Mongo 数据库查询 | 加入| 在两个集合上创建查询

Question

Select leadId count on two collection in Mongo DB

Collection 1: leads

{
 leadId:"abc123",
 status:"OPENED",
 stage:"start",
 crossSell:
    {
      cc:
         {
            consent:true,
            shown:[{first:true}]
         }
    }
 }

Collection 2: pdata

{
 activeLeadId:"abc123",
 status:"OPENED",
 details:
    [
        {
            rating:10
        },
        {
            rating:9
        }
    ]
}

Question: Find leadId count from leads collection join with pdata collection based on below conditions

1. leads.leadId = pdata.activeleadId and
2. leads.status = "OPENED" and
3. leads.crossSell.cc.consent = true and
4. leads.crossSell.cc.shown[0].first = true and
5. pdata.details.rating >= 5

Answer 1

You can try a aggregation query,

• $match your conditions for leads collection
• $lookup with pdata collection, pass leadId to match with pdata
• match required conditions for pdata
• $limit to return single document, because we don't need that data in response
• $match condition to check is pdata is not empty
• $count to get total number of records

db.leads.aggregate([
  {
    $match: {
      status: "OPENED",
      "crossSell.cc.consent": true,
      "crossSell.cc.shown.first": true
    }
  },
  {
    "$lookup": {
      "from": "pdata",
      "let": { "leadId": "$leadId" },
      "pipeline": [
        {
          $match: {
            $expr: { $eq: ["$$leadId", "$activeLeadId"] },
            "details.rating": { $gte: 5 }
          }
        },
        { $limit: 1 }
      ],
      "as": "pdata"
    }
  },
  { $match: { pdata: { $ne: [] } } },
  { $count: "count" }
])

Playground