db={"county":[{id:"AL",category_id:"DB",Title:"Alabama",},{id:"AK",category_id:"DB",Title:"Alaska"},{id:"AZ",category_id:"NET",Title:"Arizona"}],"ToDo":[{id:"TD1",County_id:"AL",Title:"Installation",assigned:1,user:"ASED"},{id:"TD2",County_id:"AL",Title:"Documentation",assigned:0,user:""},{id:"TD3",County_id:"AL",Title:"Migration",assigned:1,user:"ILKQ"},{id:"TD4",County_id:"AK",Title:"Documentation",assigned:0,user:""},{id:"TD5",County_id:"AZ",Title:"Testing",assigned:0,user:""},{id:"TD6",County_id:"AZ",Title:"Documentation",assigned:1,user:"JUSJ"}],"Category":[{id:"DB",Title:"Database",Desc:"Database Fixes",},{id:"NET",Title:"Network",Desc:"Network Fixes",}]}

db.Category.aggregate([{$match:{}},{"$lookup":{"from":"county","localField":"id","foreignField":"category_id","as":"county"}},{$project:{Desc:1,county:"$county.id",Title:1,id:1}},{"$lookup":{"from":"ToDo","localField":"county","foreignField":"County_id","as":"tasks"}},{"$project":{"total_assigned":{"$sum":{"$sum":"$tasks.assigned"}},"Desc":1,total_rec:{$size:"$tasks"},category_id:"$id",Title:1,_id:0}},])