|
{
"beer_name" : "Reveller",
"brewery_name" : "Orchard Pig",
"beer_type" : "Cider"
}
{
"beer_name" : "Hefe Weisse",
"brewery_name" : "Paulaner Gruppe",
"beer_type" : "Hefeweizen"
}
{
"beer_name" : "Münchener Gold",
"brewery_name" : "Paulaner Gruppe",
"beer_type" : "Dortmunder Lager"
}
|
→
|
{ $group: {
* _id: '$brewery_name',*
beers: { *'$addToSet': '$beer_name'* }
} }
↓
{
"_id" : "Paulaner Gruppe",
"beers" : [
"Münchener Gold",
"Hefe Weisse"
]
}
{
"_id" : "Orchard Pig",
"beers" : [
"Reveller"
]
}
|