CODEWITHSUNDEEP
javamongodb
user405398
user405398

Reputation:

How to retrieve a value from mongoDB, by its key name?

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"}}]

In a collection all doc's have different HomeTown, i just know the key name HomeTown, how can i get the HomeTown values?

In mongo site, i just can find find() and findOne().

Thanks!

Upvotes: 21

Views: 85585

Answers (4)

user27
user27

Reputation: 146

for(int value=0;value<=10;value++)
{
 DBCollection tableDetails = db.getCollection("Collection Name");
 BasicDBObject queryDetails = new BasicDBObject();
 queryDetails.put("_id", value);
 DBCursor cursorDetails =tableDetails.find(queryDetails);
 DBObject oneDetails;
 boolean Name=cursorDetails.hasNext();
 while(Name)
  { 
    oneDetails=cursorDetails.next();        
    String data=oneDetails.get("HomeTown").toString();
    System.out.println(data);
  }
}

Upvotes: 1

Dhruv
Dhruv

Reputation: 245

 db.CollectionName.find({},{HomeTown:1,PhoneNumber:0})

Would be wrong, but

 db.CollectionName.find({},{HomeTown:1, _id:0})

would be right, because you need to suppress _id explicitly. Just FYI.

Upvotes: 13

Hitesh Kumar
Hitesh Kumar

Reputation: 31

Mongo m = new Mongo('localhost',27017);
DB db = m.getDB("yourDBName");
Collection coll = db.getCollection("yourCollectionName")
BasicDBObject query = new BasicDBObject();
query.put("HomeTown", 1);
DBCursor cursor = coll.find(query);
ArrayList arr = new ArrayList();
String str;
while (cursor.hasNext()) {
    str=cursor.curr().get("HomeTown").toString();
    arr.add(str);
}

Upvotes: 3

Ron
Ron

Reputation: 364

find() is enough.

db.CollectionName.find({},{HomeTown:1})

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"));
}

Upvotes: 34

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