aggregation framework - MongoDB Sorting by relevance by matching sub documents -

i have document must searched according value in subdocument , sorted relevancy.

while researching topic, came across question. know have use aggregation framework, solution didn't cover subdocuments.

for example purposes wanted grab every document had sub documents teams.name ['blue', 'red', 'green'] , sorted based on matches had.

league collection: {    coach: henderson,   teams:   [      {        name: red,        logo: bird,        division: east     },     {        name: blue,        logo: bluejay,        division: west     },    {        name: green,        logo: monkey,        division: east     }  ] }  {    coach: wilkins,   teams:   [      {        name: red,        logo: bird,        division: east     },     {        name: blue,        logo: bluejay,        division: west     },  ] }  {    coach: sandy,   teams:   [      {        name: red,        logo: bird,        division: east     }  ] } 

the end result be:

item          total matches --------      -------------- henderson     3 wilkins       2 sandy         1 

how achieve this?

you can try following:

db.league.aggregate(   {$match:{'teams.name':{$in:['red','blue','green']}}},   {$unwind:'$teams'},   {$match:{'teams.name':{$in:['red','blue','green']}}},   {$project:{'item':'$coach','teams':1}},   {$group:{_id:'$item',total:{$sum:1}}},   {$sort:{total:-1}} ) 

the first match match documents team subdocuments matching @ least 1 of red, blue , green. second match remove spurious subdocuments included in first match.