Trigger to reset auto increment after the table empty

[Rusdy Perkasa]

hi, i am new to mysql and is processsing to migrate from firebird to mysql.
can anyone help me create for my case
i want to create trigger
to reset autoincrement after emptying row on table
and this trigger event is on delete row
this my trigger syntax on firebird :

DECLARE VARIABLE L_VARIABLE INTEGER;
BEGIN
SELECT FIRST 1
ID
FROM
JENISJURNAL
INTO
:L_VARIABLE;

IF (L_VARIABLE IS NULL) THEN
EXECUTE STATEMENT 'ALTER SEQUENCE GEN_JENISJURNAL_ID RESTART WITH 0';
END;

i already try on mysql but always show error

thx