public function query( $args = array(), $return_type = 'OBJECT' ) {
		global $wpdb;

		$args = wp_parse_args( $args, array(
			'fields'  => '*',
			'page'    => null,
			'limit'   => null,
			'offset'  => null,
			's'       => null,
			'orderby' => null,
			'order'   => null,
		) );

		$columns = $this->get_columns();

		$fields = $args['fields'];

		if ( $fields == '*' ) {
			$fields = array_keys( $columns );
		} else {
			$fields = explode( ',', $args['fields'] );
			$fields = array_map( 'trim', $fields );
			$fields = array_map( 'sanitize_text_field', $fields );
		}

		$select_fields = implode( '`, `', $fields );

		// Begin building query.
		$query = "SELECT `$select_fields` FROM {$this->table_name()}";

		// Set up $values array for wpdb::prepare
		$values = array();

		// Define an empty WHERE clause to start from.
		$where = "WHERE 1=1";

		// Build search query.
		if ( $args['s'] && ! empty( $args['s'] ) ) {

			$search = wp_unslash( trim( $args['s'] ) );

			$search_where = array();

			foreach ( $columns as $key => $type ) {
				if ( in_array( $key, $fields ) ) {
					if ( $type == '%s' || ( $type == '%d' && is_numeric( $search ) ) ) {
						$values[]       = '%' . $wpdb->esc_like( $search ) . '%';
						$search_where[] = "`$key` LIKE '%s'";
					}
				}
			}

			if ( ! empty( $search_where ) ) {
				$where .= ' AND (' . join( ' OR ', $search_where ) . ')';
			}
		}

		$query .= " $where";

		if ( ! empty( $args['orderby'] ) ) {
			$query    .= " ORDER BY %s";
			$values[] = wp_unslash( trim( $args['orderby'] ) );

			switch ( $args['order'] ) {
				case 'asc':
				case 'ASC':
					$query .= " ASC";
					break;
				case 'desc':
				case 'DESC':
				default:
					$query .= " DESC";
					break;
			}
		}

		if ( ! empty( $args['limit'] ) ) {
			$query    .= " LIMIT %d";
			$values[] = absint( $args['limit'] );
		}

		// Pagination.
		if ( $args['page'] >= 1 ) {
			$args['offset'] = ( $args['page'] * $args['limit'] ) - $args['limit'];
		}

		if ( ! empty( $args['offset'] ) ) {
			$query    .= " OFFSET %d";
			$values[] = absint( $args['offset'] );
		}

		if ( strpos( $query, '%s' ) || strpos( $query, '%d' ) ) {
			$query = $wpdb->prepare( $query, $values );
		}

		return $wpdb->get_results( $query, $return_type );
	}