Question

我有以下带有文件计数的集合师--30，

类别 - 248

productgroup - 1402

产品 - 60000

例如我给出了以下数据分割

{

    "divisionid": "1",
    "divisioncode": "0",
    "divisionname": "ELECTRONICS/HOME APPLIANCE",
    "divisionpoint": "2"
},
{

    "divisionid": "2",
    "divisioncode": "1",
    "divisionname": "FOODS",
    "divisionpoint": "8"
}

类别集合数据

{

    "categoryid": "1",
    "divisionid": "1",
    "categorycode": "34",
    "categoryname": "AUDIO SYSTEM",
    "categorypoint": "Null"
},
{

    "categoryid": "2",
    "divisionid": "1",
    "categorycode": "348",
    "categoryname": "DVD/VCD",
    "categorypoint": "8"
}

产品组合数据

{

    "productgroupid": "1",
    "divisionid": "1",
    "categoryid": "1",
    "productgroupname": "ADAPTOR",
    "productgroupcode": "6765",
    "productgrouppoint": "7"
},
{

    "productgroupid": "2",
    "divisionid": "1",
    "categoryid": "2",
    "productgroupname": "WALKMAN",
    "productgroupcode": "7659",
    "productgrouppoint": "Null"
}

产品收集数据

{

    "productid": "1",
    "divisionid": "1",
    "categoryid": "1",
    "productgroupid":"1",
    "productname":"UNIVERSAL AC DC ADAPTER-PCS",
    "productcode": "1000054",
    "productpoint": "1"
},
{

    "productid": "2",
    "divisionid": "1",
    "categoryid": "2",
    "productgroupid":"2",
    "productname":"WALKMAN WM#M470-PCS",
    "productcode": "1000089",
    "productpoint": "2"
}

我有4个收藏品，如

师，

类，

productgroup，

产品

这些都是我的数据存储在我的部门收集数据

中

{

"divisionid": "1",
"divisioncode": "0",
"divisionname": "ELECTRONICS/HOME APPLIANCE",
"divisionpoint": "2"

}， {

"divisionid": "2",
"divisioncode": "1",
"divisionname": "FOODS",
"divisionpoint": "8"

} 类别集合数据

{

"categoryid": "1",
"divisionid": "1",
"categorycode": "34",
"categoryname": "AUDIO SYSTEM",
"categorypoint": "Null"

}， {

"categoryid": "2",
"divisionid": "1",
"categorycode": "348",
"categoryname": "DVD/VCD",
"categorypoint": "8"

} 产品组收集数据

{

"productgroupid": "1",
"divisionid": "1",
"categoryid": "1",
"productgroupname": "ADAPTOR",
"productgroupcode": "6765",
"productgrouppoint": "7"

}， {

"productgroupid": "2",
"divisionid": "1",
"categoryid": "2",
"productgroupname": "WALKMAN",
"productgroupcode": "7659",
"productgrouppoint": "Null"

} 产品收集数据

{

"productid": "1",
"divisionid": "1",
"categoryid": "1",
"productgroupid":"1",
"productname":"UNIVERSAL AC DC ADAPTER-PCS",
"productcode": "1000054",
"productpoint": "1"

}， {

"productid": "2",
"divisionid": "1",
"categoryid": "2",
"productgroupid":"2",
"productname":"WALKMAN WM#M470-PCS",
"productcode": "1000089",
"productpoint": "2"

} 我想将这4个系列合并为一个系列。我应该得到这样的总结 productsummary

{


        "productpoint": "1",
        "productname": "UNIVERSAL AC DC ADAPTER-PCS",
        "productcode": "10000054",
        "productid"  :"1"

    "group": {
        "point": "7",
        "name": "ADAPTOR",
        "id"  :"1"
    },
    "category": {
        "point": "0",
        "name": "AUDIO SYSTEM",
        "id"  :"1"
    },
    "division": {
        "point": "2",
        "name": "ELECTRONICS/HOME APPLIANCE",
        "id"  :"1"
    }
},
{


        "productpoint": "2",
        "productname": "WALKMAN WM#M470-PCS",
        "productcode": "1000089",
        "productid"  :"2"

    "group": {
        "point": "7",
        "name": "WALKMAN",
        "id"  :"Null"
    },
    "category": {
        "point": "8",
        "name": "DVD/VCD",
        "id"  :"2"
    },
    "division": {
        "point": "2",
        "name": "ELECTRONICS/HOME APPLIANCE",
        "id"  :"1"
    }
}

我运行此代码

db.products.aggregate([ 
    {$lookup:{from:"productgroups", localField:"productgroupid", foreignField:"productgroupid", as:"group"}},
    {$lookup:{from:"category", localField:"categoryid", foreignField:"categoryid", as:"category"}},
    {$lookup:{from:"divisions", localField:"divisionid", foreignField:"divisionid", as:"division"}},
    {$project: {productpoint:1,productname:1,productcode:1,productid:1,group: { $arrayElemAt: [ "$group", 0 ]},
                category: { $arrayElemAt: [ "$category", 0 ]}, division: { $arrayElemAt: [ "$division", 0 ]} }} 
  ]);

它的工作，但我有60 k产品的时间不工作，并得到这样的错误

并且数据在productpointallocations中以这样的方式存储

{

    "productpoint": "2",
        "productname": "WALKMAN WM#M470-PCS",
        "productcode": "1000089",
        "productid"  :"2"
}

有没有其他方法可以做到这一点，并为此

提供一些其他解决方案

nodejs mongodb中还有其他选项吗？

Answer 1

您应该使用$skip和$limit来避免此错误。为什么会出现此错误？你必须阅读@Alex评论链接。

db.products.aggregate([ 
    {$skip:0},{$limit: 1000},
    {$lookup:{from:"productgroups", localField:"productgroupid", foreignField:"productgroupid", as:"group"}},
    {$lookup:{from:"category", localField:"categoryid", foreignField:"categoryid", as:"category"}},
    {$lookup:{from:"divisions", localField:"divisionid", foreignField:"divisionid", as:"division"}},
    {$project: {productpoint:1,productname:1,productcode:1,productid:1,group: { $arrayElemAt: [ "$group", 0 ]},
                category: { $arrayElemAt: [ "$category", 0 ]}, division: { $arrayElemAt: [ "$division", 0 ]} }} 
  ]);

{$skip:0},{$limit: 1000} //初始，然后下次应跳过：1000，限制：1000，依此类推。您可以从请求或使用循环或实施时获得它。

如何使用$ lookup mongodb或nodejs mongodb将多个集合合并到一个集合中？

1 个答案: