MongoDb过滤器阵列

Question

数据结构：

[{
"_id": {
"$oid": "5f1e91da1d840d673d159e69"
},
"product": [
{
"_id": "1",
"name": "FirstWarehouseName1",
"image": "FirstWarehousePhoto1",
"manufacturer": "FirstWarehouseProducer1",
"warehouse": "Warehouse1",
"price": "32",
"amount": 344
},
{
"_id": "2",
"name": "FirstWarehouseName2",
"image": "FirstWarehousePhoto2",
"manufacturer": "FirstWarehouseProducer2",
"warehouse": "Warehouse1",
"price": "12",
"amount": 631
},
{
"_id": "3",
"name": "FirstWarehouseName3",
"image": "FirstWarehousePhoto3",
"manufacturer": "FirstWarehouseProducer3",
"warehouse": "Warehouse1",
"price": "66",
"amount": 752
}
],
"_class": "pl.com.ttsw.intership.product_model.Products"
},{
"_id": {
"$oid": "5f1e91da1d840d673d159e6a"
},
"product": [
{
"_id": "1",
"name": "SecondWarehouseName1",
"image": "SecondWarehousePhoto1",
"manufacturer": "SecondWarehouseProducerName1",
"warehouse": "Warehouse2",
"price": "32",
"amount": 344
},
{
"_id": "2",
"name": "SecondWarehouseName2",
"image": "SecondWarehousePhoto2",
"manufacturer": "SecondWarehouseProducerName2",
"warehouse": "Warehouse2",
"price": "12",
"amount": 631
},
{
"_id": "3",
"name": "SecondWarehouseName3",
"image": "SecondWarehousePhoto3",
"manufacturer": "SecondWarehouseProducerName3",
"warehouse": "Warehouse2",
"price": "66",
"amount": 752
}
],
"_class": "pl.com.ttsw.intership.product_model.Products"
},{
"_id": {
"$oid": "5f1e91db1d840d673d159e6b"
},
"product": [
{
"_id": "1",
"name": "ThirdWarehouseName1",
"image": "ThirdWarehousePhoto1",
"manufacturer": "ThirdWarehouse1",
"warehouse": "Warehouse3",
"price": "44",
"amount": 123
},
{
"_id": "2",
"name": "ThirdWarehouseName2",
"image": "ThirdWarehousePhoto2",
"manufacturer": "ThirdWarehouse2",
"warehouse": "Warehouse3",
"price": "11",
"amount": 442
},
{
"_id": "3",
"name": "ThirdWarehouseName3",
"image": "ThirdWarehousePhoto3",
"manufacturer": "ThirdWarehouse3",
"warehouse": "Warehouse3",
"price": "2",
"amount": 2213
}
],
"_class": "pl.com.ttsw.intership.product_model.Products"
}]

IMG

我也这样尝试：

IMG2

错误

///////////////////////////////////////////////////////////////我需要按名称过滤数组中的数组(仓库中的产品(；如果我做的没有项目响应是数组与所有产品。如果(按"Name3"搜索(

[{
"_id": {
"$oid": "5f1e91da1d840d673d159e69"
},
"product": [
{
"_id": "3",
"name": "FirstWarehouseName3",
"image": "FirstWarehousePhoto3",
"manufacturer": "FirstWarehouseProducer3",
"warehouse": "Warehouse1",
"price": "66",
"amount": 752
}
]
},{
"_id": {
"$oid": "5f1e91da1d840d673d159e6a"
},
"product": [
{
"_id": "3",
"name": "SecondWarehouseName3",
"image": "SecondWarehousePhoto3",
"manufacturer": "SecondWarehouseProducerName3",
"warehouse": "Warehouse2",
"price": "66",
"amount": 752
}
]
},{
"_id": {
"$oid": "5f1e91db1d840d673d159e6b"
},
"product": [
{
"_id": "3",
"name": "ThirdWarehouseName3",
"image": "ThirdWarehousePhoto3",
"manufacturer": "ThirdWarehouse3",
"warehouse": "Warehouse3",
"price": "2",
"amount": 2213
}
]
}]

我试了所有的方法，但我都做不到。////////////////////////////////

Answer 1

您可以进行

[{
$unwind: {
path: "$product",
preserveNullAndEmptyArrays: false
}
}, {
$match: {
"product.name": {
$regex: "Name3"
}
}
}, {
$group: {
_id: "$_id",
product: {
$push: "$product"
}
}
}]

工作Mongo游乐场

Answer 2

如果只过滤数组中的一个元素，即使只有一个元素匹配，也会返回整个数组，如果没有匹配，则不会返回任何内容。因此，您需要使用$unwind运算符将数组分隔为不同的文档，然后尝试使用$match筛选结果。

以下查询可能会解决您的问题：

db.collection.aggregate([
{"$unwind": "$product"},
{"$match": {"product.name": "FirstWarehouseName1"}} // replace here with the name you want
])

工作间地面

如果可以的话，只是一个提示：您应该将每个产品存储在不同的文档中，尽管MongoDB是无架构的，并且允许我们拥有几乎任何格式的文档，但请记住，每个文档都应该包含相当于常规关系数据库中一行的信息。否则，您将开始出现这些问题，此外还有性能问题。