $fields = "{$this->db->site}.id";
     }
     // Parse network IDs for an IN clause.
     if (!empty($this->query_vars['network__in'])) {
         $this->sql_clauses['where']['network__in'] = "{$this->db->site}.id IN ( " . implode(',', wp_parse_id_list($this->query_vars['network__in'])) . ' )';
     }
     // Parse network IDs for a NOT IN clause.
     if (!empty($this->query_vars['network__not_in'])) {
         $this->sql_clauses['where']['network__not_in'] = "{$this->db->site}.id NOT IN ( " . implode(',', wp_parse_id_list($this->query_vars['network__not_in'])) . ' )';
     }
     if (!empty($this->query_vars['domain'])) {
         $this->sql_clauses['where']['domain'] = $this->db->prepare("{$this->db->site}.domain = %s", $this->query_vars['domain']);
     }
     // Parse network domain for an IN clause.
     if (is_array($this->query_vars['domain__in'])) {
         $this->sql_clauses['where']['domain__in'] = "{$this->db->site}.domain IN ( '" . implode("', '", $this->db->_escape($this->query_vars['domain__in'])) . "' )";
     }
     // Parse network domain for a NOT IN clause.
     if (is_array($this->query_vars['domain__not_in'])) {
         $this->sql_clauses['where']['domain__not_in'] = "{$this->db->site}.domain NOT IN ( '" . implode("', '", $this->db->_escape($this->query_vars['domain__not_in'])) . "' )";
     }
     if (!empty($this->query_vars['path'])) {
         $this->sql_clauses['where']['path'] = $this->db->prepare("{$this->db->site}.path = %s", $this->query_vars['path']);
     }
     // Parse network path for an IN clause.
     if (is_array($this->query_vars['path__in'])) {
         $this->sql_clauses['where']['path__in'] = "{$this->db->site}.path IN ( '" . implode("', '", $this->db->_escape($this->query_vars['path__in'])) . "' )";
     }
     // Parse network path for a NOT IN clause.
     if (is_array($this->query_vars['path__not_in'])) {
         $this->sql_clauses['where']['path__not_in'] = "{$this->db->site}.path NOT IN ( '" . implode("', '", $this->db->_escape($this->query_vars['path__not_in'])) . "' )";
     }
     // Falsey search strings are ignored.
     if (strlen($this->query_vars['search'])) {
         $this->sql_clauses['where']['search'] = $this->get_search_sql($this->query_vars['search'], array("{$this->db->site}.domain", "{$this->db->site}.path"));
     }
     $join = '';
     $where = implode(' AND ', $this->sql_clauses['where']);
     $pieces = array('fields', 'join', 'where', 'orderby', 'limits', 'groupby');
     /**
      * Filters the network query clauses.
      *
      * @since 4.6.0
      *
      * @param array            $pieces A compacted array of network query clauses.
      * @param WP_Network_Query &$this  Current instance of WP_Network_Query, passed by reference.
      */
     $clauses = apply_filters_ref_array('networks_clauses', array(compact($pieces), &$this));
     $fields = isset($clauses['fields']) ? $clauses['fields'] : '';
     $join = isset($clauses['join']) ? $clauses['join'] : '';
     $where = isset($clauses['where']) ? $clauses['where'] : '';
     $orderby = isset($clauses['orderby']) ? $clauses['orderby'] : '';
     $limits = isset($clauses['limits']) ? $clauses['limits'] : '';
     $groupby = isset($clauses['groupby']) ? $clauses['groupby'] : '';
     if ($where) {
         $where = 'WHERE ' . $where;
     }
     if ($groupby) {
         $groupby = 'GROUP BY ' . $groupby;
     }
     if ($orderby) {
         $orderby = "ORDER BY {$orderby}";
     }
     $found_rows = '';
     if (!$this->query_vars['no_found_rows']) {
         $found_rows = 'SQL_CALC_FOUND_ROWS';
     }
     $this->sql_clauses['select'] = "SELECT {$found_rows} {$fields}";
     $this->sql_clauses['from'] = "FROM {$this->db->site} {$join}";
     $this->sql_clauses['groupby'] = $groupby;
     $this->sql_clauses['orderby'] = $orderby;
     $this->sql_clauses['limits'] = $limits;
     $this->request = "{$this->sql_clauses['select']} {$this->sql_clauses['from']} {$where} {$this->sql_clauses['groupby']} {$this->sql_clauses['orderby']} {$this->sql_clauses['limits']}";
     if ($this->query_vars['count']) {
         return intval($this->db->get_var($this->request));
     }
     $network_ids = $this->db->get_col($this->request);
     return array_map('intval', $network_ids);
 }