Use $match to filter multiple conditions in Aggregation framework

Filter multiple conditions using $match

Situation: At the beginning of an Aggregation pipeline, you may want to filter for multiple conditions before $project.

Here’s how you’d do it. Use $and operator with an array of conditions. This example is from the Bounty Board project. The query is filtering for season, customer_id and status:

db.bounties.aggregate([
    {$match: {"$and": [{season: 2}, {customer_id: '905250069463326740'}, {status: "Completed"}]}},
    {$project: {_id: 0, customer_id: 1, "reward.amount": 1, "reward.currency": 1, status: 1}},
    {$group: {_id: "$customer_id", sum: {$sum: "$reward.amount"}}}
])

Incidentally, this pipeline is a useful pattern to remember: $match -> $project -> $group.

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