How to fetch only the documents that have 3 different values in mongodb?
up vote
0
down vote
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I have the following data in mongodb:
{
"_id" : ObjectId("111"),
"id" : "111",
"classification" : [
{
"annotator" : "annotatorName1",
"category" : "white"
},
{
"annotator" : "annotatorName2",
"category" : "white"
},
{
"annotator" : "annotatorName3",
"category" : "black"
}
]
}
{
"_id" : ObjectId("222"),
"id" : "222",
"classification" : [
{
"annotator" : "annotatorName1",
"category" : "white"
},
{
"annotator" : "annotatorName2",
"category" : "blue"
},
{
"annotator" : "annotatorName3",
"category" : "black"
}
]
}
{
"_id" : ObjectId("333"),
"kind" : "youtube#video",
"etag" : "tagvalue",
"id" : "333"
}
Please note that the classification label does not exists in all my records, as shown in record with id: "333".
I need to get all the records from my database that have different category values.
So, I need a query that when I run it, I will only get the record that has the classification label, and has exactly 3 different category values, in this case, I want a query that will only return this to me:
{
"_id" : ObjectId("222"),
"id" : "222",
"classification" : [
{
"annotator" : "annotatorName1",
"category" : "white"
},
{
"annotator" : "annotatorName2",
"category" : "blue"
},
{
"annotator" : "annotatorName3",
"category" : "black"
}
]
}
What command should I enter in my terminal in order to get all the records that have 3 unique category values under classification, IFF classification exists?
Thank you for your help.
mongodb mongodb-query
asked Nov 8 at 2:25
circuito
31
add a comment |
up vote
0
down vote
favorite
I have the following data in mongodb:
{
"_id" : ObjectId("111"),
"id" : "111",
"classification" : [
{
"annotator" : "annotatorName1",
"category" : "white"
},
{
"annotator" : "annotatorName2",
"category" : "white"
},
{
"annotator" : "annotatorName3",
"category" : "black"
}
]
}
{
"_id" : ObjectId("222"),
"id" : "222",
"classification" : [
{
"annotator" : "annotatorName1",
"category" : "white"
},
{
"annotator" : "annotatorName2",
"category" : "blue"
},
{
"annotator" : "annotatorName3",
"category" : "black"
}
]
}
{
"_id" : ObjectId("333"),
"kind" : "youtube#video",
"etag" : "tagvalue",
"id" : "333"
}
Please note that the classification label does not exists in all my records, as shown in record with id: "333".
I need to get all the records from my database that have different category values.
So, I need a query that when I run it, I will only get the record that has the classification label, and has exactly 3 different category values, in this case, I want a query that will only return this to me:
{
"_id" : ObjectId("222"),
"id" : "222",
"classification" : [
{
"annotator" : "annotatorName1",
"category" : "white"
},
{
"annotator" : "annotatorName2",
"category" : "blue"
},
{
"annotator" : "annotatorName3",
"category" : "black"
}
]
}
What command should I enter in my terminal in order to get all the records that have 3 unique category values under classification, IFF classification exists?
Thank you for your help.
mongodb mongodb-query
asked Nov 8 at 2:25
circuito
31
add a comment |
up vote
0
down vote
favorite
up vote
0
down vote
favorite
I have the following data in mongodb:
{
"_id" : ObjectId("111"),
"id" : "111",
"classification" : [
{
"annotator" : "annotatorName1",
"category" : "white"
},
{
"annotator" : "annotatorName2",
"category" : "white"
},
{
"annotator" : "annotatorName3",
"category" : "black"
}
]
}
{
"_id" : ObjectId("222"),
"id" : "222",
"classification" : [
{
"annotator" : "annotatorName1",
"category" : "white"
},
{
"annotator" : "annotatorName2",
"category" : "blue"
},
{
"annotator" : "annotatorName3",
"category" : "black"
}
]
}
{
"_id" : ObjectId("333"),
"kind" : "youtube#video",
"etag" : "tagvalue",
"id" : "333"
}
Please note that the classification label does not exists in all my records, as shown in record with id: "333".
I need to get all the records from my database that have different category values.
So, I need a query that when I run it, I will only get the record that has the classification label, and has exactly 3 different category values, in this case, I want a query that will only return this to me:
{
"_id" : ObjectId("222"),
"id" : "222",
"classification" : [
{
"annotator" : "annotatorName1",
"category" : "white"
},
{
"annotator" : "annotatorName2",
"category" : "blue"
},
{
"annotator" : "annotatorName3",
"category" : "black"
}
]
}
What command should I enter in my terminal in order to get all the records that have 3 unique category values under classification, IFF classification exists?
Thank you for your help.
mongodb mongodb-query
asked Nov 8 at 2:25
circuito
31
I have the following data in mongodb:
{
"_id" : ObjectId("111"),
"id" : "111",
"classification" : [
{
"annotator" : "annotatorName1",
"category" : "white"
},
{
"annotator" : "annotatorName2",
"category" : "white"
},
{
"annotator" : "annotatorName3",
"category" : "black"
}
]
}
{
"_id" : ObjectId("222"),
"id" : "222",
"classification" : [
{
"annotator" : "annotatorName1",
"category" : "white"
},
{
"annotator" : "annotatorName2",
"category" : "blue"
},
{
"annotator" : "annotatorName3",
"category" : "black"
}
]
}
{
"_id" : ObjectId("333"),
"kind" : "youtube#video",
"etag" : "tagvalue",
"id" : "333"
}
Please note that the classification label does not exists in all my records, as shown in record with id: "333".
I need to get all the records from my database that have different category values.
So, I need a query that when I run it, I will only get the record that has the classification label, and has exactly 3 different category values, in this case, I want a query that will only return this to me:
{
"_id" : ObjectId("222"),
"id" : "222",
"classification" : [
{
"annotator" : "annotatorName1",
"category" : "white"
},
{
"annotator" : "annotatorName2",
"category" : "blue"
},
{
"annotator" : "annotatorName3",
"category" : "black"
}
]
}
What command should I enter in my terminal in order to get all the records that have 3 unique category values under classification, IFF classification exists?
Thank you for your help.
mongodb mongodb-query
mongodb mongodb-query
asked Nov 8 at 2:25
circuito
31
asked Nov 8 at 2:25
circuito
31
asked Nov 8 at 2:25
circuito
31
asked Nov 8 at 2:25
circuito
31
asked Nov 8 at 2:25
circuito
31
31
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
up vote
0
down vote
accepted
The below aggregate can be used to find out the "id"s which have exactly 3 unique categories:
db.collectionName.aggregate([
{$match : {classification : {$exists : true}}},
{$unwind: "$classification"},
{$group: { _id: "$id", uniqueCategories: {$addToSet: "$classification.category"}}},
{$project: {_id : 1, numberOfCategories: {$size: "$uniqueCategories"}} },
{$match: {numberOfCategories: 3} }
])
Explanation: We start with matching documents which have the classification element. Then we $unwind it so as to deconstruct the embedded array into separate documents. Then it is grouped by id, and using $addToSet the categories are collected into an array - this takes care of eliminating any dupes. Then we project its $size and match on 'equal to 3'.
This aggregate will yield documents with the _id set to the id field of the documents in your collection that have 3 unique categories, which you can use to get to the documents. If your collection size is quite large, you should consider adding another $match stage in the beginning to restrict the dataset. As it stands now, it will be doing a collection scan.
answered Nov 8 at 3:23
Bajal
1,98411018
WOW! This actually worked! Thank you!
– circuito
Nov 8 at 17:58
But Bajal, it always fetches only 50.. I know there are more than 50. I want it to retrieve all of them with different classification categories. Why is it only fetching 50?
– circuito
Nov 8 at 18:22
I am guessing you are using robo-3t? It is a limitation of that tool: See: github.com/Studio3T/robomongo/issues/1157 You can run this on the shell and iterate. Or if you execute from any code you will get full results. Don't forget to accept/upvote if this helped :)
– Bajal
Nov 8 at 19:10
I accepted it but it won't let me upvote since I don't have much reputation. Thank you very much for your answer. This solved my problem! :)
– circuito
Nov 10 at 0:33
add a comment |
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
0
down vote
accepted
The below aggregate can be used to find out the "id"s which have exactly 3 unique categories:
db.collectionName.aggregate([
{$match : {classification : {$exists : true}}},
{$unwind: "$classification"},
{$group: { _id: "$id", uniqueCategories: {$addToSet: "$classification.category"}}},
{$project: {_id : 1, numberOfCategories: {$size: "$uniqueCategories"}} },
{$match: {numberOfCategories: 3} }
])
Explanation: We start with matching documents which have the classification element. Then we $unwind it so as to deconstruct the embedded array into separate documents. Then it is grouped by id, and using $addToSet the categories are collected into an array - this takes care of eliminating any dupes. Then we project its $size and match on 'equal to 3'.
This aggregate will yield documents with the _id set to the id field of the documents in your collection that have 3 unique categories, which you can use to get to the documents. If your collection size is quite large, you should consider adding another $match stage in the beginning to restrict the dataset. As it stands now, it will be doing a collection scan.
answered Nov 8 at 3:23
Bajal
1,98411018
WOW! This actually worked! Thank you!
– circuito
Nov 8 at 17:58
But Bajal, it always fetches only 50.. I know there are more than 50. I want it to retrieve all of them with different classification categories. Why is it only fetching 50?
– circuito
Nov 8 at 18:22
I am guessing you are using robo-3t? It is a limitation of that tool: See: github.com/Studio3T/robomongo/issues/1157 You can run this on the shell and iterate. Or if you execute from any code you will get full results. Don't forget to accept/upvote if this helped :)
– Bajal
Nov 8 at 19:10
I accepted it but it won't let me upvote since I don't have much reputation. Thank you very much for your answer. This solved my problem! :)
– circuito
Nov 10 at 0:33
add a comment |
up vote
0
down vote
accepted
The below aggregate can be used to find out the "id"s which have exactly 3 unique categories:
db.collectionName.aggregate([
{$match : {classification : {$exists : true}}},
{$unwind: "$classification"},
{$group: { _id: "$id", uniqueCategories: {$addToSet: "$classification.category"}}},
{$project: {_id : 1, numberOfCategories: {$size: "$uniqueCategories"}} },
{$match: {numberOfCategories: 3} }
])
Explanation: We start with matching documents which have the classification element. Then we $unwind it so as to deconstruct the embedded array into separate documents. Then it is grouped by id, and using $addToSet the categories are collected into an array - this takes care of eliminating any dupes. Then we project its $size and match on 'equal to 3'.
This aggregate will yield documents with the _id set to the id field of the documents in your collection that have 3 unique categories, which you can use to get to the documents. If your collection size is quite large, you should consider adding another $match stage in the beginning to restrict the dataset. As it stands now, it will be doing a collection scan.
answered Nov 8 at 3:23
Bajal
1,98411018
WOW! This actually worked! Thank you!
– circuito
Nov 8 at 17:58
But Bajal, it always fetches only 50.. I know there are more than 50. I want it to retrieve all of them with different classification categories. Why is it only fetching 50?
– circuito
Nov 8 at 18:22
I am guessing you are using robo-3t? It is a limitation of that tool: See: github.com/Studio3T/robomongo/issues/1157 You can run this on the shell and iterate. Or if you execute from any code you will get full results. Don't forget to accept/upvote if this helped :)
– Bajal
Nov 8 at 19:10
I accepted it but it won't let me upvote since I don't have much reputation. Thank you very much for your answer. This solved my problem! :)
– circuito
Nov 10 at 0:33
add a comment |
up vote
0
down vote
accepted
up vote
0
down vote
accepted
The below aggregate can be used to find out the "id"s which have exactly 3 unique categories:
db.collectionName.aggregate([
{$match : {classification : {$exists : true}}},
{$unwind: "$classification"},
{$group: { _id: "$id", uniqueCategories: {$addToSet: "$classification.category"}}},
{$project: {_id : 1, numberOfCategories: {$size: "$uniqueCategories"}} },
{$match: {numberOfCategories: 3} }
])
Explanation: We start with matching documents which have the classification element. Then we $unwind it so as to deconstruct the embedded array into separate documents. Then it is grouped by id, and using $addToSet the categories are collected into an array - this takes care of eliminating any dupes. Then we project its $size and match on 'equal to 3'.
This aggregate will yield documents with the _id set to the id field of the documents in your collection that have 3 unique categories, which you can use to get to the documents. If your collection size is quite large, you should consider adding another $match stage in the beginning to restrict the dataset. As it stands now, it will be doing a collection scan.
answered Nov 8 at 3:23
Bajal
1,98411018
The below aggregate can be used to find out the "id"s which have exactly 3 unique categories:
db.collectionName.aggregate([
{$match : {classification : {$exists : true}}},
{$unwind: "$classification"},
{$group: { _id: "$id", uniqueCategories: {$addToSet: "$classification.category"}}},
{$project: {_id : 1, numberOfCategories: {$size: "$uniqueCategories"}} },
{$match: {numberOfCategories: 3} }
])
Explanation: We start with matching documents which have the classification element. Then we $unwind it so as to deconstruct the embedded array into separate documents. Then it is grouped by id, and using $addToSet the categories are collected into an array - this takes care of eliminating any dupes. Then we project its $size and match on 'equal to 3'.
This aggregate will yield documents with the _id set to the id field of the documents in your collection that have 3 unique categories, which you can use to get to the documents. If your collection size is quite large, you should consider adding another $match stage in the beginning to restrict the dataset. As it stands now, it will be doing a collection scan.
answered Nov 8 at 3:23
Bajal
1,98411018
answered Nov 8 at 3:23
Bajal
1,98411018
answered Nov 8 at 3:23
Bajal
1,98411018
answered Nov 8 at 3:23
Bajal
1,98411018
1,98411018
WOW! This actually worked! Thank you!
– circuito
Nov 8 at 17:58
But Bajal, it always fetches only 50.. I know there are more than 50. I want it to retrieve all of them with different classification categories. Why is it only fetching 50?
– circuito
Nov 8 at 18:22
I am guessing you are using robo-3t? It is a limitation of that tool: See: github.com/Studio3T/robomongo/issues/1157 You can run this on the shell and iterate. Or if you execute from any code you will get full results. Don't forget to accept/upvote if this helped :)
– Bajal
Nov 8 at 19:10
I accepted it but it won't let me upvote since I don't have much reputation. Thank you very much for your answer. This solved my problem! :)
– circuito
Nov 10 at 0:33
add a comment |
WOW! This actually worked! Thank you!
– circuito
Nov 8 at 17:58
But Bajal, it always fetches only 50.. I know there are more than 50. I want it to retrieve all of them with different classification categories. Why is it only fetching 50?
– circuito
Nov 8 at 18:22
I am guessing you are using robo-3t? It is a limitation of that tool: See: github.com/Studio3T/robomongo/issues/1157 You can run this on the shell and iterate. Or if you execute from any code you will get full results. Don't forget to accept/upvote if this helped :)
– Bajal
Nov 8 at 19:10
I accepted it but it won't let me upvote since I don't have much reputation. Thank you very much for your answer. This solved my problem! :)
– circuito
Nov 10 at 0:33
WOW! This actually worked! Thank you!
– circuito
Nov 8 at 17:58
WOW! This actually worked! Thank you!
– circuito
Nov 8 at 17:58
But Bajal, it always fetches only 50.. I know there are more than 50. I want it to retrieve all of them with different classification categories. Why is it only fetching 50?
– circuito
Nov 8 at 18:22
But Bajal, it always fetches only 50.. I know there are more than 50. I want it to retrieve all of them with different classification categories. Why is it only fetching 50?
– circuito
Nov 8 at 18:22
I am guessing you are using robo-3t? It is a limitation of that tool: See: github.com/Studio3T/robomongo/issues/1157 You can run this on the shell and iterate. Or if you execute from any code you will get full results. Don't forget to accept/upvote if this helped :)
– Bajal
Nov 8 at 19:10
I am guessing you are using robo-3t? It is a limitation of that tool: See: github.com/Studio3T/robomongo/issues/1157 You can run this on the shell and iterate. Or if you execute from any code you will get full results. Don't forget to accept/upvote if this helped :)
– Bajal
Nov 8 at 19:10
I accepted it but it won't let me upvote since I don't have much reputation. Thank you very much for your answer. This solved my problem! :)
– circuito
Nov 10 at 0:33
I accepted it but it won't let me upvote since I don't have much reputation. Thank you very much for your answer. This solved my problem! :)
– circuito
Nov 10 at 0:33
add a comment |
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