select dh , yf, qs, dqbh from t group by dh , yf, qs, dqbh having count(*)>1
select * from t as a join ( select dh , yf, qs, dqbh from t group by dh , yf, qs, dqbh having count(*)>1 ) as b on a.dh=b.dh and a.yf=b.yf and a.qs=b.qs and a.dqbh=b.dqbh
You have an error in your SQL syntax near '( select dh , yf, qs, dqbh from jk_kf_2004 group by dh , yf, qs, dqbh having cou' at line 1
from t
group by dh , yf, qs, dqbh
having count(*)>1
select dh , yf, qs, dqbh
from t
group by dh , yf, qs, dqbh
having count(*)>1
) as b
on a.dh=b.dh and a.yf=b.yf and a.qs=b.qs and a.dqbh=b.dqbh