CODEWITHSUNDEEP
mongodbaggregation-frameworknosql
Nick
Nick

Reputation: 19664

MongoDB - Is it possible to use $or with $cond?

I am trying to aggregate a field based on a date range. I can't figure out how to create a $cond expression that will evaluate more than one expression. I am trying to use the logical $or operator but with no luck.

db.project.aggregate(
    { $match : { brand : 4 } },
    { $project : {
        _id : 0,
        brand : 1,
        count : 1,
        day : 1}
    },  
     { $group : {
        _id : "$brand",
        TotalCount : { $sum : "$count" },        
        TimeRangeCount : {$sum: { $cond: [ { $gte: [ "$day", new Date(2014, 0, 6) ], {$or: [$lte: [ "$day", new Date(2014, 0, 8) ]]} }, "$count", 0 ] }}

    }}    
    )

Is it possible to nest $or within $cond?

Thanks!

Upvotes: 5

Views: 11148

Answers (2)

volodymyrbiryuk
volodymyrbiryuk

Reputation: 29

To answer your original question, yes you can use $or within a $cond.

However, in your case this would be semantically incorrect as you are looking for a range between dates.

For future reference you could use something like this, if for example you wanted to map multiple values to a single value. This is basically saying "if you encounter val1 or val2 or val3 in someField change them to val4.

db.someCollection.aggregate([
{
    someField: {
        $cond: [
            {$or: [
            {$eq: ['$someField', 'val1']},
            {$eq: ['$someField', 'val2']},
            {$eq: ['$someField', 'val3']}
        ]
    },
    'val4',
    '$someField'
  ]}
}]

Upvotes: 2

Nick
Nick

Reputation: 19664

I believe I got it using $and

db.project.aggregate(
    { $match : { brand : 4 } },
    { 
        $project : {
            _id : 0,
            brand : 1,
            count : 1,
            day : 1
        }
    },  
    { 
        $group : {
            _id : "$brand",
            TotalCount : { $sum : "$count" },        
            TimeRangeCount : {
                $sum: { 
                    $cond: [
                        {$and: [
                            {$gte: ["dDay", new Date(2014, 0, 6)]},
                            {$lte: ["$day", new Date(2014, 0, 8)]}
                        ]}, 
                        "$count", 
                        0
                    ]
                }
            }
        }    
    }
)

Upvotes: 9

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