本文介绍了如何通过密钥名称从mongoDB中检索值?的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我是mongoDB的新手。我正在使用java和mongoDB。我有一个json,
I am new to mongoDB. I am using java and mongoDB. I have a json like,
[{ "_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"}}]在集合中所有文档 s有不同的 HomeTown ,我只知道密钥名称 HomeTown ,我怎么能得到 HomeTown 值?
In a collection all doc's have different HomeTown, i just know the key name HomeTown, how can i get the HomeTown values?
在mongo网站中,我只能找到 find()和 findOne()。
In mongo site, i just can find find() and findOne().
谢谢!
推荐答案find( )就足够了。
db.CollectionName.find({},{HomeTown:1})在java中,它将是:
in java, it would be:
BasicDBObject query = new BasicDBObject(); BasicDBObject field = new BasicDBObject(); field.put("HomeTown", 1); DBCursor cursor = db.getCollection(collectionName).find(query,field); while (cursor.hasNext()) { BasicDBObject obj = (BasicDBObject) cursor.next(); result.add(obj.getString("HomeTown")); }更多推荐
如何通过密钥名称从mongoDB中检索值?
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