Querying array of Embedded Documents in MongoDB based on Range?

To query an array of embedded documents based on range, use aggregate(). Let us create a collection with documents −

> db.demo346.insertOne( ...    { ...       _id: 101, ...       userDetails: [ ...          { UserName: "Chris", Score:78}, ...          { UserName: "David", Score:68}, ...          { UserName: "Bob", Score:88} ...       ] ...    } ... ); { "acknowledged" : true, "insertedId" : 101 } > db.demo346.insertOne( ...    { ...       _id: 102, ...       userDetails: [ ...          { UserName: "Mike", Score:92}, ...          { UserName: "Sam", Score:62}, ...          { UserName: "Carol", Score:97} ...       ] ...    } ... ); { "acknowledged" : true, "insertedId" : 102 }

Display all documents from a collection with the help of find() method −

> db.demo346.find();

This will produce the following output −

{    "_id" : 101, "userDetails" : [       { "UserName" : "Chris", "Score" : 78 },       { "UserName" : "David", "Score" : 68 },       { "UserName" : "Bob", "Score" : 88 }    ] } {    "_id" : 102, "userDetails" : [       { "UserName" : "Mike", "Score" : 92 },       { "UserName" : "Sam", "Score" : 62 },       { "UserName" : "Carol", "Score" : 97 }    ] }

Following is how to query an array of embedded documents in MongoDB based on Range −

> db.demo346.aggregate([ ...    { "$match": { "$expr": { "$gte": [{ "$size": { "$ifNull": ["$userDetails", []] } }, 1] }}}, ...    { "$addFields": { ...          "userDetails": { ...          "$filter": { ...             "input": { "$ifNull": ["$userDetails", []] }, ...             "cond": { ...                "$and": [ ...                   { "$gte": ["$$this.Score", 80] }, ...                   { "$lte": ["$$this.Score", 99] } ...                ] ...             } ...          } ...       } ...    }} ... ])

This will produce the following output −

{ "_id" : 101, "userDetails" : [ { "UserName" : "Bob", "Score" : 88 } ] } { "_id" : 102, "userDetails" : [ { "UserName" : "Mike", "Score" : 92 }, { "UserName" : "Carol", "Score" : 97 } ] }