How to query nested objects?

mongodb syntax nested mongodb-query bson
Edmondo1984 picture Edmondo1984 · Apr 14, 2013 · Viewed 182k times · Source

I have a problem when querying mongoDB with nested objects notation:

db.messages.find( { headers : { From: "[email protected]" } } ).count()
0
db.messages.find( { 'headers.From': "[email protected]" }  ).count()
5

I can't see what I am doing wrong. I am expecting nested object notation to return the same result as the dot notation query. Where am I wrong?

Answer

shx2 picture shx2 · Apr 14, 2013

db.messages.find( { headers : { From: "[email protected]" } } )

This queries for documents where headers equals { From: ... }, i.e. contains no other fields.

db.messages.find( { 'headers.From': "[email protected]" } )

This only looks at the headers.From field, not affected by other fields contained in, or missing from, headers.

Dot-notation docs

Related questions

Groovy could not find matching constructor?

Please note: although this question mentions Mongo it is surely a pure Groovy question at heart. My MyApp#bootstrap method: def bootstrap(AppConfiguration config) { String h = config.dbHost String p = config.dbPort println "Mongo is at: ${h}:${p}." dao = new …

Read More
How to query MongoDB with "like"?

I want to query something with SQL's like query: SELECT * FROM users WHERE name LIKE '%m%' How to do I achieve the same in MongoDB? I can't find an operator for like in the documentation.

Read More
Find objects between two dates MongoDB

I've been playing around storing tweets inside mongodb, each object looks like this: { "_id" : ObjectId("4c02c58de500fe1be1000005"), "contributors" : null, "text" : "Hello world", "user" : { "following" : null, "followers_count" : 5, "utc_offset" : null, "location" : "", "profile_text_color" : "000000", "friends_count" : 11, "profile_…

Read More