表A:id hynum hycount
1 101 0
2 102 0
3 103 0
....表B:id hynumber rebuy1 102 50
2 103 50
3 105 30需要实现:把B中的rebuy 导入A中对应的hycount. 条件:b.hynumber=a.hynum
1 101 0
2 102 0
3 103 0
....表B:id hynumber rebuy1 102 50
2 103 50
3 105 30需要实现:把B中的rebuy 导入A中对应的hycount. 条件:b.hynumber=a.hynum
set a.hycount=b.rebuy
from a inner join b on b.hynumber=a.hynum
set a.hycount=b.rebuy
from 表A a inner join 表B b on b.hynumber=a.hynum
from a,b
where a.hynum=b.hynumber