java如何从mongoDB中按键名检索值?
我是mongoDB的新手。我正在使用java和mongoDB。我有一个类似json的
[{ "_id" : { "$oid" : "4ceb753a70fdf877ef5113ca"} , "HomeTown" : "AA" ,
"PhoneNumber" : { "CustName" : "xxx" , "Number" : "3403290"},
"MobileNumber" : { "CustName" : "yyy" , "Number" : "9323304302"}}]
[{ "_id" : { "$oid" : "4ceb753a70fdf877ef5113ca"} , "HomeTown" : "AA" ,
"PhoneNumber" : { "CustName" : "xxx" , "Number" : "3403290"},
"MobileNumber" : { "CustName" : "yyy" , "Number" : "9323304302"}}]
[{ "_id" : { "$oid" : "4ceb753a70fdf877ef5113ca"} , "HomeTown" : "BB" ,
"PhoneNumber" : { "CustName" : "xxx" , "Number" : "3403290"},
"MobileNumber" : { "CustName" : "yyy" , "Number" : "9323304302"}}]
[{ "_id" : { "$oid" : "4ceb753a70fdf877ef5113ca"} , "HomeTown" : "BB" ,
"PhoneNumber" : { "CustName" : "xxx" , "Number" : "3403290"},
"MobileNumber" : { "CustName" : "yyy" , "Number" : "9323304302"}}]
在一个集合中,所有文档都有不同的HomeTown
,我只知道键名HomeTown
,如何获得HomeTown
值
在mongo网站上,我只能找到find()
和findOne()
谢谢
# 1 楼答案
find()
就足够了在java中,它将是:
# 2 楼答案
这可能是错误的,但是
这是正确的,因为您需要显式地抑制
_id
。仅供参考# 3 楼答案
# 4 楼答案