How to do find in node and mongodb?

Question

This is my \'usergroups\' data

{
    \"_id\": {
        \"$oid\": \"58f7537ec422895572e988a1\"
    },
    \"name\": \"aaa\",
    \"groupname\": \"group north,gro         


        

Answer 1

You can use the below aggregation for 3.4 version.

The query will $match documents in the usergroups collection with the mobilenumber followed by $split to split the groupnames and $lookup the groupname in the groups collection for messages. Final step is to $unwind the mobile_group array to $project the messages for each groupname.

db.usergroups.aggregate([
    { $match: { mobilenumber:"0509867865" } },
    { $project: { groupname:{ $split: [ "$groupname", ',' ] }  } },
    { $lookup:
        {
          from: "groups",
          localField: "groupname",
          foreignField: "groupname",
          as: "mobile_group"
        }
   },
   {$unwind:"$mobile_group"},
   { $project : { groupname:"$mobile_group.groupname", "messages" : "$mobile_group.message" } }
])