用聚合升序对MongoDB文档进行排序？
在MongoDB聚合中使用$sort。让我们创建一个包含文档的集合-
> db.demo652.insertOne({
... value:10,
... "details" : [{
... "ProductName" : "Product-1",
... "ProductQuantity" : 8,
... "ProductPrice" : 500
... }, {
... "ProductName" : "Product-2",
... "ProductQuantity" : 7,
... "ProductPrice" : 500
...
... }]
... }
... );
{
"acknowledged" : true,
"insertedId" : ObjectId("5e9f0730e3c3cd0dcff36a62")
}
>
> db.demo652.insertOne({
... value:5,
... "details" : [{
... "ProductName" : "Product-1",
... "ProductQuantity" : 8,
... "ProductPrice" : 500
... }, {
... "ProductName" : "Product-2",
... "ProductQuantity" : 7,
... "ProductPrice" : 500
...
... }]
... }
... );
{
"acknowledged" : true,
"insertedId" : ObjectId("5e9f0740e3c3cd0dcff36a63")
}在find()方法的帮助下显示集合中的所有文档-
> db.demo652.find();
这将产生以下输出-
{ "_id" : ObjectId("5e9f0730e3c3cd0dcff36a62"), "value" : 10, "details" : [ { "ProductName" : "Product-1", "ProductQuantity" : 8, "ProductPrice" : 500 }, { "ProductName" : "Product-2", "ProductQuantity" : 7, "ProductPrice" : 500 } ] }
{ "_id" : ObjectId("5e9f0740e3c3cd0dcff36a63"), "value" : 5, "details" : [ { "ProductName" : "Product-1", "ProductQuantity" : 8, "ProductPrice" : 500 }, { "ProductName" : "Product-2", "ProductQuantity" : 7, "ProductPrice" : 500 } ] }以下是按升序排序的查询-
> db.demo652.aggregate([{
... "$unwind": "$details"
... }, {
... "$match": {}
... }, {
... "$group": {
... "ProductPrice": {
... "$first": "$value"
... },
... "details": {
... "$push": {
... "ProductName": "$details.ProductName"
... }
... },
... "_id": "$_id"
... }
... }, {
... "$sort": {
... "ProductPrice": 1
... }
... }, {
... "$project": {
... "_id": 0,
... "ProductPrice": 1,
... "details": 1
... }
... }]).pretty()这将产生以下输出-
{
"ProductPrice" : 5,
"details" : [
{
"ProductName" : "Product-1"
},
{
"ProductName" : "Product-2"
}
]
}
{
"ProductPrice" : 10,
"details" : [
{
"ProductName" : "Product-1"
},
{
"ProductName" : "Product-2"
}
]
}