HI,ALL
Anyone know Access sql statement , use left join 3 tables, and group by , having sum function...
How can write to work, thx?

select distinct (c.candidate_no) FROM ((candidate as c left JOIN education as e ON c.candidate_no = e.candidate_no )
left Join working as w ON c.candidate_no = w.candidate_no )group by c.candidate_no
having sum(datediff('yyyy','01/01/' & w.from_year ,'01/01/' & w.to_year )) >= 1

tablename: Candidate
----------------------------------

candidate_id char(key)
candidate_no char

tablename: Education
----------------------------------
education_id char(key)
candidate_no char

tablename: Working
----------------------------------
working_id char(key)
candidate_no char
from_year int
to_year int