DELIMITER $$
CREATE PROCEDURE my_procedure()
BEGIN
SET @OutputPath := '/var/www/html/tmp';
SET @fullOutputPath := CONCAT(@OutputPath,'/',now());
set @q1 := concat("SELECT * INTO OUTFILE '",@fullOutputPath,"' FROM my_table");
prepare s1 from @q1;
execute s1;deallocate prepare s1;
END $$
DELIMITER ;
And Call my_procedure() in trigger
DELIMITER $$
CREATE
TRIGGER my_trigger
AFTER INSERT ON my_table2
FOR EACH ROW
BEGIN
CALL my_procedure();
END
$$
DELIMITER;