there is way to multi group in mongodb ? document i have and want to query it
[ { _id: '1615658138236', englishName: 'samsung smart tv 50', screen_resulation: '4K', screen_size: '50' }, { _id: '1615750981674', englishName: 'lg tv 55 led uhd', screen_resulation: 'UHD', screen_size: '55' }, { _id: '1615791834538', englishName: 'samsung smart 55 inch crystal 4k', screen_resulation: '4K', screen_size: '55' } ]
for example i have 2 unknown fields i use this method to get them
for (let i = 0; i < result[0].filters.length; i++) {
const item = result[0].filters[i].key;
groupBy[item] = `$${item}`;
}
and i try to query mongodb to get count of every field
const products = await Product.aggregate([
{
$match: {
category,
},
},
{
$group: {
_id: groupBy,
count: {
$sum: 1,
},
},
},
{
$sort: { count: -1 },
},
]);
result i get
[
{ _id: { screen_size: '50', screen_resulation: '4K' }, count: 1 },
{ _id: { screen_size: '55', screen_resulation: 'UHD' }, count: 1 },
{ _id: { screen_size: '55', screen_resulation: '4K' }, count: 1 }
]
what i expect is :
[
{ _id: { screen_size: '50' }, count: 1 },
{ _id: { screen_size: '55' }, count: 2 },
{ _id: { screen_resulation: '4K' }, count: 2 },
{ _id: { screen_resulation: 'UHD' }, count: 1 },
]
i really find mongodb is great but very hard for me i dont know why
You can use $facet for multiple aggregation pipelines.
db.collection.aggregate([
{
"$facet": {
"screen_size_count": [
{
"$group": {
"_id": "$screen_size",
"count": {
$sum: 1
}
}
}
],
"screen_resulation_count:": [
{
"$group": {
"_id": "$screen_resulation",
"count": {
$sum: 1
}
}
}
]
}
}
])
Mongo Playground: https://mongoplayground.net/p/cnEY8NV4HNs