database - MongoDb sort array values not working in aggregation pipeline

Question

consider the following collection:

{"productId" : 1,
"isVariant": 1,
"isComplete" : 1,
"variantId" : 1,
"attributeSet" : [ 
        {
            "name" : "Capacity",
            "value" : "500 GB",
            "id" : 3
        }, 
        {
            "name" : "Form Factor",
            "value" : "5 inch",
            "id" : 4
        }, 
        {
            "id" : 5,
            "name" : "Memory Components",
            "value" : "3D NAND",
            "isVariation" : 0
        }
    ]
},
{"productId" : 2,
"isVariant": 1,
"isComplete" : 1,
"variantId" : 1,
"attributeSet" : [ 
        {
            "name" : "Capacity",
            "value" : "1 TB",
            "id" : 3
        }, 
        {
            "name" : "Form Factor",
            "value" : "5 inch",
            "id" : 4
        }, 
        {
            "id" : 5,
            "name" : "Memory Components",
            "value" : "3D NAND",
            "isVariation" : 0
        }
    ]
},
{"productId" : 3,
"isVariant": 1,
"isComplete" : 0,
"variantId" : 1,
"attributeSet" : [ 
        {
            "name" : "Capacity",
            "value" : "500 GB",
            "id" : 3
        }, 
        {
            "name" : "Form Factor",
            "value" : "2.5 inch",
            "id" : 4
        }, 
        {
            "id" : 5,
            "name" : "Memory Components",
            "value" : "3D NAND",
            "isVariation" : 0
        }
    ]
},
{"productId" : 4,
"isVariant": 1,
"isComplete" : 0,
"variantId" : 1,
"attributeSet" : [ 
        {
            "name" : "Capacity",
            "value" : "1 TB",
            "id" : 3
        }, 
        {
            "name" : "Form Factor",
            "value" : "2.5 inch",
            "id" : 4
        }, 
        {
            "id" : 5,
            "name" : "Memory Components",
            "value" : "3D NAND",
            "isVariation" : 0
        }
    ]
}

Here's my query for returning the values of each attribute set values that are not variation.

db.collection.aggregate([
  { $match: { isComplete: 1 } },
  {
    $project: {
      _id: 0,
      attributeSet: 1
    }
  },
  { $unwind: "$attributeSet" },
  { $match: { "attributeSet.isVariation": { $ne: 0 } } },
  {
    $group: {
      _id: "$attributeSet.id",
      name: { $first: "$attributeSet.name"  },
      values: { $addToSet: "$attributeSet.value" }
    }
  },
{ 
 $sort: {
   name : 1,
   values : 1
 }
}
])

The above query works fine and resulting the desired output but the only problem is while sorting the values. The sort stage works fine for name but the values which is an array does not get sorted. Can anyone help me with this query?

Answer 1

等待大神答复