mongodb自带的map/reduce跟hadoop的有什么关联吗?# Java - 爪哇娇娃
r*h
1 楼
id value
1 a
1 b
1 c
want something like
id value
1 a,b,c
Any single SQL statement can do this? (MySQL doesn't count...)
Thanks.
1 a
1 b
1 c
want something like
id value
1 a,b,c
Any single SQL statement can do this? (MySQL doesn't count...)
Thanks.