如果只要求生日一样就行的话。用下面的sql
update a,(select name,tel,dob from a
group by name,tel) t1
set a.dob = t1.dob
where a.name = t1.name
and a.tel = t1.tel
update a,(select name,tel,dob from a
group by name,tel) t1
set a.dob = t1.dob
where a.name = t1.name
and a.tel = t1.tel
update a表 v, (select id,max(dob) as d from a表 where dob!='0000-00-00' group by id) u
set v.dob=u.d
where v.dob='0000-00-00'