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db.collection.aggregate([{"$unwind":"$cat"},{"$group":{"_id":{"categoryCode":"$categoryCode","categoryName":"$categoryName"},"catCount":{"$sum":{"$cond":{"if":{"$eq":["$cat.type","A"]},"then":1,"else":0}}}}},{"$project":{"categoryCode":"$_id.categoryCode","categoryName":"$_id.categoryName","catCount":1,"_id":0}}])