src/Query/FluentQuery.php
protected function update_meta_cache() {

		$ids       = $this->results->getKeys();
		$table     = $this->meta_table ?: call_user_func( array( $this->model, 'get_meta_table' ) );
		$meta_type = $this->meta_type ?: call_user_func( array( $this->model, 'get_meta_type' ) );

		$fn = function ( $key, $original ) use ( $table, $meta_type ) {

			if ( $original === $meta_type . '_id' ) {
				$key = $table->get_primary_id_column();
			}

			return $key;
		};

		add_filter( 'sanitize_key', $fn, 10, 2 );

		update_meta_cache( $meta_type, $ids );

		remove_filter( 'sanitize_key', $fn );
	}
protected function update_meta_cache() {

		$ids       = $this->results->getKeys();
		$table     = $this->meta_table ?: call_user_func( array( $this->model, 'get_meta_table' ) );
		$meta_type = $this->meta_type ?: call_user_func( array( $this->model, 'get_meta_type' ) );

		$fn = function ( $key, $original ) use ( $table, $meta_type ) {

			if ( $original === $meta_type . '_id' ) {
				$key = $table->get_primary_id_column();
			}

			return $key;
		};

		add_filter( 'sanitize_key', $fn, 10, 2 );

		update_meta_cache( $meta_type, $ids );

		remove_filter( 'sanitize_key', $fn );
	}
Update the meta cache.

@since 2.0