Find in Double Nested Array MongoDB
I have this Collection in mongodb
{
"_id" : "777",
"someKey" : "someValue",
"someArray" : [
{
"name" : "name1",
"someNestedArray" : [
{
"name" : "value"
},
{
"name" : "delete me"
}
]
}
]
}
I want to find document based on someArray.someNestedArray.name
but i can't find any useful link all search result about update nested array
i am trying this but return nothing
db.mycollection.find({"someArray.$.someNestedArray":{"$elemMatch":{"name":"1"}}})
db.mycollection.find({"someArray.$.someNestedArray.$.name":"1"})
and Some thing else
how can i find by element in double nested array mongodb?
mongodb mongodb-query aggregation-framework
add a comment |
I have this Collection in mongodb
{
"_id" : "777",
"someKey" : "someValue",
"someArray" : [
{
"name" : "name1",
"someNestedArray" : [
{
"name" : "value"
},
{
"name" : "delete me"
}
]
}
]
}
I want to find document based on someArray.someNestedArray.name
but i can't find any useful link all search result about update nested array
i am trying this but return nothing
db.mycollection.find({"someArray.$.someNestedArray":{"$elemMatch":{"name":"1"}}})
db.mycollection.find({"someArray.$.someNestedArray.$.name":"1"})
and Some thing else
how can i find by element in double nested array mongodb?
mongodb mongodb-query aggregation-framework
add a comment |
I have this Collection in mongodb
{
"_id" : "777",
"someKey" : "someValue",
"someArray" : [
{
"name" : "name1",
"someNestedArray" : [
{
"name" : "value"
},
{
"name" : "delete me"
}
]
}
]
}
I want to find document based on someArray.someNestedArray.name
but i can't find any useful link all search result about update nested array
i am trying this but return nothing
db.mycollection.find({"someArray.$.someNestedArray":{"$elemMatch":{"name":"1"}}})
db.mycollection.find({"someArray.$.someNestedArray.$.name":"1"})
and Some thing else
how can i find by element in double nested array mongodb?
mongodb mongodb-query aggregation-framework
I have this Collection in mongodb
{
"_id" : "777",
"someKey" : "someValue",
"someArray" : [
{
"name" : "name1",
"someNestedArray" : [
{
"name" : "value"
},
{
"name" : "delete me"
}
]
}
]
}
I want to find document based on someArray.someNestedArray.name
but i can't find any useful link all search result about update nested array
i am trying this but return nothing
db.mycollection.find({"someArray.$.someNestedArray":{"$elemMatch":{"name":"1"}}})
db.mycollection.find({"someArray.$.someNestedArray.$.name":"1"})
and Some thing else
how can i find by element in double nested array mongodb?
mongodb mongodb-query aggregation-framework
mongodb mongodb-query aggregation-framework
edited Jun 30 '17 at 9:15
Neil Lunn
98.1k23174184
98.1k23174184
asked Mar 16 '15 at 7:39
user298582user298582
3641414
3641414
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
In the simplest sense this just follows the basic form of "dot notation" as used by MongoDB. That will work regardless of which array member the inner array member is in, as long as it matches a value:
db.mycollection.find({
"someArray.someNestedArray.name": "value"
})
That is fine for a "single field" value, for matching multiple-fields you would use $elemMatch
:
db.mycollection.find({
"someArray": {
"$elemMatch": {
"name": "name1",
"someNestedArray": {
"$elemMatch": {
"name": "value",
"otherField": 1
}
}
}
}
})
That matches the document which would contain something with a a field at that "path" matching the value. If you intended to "match and filter" the result so only the matched element was returned, this is not possible with the positional operator projection, as quoted:
Nested Arrays
The positional $ operator cannot be used for queries which traverse more than one array, such as queries that traverse arrays nested within other arrays, because the replacement for the $ placeholder is a single value
Modern MongoDB
We can do this by applying $filter
and $map
here. The $map
is really needed because the "inner" array can change as a result of the "filtering", and the "outer" array of course does not match the conditions when the "inner" was stripped of all elements.
Again following the example of actually having multiple properties to match within each array:
db.mycollection.aggregate([
{ "$match": {
"someArray": {
"$elemMatch": {
"name": "name1",
"someNestedArray": {
"$elemMatch": {
"name": "value",
"otherField": 1
}
}
}
}
}},
{ "$addFields": {
"someArray": {
"$filter": {
"input": {
"$map": {
"input": "$someArray",
"as": "sa",
"in": {
"name": "$$sa.name",
"someNestedArray": {
"$filter": {
"input": "$$sa.someNestedArray",
"as": "sn",
"cond": {
"$and": [
{ "$eq": [ "$$sn.name", "value" ] },
{ "$eq": [ "$$sn.otherField", 1 ] }
]
}
}
}
}
},
},
"as": "sa",
"cond": {
"$and": [
{ "$eq": [ "$$sa.name", "name1" ] },
{ "$gt": [ { "$size": "$$sa.someNestedArray" }, 0 ] }
]
}
}
}
}}
])
Therefore on the "outer" array the $filter
actually looks at the $size
of the "inner" array after it was "filtered" itself, so you can reject those results when the whole inner array does in fact match noting.
Older MongoDB
In order to "project" only the matched element, you need the .aggregate()
method:
db.mycollection.aggregate([
// Match possible documents
{ "$match": {
"someArray.someNestedArray.name": "value"
}},
// Unwind each array
{ "$unwind": "$someArray" },
{ "$unwind": "$someArray.someNestedArray" },
// Filter just the matching elements
{ "$match": {
"someArray.someNestedArray.name": "value"
}},
// Group to inner array
{ "$group": {
"_id": {
"_id": "$_id",
"name": "$someArray.name"
},
"someKey": { "$first": "$someKey" },
"someNestedArray": { "$push": "$someArray.someNestedArray" }
}},
// Group to outer array
{ "$group": {
"_id": "$_id._id",
"someKey": { "$first": "$someKey" },
"someArray": { "$push": {
"name": "$_id.name",
"someNestedArray": "$someNestedArray"
}}
}}
])
That allows you to "filter" the matches in nested arrays for one or more results within the document.
Thanks, That is fine for a "single field" value, for matching multiple-fields you would use$elemMatch
this line clarified me the exact use ofelemMatch
,
– Sravan
Oct 10 '17 at 11:26
add a comment |
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1 Answer
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1 Answer
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oldest
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oldest
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oldest
votes
In the simplest sense this just follows the basic form of "dot notation" as used by MongoDB. That will work regardless of which array member the inner array member is in, as long as it matches a value:
db.mycollection.find({
"someArray.someNestedArray.name": "value"
})
That is fine for a "single field" value, for matching multiple-fields you would use $elemMatch
:
db.mycollection.find({
"someArray": {
"$elemMatch": {
"name": "name1",
"someNestedArray": {
"$elemMatch": {
"name": "value",
"otherField": 1
}
}
}
}
})
That matches the document which would contain something with a a field at that "path" matching the value. If you intended to "match and filter" the result so only the matched element was returned, this is not possible with the positional operator projection, as quoted:
Nested Arrays
The positional $ operator cannot be used for queries which traverse more than one array, such as queries that traverse arrays nested within other arrays, because the replacement for the $ placeholder is a single value
Modern MongoDB
We can do this by applying $filter
and $map
here. The $map
is really needed because the "inner" array can change as a result of the "filtering", and the "outer" array of course does not match the conditions when the "inner" was stripped of all elements.
Again following the example of actually having multiple properties to match within each array:
db.mycollection.aggregate([
{ "$match": {
"someArray": {
"$elemMatch": {
"name": "name1",
"someNestedArray": {
"$elemMatch": {
"name": "value",
"otherField": 1
}
}
}
}
}},
{ "$addFields": {
"someArray": {
"$filter": {
"input": {
"$map": {
"input": "$someArray",
"as": "sa",
"in": {
"name": "$$sa.name",
"someNestedArray": {
"$filter": {
"input": "$$sa.someNestedArray",
"as": "sn",
"cond": {
"$and": [
{ "$eq": [ "$$sn.name", "value" ] },
{ "$eq": [ "$$sn.otherField", 1 ] }
]
}
}
}
}
},
},
"as": "sa",
"cond": {
"$and": [
{ "$eq": [ "$$sa.name", "name1" ] },
{ "$gt": [ { "$size": "$$sa.someNestedArray" }, 0 ] }
]
}
}
}
}}
])
Therefore on the "outer" array the $filter
actually looks at the $size
of the "inner" array after it was "filtered" itself, so you can reject those results when the whole inner array does in fact match noting.
Older MongoDB
In order to "project" only the matched element, you need the .aggregate()
method:
db.mycollection.aggregate([
// Match possible documents
{ "$match": {
"someArray.someNestedArray.name": "value"
}},
// Unwind each array
{ "$unwind": "$someArray" },
{ "$unwind": "$someArray.someNestedArray" },
// Filter just the matching elements
{ "$match": {
"someArray.someNestedArray.name": "value"
}},
// Group to inner array
{ "$group": {
"_id": {
"_id": "$_id",
"name": "$someArray.name"
},
"someKey": { "$first": "$someKey" },
"someNestedArray": { "$push": "$someArray.someNestedArray" }
}},
// Group to outer array
{ "$group": {
"_id": "$_id._id",
"someKey": { "$first": "$someKey" },
"someArray": { "$push": {
"name": "$_id.name",
"someNestedArray": "$someNestedArray"
}}
}}
])
That allows you to "filter" the matches in nested arrays for one or more results within the document.
Thanks, That is fine for a "single field" value, for matching multiple-fields you would use$elemMatch
this line clarified me the exact use ofelemMatch
,
– Sravan
Oct 10 '17 at 11:26
add a comment |
In the simplest sense this just follows the basic form of "dot notation" as used by MongoDB. That will work regardless of which array member the inner array member is in, as long as it matches a value:
db.mycollection.find({
"someArray.someNestedArray.name": "value"
})
That is fine for a "single field" value, for matching multiple-fields you would use $elemMatch
:
db.mycollection.find({
"someArray": {
"$elemMatch": {
"name": "name1",
"someNestedArray": {
"$elemMatch": {
"name": "value",
"otherField": 1
}
}
}
}
})
That matches the document which would contain something with a a field at that "path" matching the value. If you intended to "match and filter" the result so only the matched element was returned, this is not possible with the positional operator projection, as quoted:
Nested Arrays
The positional $ operator cannot be used for queries which traverse more than one array, such as queries that traverse arrays nested within other arrays, because the replacement for the $ placeholder is a single value
Modern MongoDB
We can do this by applying $filter
and $map
here. The $map
is really needed because the "inner" array can change as a result of the "filtering", and the "outer" array of course does not match the conditions when the "inner" was stripped of all elements.
Again following the example of actually having multiple properties to match within each array:
db.mycollection.aggregate([
{ "$match": {
"someArray": {
"$elemMatch": {
"name": "name1",
"someNestedArray": {
"$elemMatch": {
"name": "value",
"otherField": 1
}
}
}
}
}},
{ "$addFields": {
"someArray": {
"$filter": {
"input": {
"$map": {
"input": "$someArray",
"as": "sa",
"in": {
"name": "$$sa.name",
"someNestedArray": {
"$filter": {
"input": "$$sa.someNestedArray",
"as": "sn",
"cond": {
"$and": [
{ "$eq": [ "$$sn.name", "value" ] },
{ "$eq": [ "$$sn.otherField", 1 ] }
]
}
}
}
}
},
},
"as": "sa",
"cond": {
"$and": [
{ "$eq": [ "$$sa.name", "name1" ] },
{ "$gt": [ { "$size": "$$sa.someNestedArray" }, 0 ] }
]
}
}
}
}}
])
Therefore on the "outer" array the $filter
actually looks at the $size
of the "inner" array after it was "filtered" itself, so you can reject those results when the whole inner array does in fact match noting.
Older MongoDB
In order to "project" only the matched element, you need the .aggregate()
method:
db.mycollection.aggregate([
// Match possible documents
{ "$match": {
"someArray.someNestedArray.name": "value"
}},
// Unwind each array
{ "$unwind": "$someArray" },
{ "$unwind": "$someArray.someNestedArray" },
// Filter just the matching elements
{ "$match": {
"someArray.someNestedArray.name": "value"
}},
// Group to inner array
{ "$group": {
"_id": {
"_id": "$_id",
"name": "$someArray.name"
},
"someKey": { "$first": "$someKey" },
"someNestedArray": { "$push": "$someArray.someNestedArray" }
}},
// Group to outer array
{ "$group": {
"_id": "$_id._id",
"someKey": { "$first": "$someKey" },
"someArray": { "$push": {
"name": "$_id.name",
"someNestedArray": "$someNestedArray"
}}
}}
])
That allows you to "filter" the matches in nested arrays for one or more results within the document.
Thanks, That is fine for a "single field" value, for matching multiple-fields you would use$elemMatch
this line clarified me the exact use ofelemMatch
,
– Sravan
Oct 10 '17 at 11:26
add a comment |
In the simplest sense this just follows the basic form of "dot notation" as used by MongoDB. That will work regardless of which array member the inner array member is in, as long as it matches a value:
db.mycollection.find({
"someArray.someNestedArray.name": "value"
})
That is fine for a "single field" value, for matching multiple-fields you would use $elemMatch
:
db.mycollection.find({
"someArray": {
"$elemMatch": {
"name": "name1",
"someNestedArray": {
"$elemMatch": {
"name": "value",
"otherField": 1
}
}
}
}
})
That matches the document which would contain something with a a field at that "path" matching the value. If you intended to "match and filter" the result so only the matched element was returned, this is not possible with the positional operator projection, as quoted:
Nested Arrays
The positional $ operator cannot be used for queries which traverse more than one array, such as queries that traverse arrays nested within other arrays, because the replacement for the $ placeholder is a single value
Modern MongoDB
We can do this by applying $filter
and $map
here. The $map
is really needed because the "inner" array can change as a result of the "filtering", and the "outer" array of course does not match the conditions when the "inner" was stripped of all elements.
Again following the example of actually having multiple properties to match within each array:
db.mycollection.aggregate([
{ "$match": {
"someArray": {
"$elemMatch": {
"name": "name1",
"someNestedArray": {
"$elemMatch": {
"name": "value",
"otherField": 1
}
}
}
}
}},
{ "$addFields": {
"someArray": {
"$filter": {
"input": {
"$map": {
"input": "$someArray",
"as": "sa",
"in": {
"name": "$$sa.name",
"someNestedArray": {
"$filter": {
"input": "$$sa.someNestedArray",
"as": "sn",
"cond": {
"$and": [
{ "$eq": [ "$$sn.name", "value" ] },
{ "$eq": [ "$$sn.otherField", 1 ] }
]
}
}
}
}
},
},
"as": "sa",
"cond": {
"$and": [
{ "$eq": [ "$$sa.name", "name1" ] },
{ "$gt": [ { "$size": "$$sa.someNestedArray" }, 0 ] }
]
}
}
}
}}
])
Therefore on the "outer" array the $filter
actually looks at the $size
of the "inner" array after it was "filtered" itself, so you can reject those results when the whole inner array does in fact match noting.
Older MongoDB
In order to "project" only the matched element, you need the .aggregate()
method:
db.mycollection.aggregate([
// Match possible documents
{ "$match": {
"someArray.someNestedArray.name": "value"
}},
// Unwind each array
{ "$unwind": "$someArray" },
{ "$unwind": "$someArray.someNestedArray" },
// Filter just the matching elements
{ "$match": {
"someArray.someNestedArray.name": "value"
}},
// Group to inner array
{ "$group": {
"_id": {
"_id": "$_id",
"name": "$someArray.name"
},
"someKey": { "$first": "$someKey" },
"someNestedArray": { "$push": "$someArray.someNestedArray" }
}},
// Group to outer array
{ "$group": {
"_id": "$_id._id",
"someKey": { "$first": "$someKey" },
"someArray": { "$push": {
"name": "$_id.name",
"someNestedArray": "$someNestedArray"
}}
}}
])
That allows you to "filter" the matches in nested arrays for one or more results within the document.
In the simplest sense this just follows the basic form of "dot notation" as used by MongoDB. That will work regardless of which array member the inner array member is in, as long as it matches a value:
db.mycollection.find({
"someArray.someNestedArray.name": "value"
})
That is fine for a "single field" value, for matching multiple-fields you would use $elemMatch
:
db.mycollection.find({
"someArray": {
"$elemMatch": {
"name": "name1",
"someNestedArray": {
"$elemMatch": {
"name": "value",
"otherField": 1
}
}
}
}
})
That matches the document which would contain something with a a field at that "path" matching the value. If you intended to "match and filter" the result so only the matched element was returned, this is not possible with the positional operator projection, as quoted:
Nested Arrays
The positional $ operator cannot be used for queries which traverse more than one array, such as queries that traverse arrays nested within other arrays, because the replacement for the $ placeholder is a single value
Modern MongoDB
We can do this by applying $filter
and $map
here. The $map
is really needed because the "inner" array can change as a result of the "filtering", and the "outer" array of course does not match the conditions when the "inner" was stripped of all elements.
Again following the example of actually having multiple properties to match within each array:
db.mycollection.aggregate([
{ "$match": {
"someArray": {
"$elemMatch": {
"name": "name1",
"someNestedArray": {
"$elemMatch": {
"name": "value",
"otherField": 1
}
}
}
}
}},
{ "$addFields": {
"someArray": {
"$filter": {
"input": {
"$map": {
"input": "$someArray",
"as": "sa",
"in": {
"name": "$$sa.name",
"someNestedArray": {
"$filter": {
"input": "$$sa.someNestedArray",
"as": "sn",
"cond": {
"$and": [
{ "$eq": [ "$$sn.name", "value" ] },
{ "$eq": [ "$$sn.otherField", 1 ] }
]
}
}
}
}
},
},
"as": "sa",
"cond": {
"$and": [
{ "$eq": [ "$$sa.name", "name1" ] },
{ "$gt": [ { "$size": "$$sa.someNestedArray" }, 0 ] }
]
}
}
}
}}
])
Therefore on the "outer" array the $filter
actually looks at the $size
of the "inner" array after it was "filtered" itself, so you can reject those results when the whole inner array does in fact match noting.
Older MongoDB
In order to "project" only the matched element, you need the .aggregate()
method:
db.mycollection.aggregate([
// Match possible documents
{ "$match": {
"someArray.someNestedArray.name": "value"
}},
// Unwind each array
{ "$unwind": "$someArray" },
{ "$unwind": "$someArray.someNestedArray" },
// Filter just the matching elements
{ "$match": {
"someArray.someNestedArray.name": "value"
}},
// Group to inner array
{ "$group": {
"_id": {
"_id": "$_id",
"name": "$someArray.name"
},
"someKey": { "$first": "$someKey" },
"someNestedArray": { "$push": "$someArray.someNestedArray" }
}},
// Group to outer array
{ "$group": {
"_id": "$_id._id",
"someKey": { "$first": "$someKey" },
"someArray": { "$push": {
"name": "$_id.name",
"someNestedArray": "$someNestedArray"
}}
}}
])
That allows you to "filter" the matches in nested arrays for one or more results within the document.
edited Jun 30 '17 at 9:15
answered Mar 16 '15 at 8:03
Neil LunnNeil Lunn
98.1k23174184
98.1k23174184
Thanks, That is fine for a "single field" value, for matching multiple-fields you would use$elemMatch
this line clarified me the exact use ofelemMatch
,
– Sravan
Oct 10 '17 at 11:26
add a comment |
Thanks, That is fine for a "single field" value, for matching multiple-fields you would use$elemMatch
this line clarified me the exact use ofelemMatch
,
– Sravan
Oct 10 '17 at 11:26
Thanks, That is fine for a "single field" value, for matching multiple-fields you would use
$elemMatch
this line clarified me the exact use of elemMatch
,– Sravan
Oct 10 '17 at 11:26
Thanks, That is fine for a "single field" value, for matching multiple-fields you would use
$elemMatch
this line clarified me the exact use of elemMatch
,– Sravan
Oct 10 '17 at 11:26
add a comment |
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