Shulou(Shulou.com)06/01 Report--

Querying embedded documents is exactly the same as querying ordinary documents.

For example:

> db.post.find () {"_ id": ObjectId ("54ace1394ba07ed75df68f90"), "name": {"firstname": "joe", "lastname": "schome"}, "age": 28} {"_ id": ObjectId ("54ace14a4ba07ed75df68f91"), "name": {"firstname": "snail", "lastname": "yu"} "age": 29} {"_ id": ObjectId ("54ace18d4ba07ed75df68f92"), "name": {"firstname": "sunny", "lastname": "wu"}, "age": 26} > db.post.find ({"name": {"firstname": "joe", "lastname": "schome"}) {"_ id": ObjectId ("54ace1394ba07ed75df68f90"), "name": {"firstname": "joe" "lastname": "schome"}, "age": 28} >

Query embedded documents must match exactly, and cannot be queried if the order is wrong.

We can change it to "." To query embedded documents, so that there is no need for exact matching and no order

For example:

> db.post.find ({"name.firstname": "joe"}) {"_ id": ObjectId ("54ace1394ba07ed75df68f90"), "name": {"firstname": "joe", "lastname": "schome"}, "age": 28} >

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