CODEWITHSUNDEEP
mongodb
pankaj007
pankaj007

Reputation: 95

Sort by case in mongodb

I have a domain "Notification"

{
  _id: 1
  is_action: false,
  user:[{
        user_id: 5,
        status: "R"
    },
    {
        user_id: 8,
        status: "U"
    }],
    priority:1    
},
{
  _id: 2
  is_action: true,
  user:[{
        user_id: 5,
        status: "U"
    },
    {
        user_id: 8,
        status: "U"
    }],
    priority:1    
}

My query to find notification where user_id = 5 ------ 

db.notifications.aggregate([
    {$unwind:"$user"},
    {$match:{
        "user.user_id":5,
        is_action: false
    }},
    {$sort:{priority:1}}
])

But I need to sort the above query according to the following condition

if(status == "U"){
    Sort by "priority"
}else{
    Sort by "_id"
}

Upvotes: 2

Views: 286

Answers (1)

Flying Fisher
Flying Fisher

Reputation: 1952

Use $cond to create a new field, e.g.

{ $project: { otherfield: 1, sortField: { $cond: { if: { $eq: [ "$status","U" ] }, then: "$priority", else: "$_id" } } } }

And then sort this field.

P.S. $cond is a new operator in MongoDB version 2.6 and above

Upvotes: 2

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