Why do aggregating a filtered dataset lose the filters of it?
0
I have this collection:
// collection
[
{_id: 1, name: 'Luigi', childs: [{name: 'one'}, {name: 'two'}], dad_id: 9]},
{_id: 1, name: 'Mario', childs: [{name: 'four'}, {name: 'five'}], dad_id: 8]},
{_id: 1, name: 'Alessandro', childs: [{name: 'seven'}, {name: 'six'}], dad_id: 9]},
]
and apply this filter to it
result = collection.find({ dad_id: 9 })
Then I want to aggregate the results and get all the childs singularly, I start with unwinding them
(then I 'll make a projection, etc..) but I already encounter a behavior that I do not understand:
the result contains also the documents with dad_id is 8, even if they were already excluded by my query.
result.aggregate([
{ "$unwind"=> "$childs" },
]).each do |e| ... end
// => [
{_id: 1, name: 'Luigi', childs: {name: 'one'}, dad_id: 9]},
{_id: 1, name: 'Luigi', childs: {name: 'two'}, dad_id: 9]},
{_id: 1, name: 'Luigi', childs: {name: 'five'}, dad_id: 8]},
{_id: 1, name: 'Luigi', childs: {name: 'four'}, dad_id: 8]},
{_id: 1, name: 'Luigi', childs: {name: 'seven'}, dad_id: 9]},
{_id: 1, name: 'Luigi', childs: {name: 'six'}, dad_id: 9]},
]
What am I missing?
ruby mongodb
asked Nov 22 '18 at 10:47
ciaobenciaoben
794920
|
show 1 more comment
0
I have this collection:
// collection
[
{_id: 1, name: 'Luigi', childs: [{name: 'one'}, {name: 'two'}], dad_id: 9]},
{_id: 1, name: 'Mario', childs: [{name: 'four'}, {name: 'five'}], dad_id: 8]},
{_id: 1, name: 'Alessandro', childs: [{name: 'seven'}, {name: 'six'}], dad_id: 9]},
]
and apply this filter to it
result = collection.find({ dad_id: 9 })
Then I want to aggregate the results and get all the childs singularly, I start with unwinding them
(then I 'll make a projection, etc..) but I already encounter a behavior that I do not understand:
the result contains also the documents with dad_id is 8, even if they were already excluded by my query.
result.aggregate([
{ "$unwind"=> "$childs" },
]).each do |e| ... end
// => [
{_id: 1, name: 'Luigi', childs: {name: 'one'}, dad_id: 9]},
{_id: 1, name: 'Luigi', childs: {name: 'two'}, dad_id: 9]},
{_id: 1, name: 'Luigi', childs: {name: 'five'}, dad_id: 8]},
{_id: 1, name: 'Luigi', childs: {name: 'four'}, dad_id: 8]},
{_id: 1, name: 'Luigi', childs: {name: 'seven'}, dad_id: 9]},
{_id: 1, name: 'Luigi', childs: {name: 'six'}, dad_id: 9]},
]
What am I missing?
ruby mongodb
asked Nov 22 '18 at 10:47
ciaobenciaoben
794920
Which driver is this? You should not even be able to do that. It's certainly not standard with any other language driver and since it is not working, then this "feature" is not even implemented properly. You're supposed to use a$matchstage in the aggregation pipeline. And MongoDB "views" are something completely different.
– Neil Lunn
Nov 22 '18 at 10:54
Yeah about the view your are right, I am calling them poorly. I will edit the question. The driver any way is ruby. My question remain the same but change the word view with "dataset"
– ciaoben
Nov 22 '18 at 10:56
It's not a matter of what you are calling it, but rather that no officially supported driver has any such feature as you are claiming. So what you need to tell us is "where did you install this driver from?"
– Neil Lunn
Nov 22 '18 at 10:58
@NeilLunn it is the official gem "mongo" version 2.3.0
– ciaoben
Nov 22 '18 at 11:01
Yeah was just looking at it and it's pretty bad that this is exposed this way. As stated, you are not actually meant to even try and use it that way, and no other language driver even allows it. Instead you$matchin the pipeline itselfcollection.aggregate([{ "$match" => { dad_id: 9 } },{ "$unwind"=> "$childs" }]). So the "bugginess" in the driver is thefind()returns a "Collection View" which exposes anaggregate()method which should not actually be there. Do it with theCollectionmethod like everyone else does.
– Neil Lunn
Nov 22 '18 at 11:12
|
show 1 more comment
0
0
0
I have this collection:
// collection
[
{_id: 1, name: 'Luigi', childs: [{name: 'one'}, {name: 'two'}], dad_id: 9]},
{_id: 1, name: 'Mario', childs: [{name: 'four'}, {name: 'five'}], dad_id: 8]},
{_id: 1, name: 'Alessandro', childs: [{name: 'seven'}, {name: 'six'}], dad_id: 9]},
]
and apply this filter to it
result = collection.find({ dad_id: 9 })
Then I want to aggregate the results and get all the childs singularly, I start with unwinding them
(then I 'll make a projection, etc..) but I already encounter a behavior that I do not understand:
the result contains also the documents with dad_id is 8, even if they were already excluded by my query.
result.aggregate([
{ "$unwind"=> "$childs" },
]).each do |e| ... end
// => [
{_id: 1, name: 'Luigi', childs: {name: 'one'}, dad_id: 9]},
{_id: 1, name: 'Luigi', childs: {name: 'two'}, dad_id: 9]},
{_id: 1, name: 'Luigi', childs: {name: 'five'}, dad_id: 8]},
{_id: 1, name: 'Luigi', childs: {name: 'four'}, dad_id: 8]},
{_id: 1, name: 'Luigi', childs: {name: 'seven'}, dad_id: 9]},
{_id: 1, name: 'Luigi', childs: {name: 'six'}, dad_id: 9]},
]
What am I missing?
ruby mongodb
asked Nov 22 '18 at 10:47
ciaobenciaoben
794920
I have this collection:
// collection
[
{_id: 1, name: 'Luigi', childs: [{name: 'one'}, {name: 'two'}], dad_id: 9]},
{_id: 1, name: 'Mario', childs: [{name: 'four'}, {name: 'five'}], dad_id: 8]},
{_id: 1, name: 'Alessandro', childs: [{name: 'seven'}, {name: 'six'}], dad_id: 9]},
]
and apply this filter to it
result = collection.find({ dad_id: 9 })
Then I want to aggregate the results and get all the childs singularly, I start with unwinding them
(then I 'll make a projection, etc..) but I already encounter a behavior that I do not understand:
the result contains also the documents with dad_id is 8, even if they were already excluded by my query.
result.aggregate([
{ "$unwind"=> "$childs" },
]).each do |e| ... end
// => [
{_id: 1, name: 'Luigi', childs: {name: 'one'}, dad_id: 9]},
{_id: 1, name: 'Luigi', childs: {name: 'two'}, dad_id: 9]},
{_id: 1, name: 'Luigi', childs: {name: 'five'}, dad_id: 8]},
{_id: 1, name: 'Luigi', childs: {name: 'four'}, dad_id: 8]},
{_id: 1, name: 'Luigi', childs: {name: 'seven'}, dad_id: 9]},
{_id: 1, name: 'Luigi', childs: {name: 'six'}, dad_id: 9]},
]
What am I missing?
ruby mongodb
ruby mongodb
asked Nov 22 '18 at 10:47
ciaobenciaoben
794920
asked Nov 22 '18 at 10:47
ciaobenciaoben
794920
edited Nov 22 '18 at 10:57
ciaoben
asked Nov 22 '18 at 10:47
ciaobenciaoben
794920
asked Nov 22 '18 at 10:47
ciaobenciaoben
794920
asked Nov 22 '18 at 10:47
ciaobenciaoben
794920
794920
Which driver is this? You should not even be able to do that. It's certainly not standard with any other language driver and since it is not working, then this "feature" is not even implemented properly. You're supposed to use a$matchstage in the aggregation pipeline. And MongoDB "views" are something completely different.
– Neil Lunn
Nov 22 '18 at 10:54
Yeah about the view your are right, I am calling them poorly. I will edit the question. The driver any way is ruby. My question remain the same but change the word view with "dataset"
– ciaoben
Nov 22 '18 at 10:56
It's not a matter of what you are calling it, but rather that no officially supported driver has any such feature as you are claiming. So what you need to tell us is "where did you install this driver from?"
– Neil Lunn
Nov 22 '18 at 10:58
@NeilLunn it is the official gem "mongo" version 2.3.0
– ciaoben
Nov 22 '18 at 11:01
Yeah was just looking at it and it's pretty bad that this is exposed this way. As stated, you are not actually meant to even try and use it that way, and no other language driver even allows it. Instead you$matchin the pipeline itselfcollection.aggregate([{ "$match" => { dad_id: 9 } },{ "$unwind"=> "$childs" }]). So the "bugginess" in the driver is thefind()returns a "Collection View" which exposes anaggregate()method which should not actually be there. Do it with theCollectionmethod like everyone else does.
– Neil Lunn
Nov 22 '18 at 11:12
|
show 1 more comment
Which driver is this? You should not even be able to do that. It's certainly not standard with any other language driver and since it is not working, then this "feature" is not even implemented properly. You're supposed to use a$matchstage in the aggregation pipeline. And MongoDB "views" are something completely different.
– Neil Lunn
Nov 22 '18 at 10:54
Yeah about the view your are right, I am calling them poorly. I will edit the question. The driver any way is ruby. My question remain the same but change the word view with "dataset"
– ciaoben
Nov 22 '18 at 10:56
It's not a matter of what you are calling it, but rather that no officially supported driver has any such feature as you are claiming. So what you need to tell us is "where did you install this driver from?"
– Neil Lunn
Nov 22 '18 at 10:58
@NeilLunn it is the official gem "mongo" version 2.3.0
– ciaoben
Nov 22 '18 at 11:01
Yeah was just looking at it and it's pretty bad that this is exposed this way. As stated, you are not actually meant to even try and use it that way, and no other language driver even allows it. Instead you$matchin the pipeline itselfcollection.aggregate([{ "$match" => { dad_id: 9 } },{ "$unwind"=> "$childs" }]). So the "bugginess" in the driver is thefind()returns a "Collection View" which exposes anaggregate()method which should not actually be there. Do it with theCollectionmethod like everyone else does.
– Neil Lunn
Nov 22 '18 at 11:12
Which driver is this? You should not even be able to do that. It's certainly not standard with any other language driver and since it is not working, then this "feature" is not even implemented properly. You're supposed to use a
$match stage in the aggregation pipeline. And MongoDB "views" are something completely different.– Neil Lunn
Nov 22 '18 at 10:54
Which driver is this? You should not even be able to do that. It's certainly not standard with any other language driver and since it is not working, then this "feature" is not even implemented properly. You're supposed to use a
$match stage in the aggregation pipeline. And MongoDB "views" are something completely different.– Neil Lunn
Nov 22 '18 at 10:54
Yeah about the view your are right, I am calling them poorly. I will edit the question. The driver any way is ruby. My question remain the same but change the word view with "dataset"
– ciaoben
Nov 22 '18 at 10:56
Yeah about the view your are right, I am calling them poorly. I will edit the question. The driver any way is ruby. My question remain the same but change the word view with "dataset"
– ciaoben
Nov 22 '18 at 10:56
It's not a matter of what you are calling it, but rather that no officially supported driver has any such feature as you are claiming. So what you need to tell us is "where did you install this driver from?"
– Neil Lunn
Nov 22 '18 at 10:58
It's not a matter of what you are calling it, but rather that no officially supported driver has any such feature as you are claiming. So what you need to tell us is "where did you install this driver from?"
– Neil Lunn
Nov 22 '18 at 10:58
@NeilLunn it is the official gem "mongo" version 2.3.0
– ciaoben
Nov 22 '18 at 11:01
@NeilLunn it is the official gem "mongo" version 2.3.0
– ciaoben
Nov 22 '18 at 11:01
Yeah was just looking at it and it's pretty bad that this is exposed this way. As stated, you are not actually meant to even try and use it that way, and no other language driver even allows it. Instead you
$match in the pipeline itself collection.aggregate([{ "$match" => { dad_id: 9 } },{ "$unwind"=> "$childs" }]). So the "bugginess" in the driver is the find() returns a "Collection View" which exposes an aggregate() method which should not actually be there. Do it with the Collection method like everyone else does.– Neil Lunn
Nov 22 '18 at 11:12
Yeah was just looking at it and it's pretty bad that this is exposed this way. As stated, you are not actually meant to even try and use it that way, and no other language driver even allows it. Instead you
$match in the pipeline itself collection.aggregate([{ "$match" => { dad_id: 9 } },{ "$unwind"=> "$childs" }]). So the "bugginess" in the driver is the find() returns a "Collection View" which exposes an aggregate() method which should not actually be there. Do it with the Collection method like everyone else does.– Neil Lunn
Nov 22 '18 at 11:12
|
show 1 more comment
1 Answer
1
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You can not chain input from one query to another query like that.
Either use search query ex. Model.find(id) or aggregation framework.
Aggregation framework provides you the functionality to create a pipeline (ex. match,unwind,lookup,project).
To utilize mongodb indexing always try to use "$match" first in the pipeline
match = { "$match" => { "dad_id" =>9} }
unwind = {"$uwind"=>"$childs"}
pipeline = [match,unwind]
collection.aggregate(pipeline).each do |obj|
end
answered Nov 22 '18 at 11:59
Mukul DevMukul Dev
814
add a comment |
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You can not chain input from one query to another query like that.
Either use search query ex. Model.find(id) or aggregation framework.
Aggregation framework provides you the functionality to create a pipeline (ex. match,unwind,lookup,project).
To utilize mongodb indexing always try to use "$match" first in the pipeline
match = { "$match" => { "dad_id" =>9} }
unwind = {"$uwind"=>"$childs"}
pipeline = [match,unwind]
collection.aggregate(pipeline).each do |obj|
end
answered Nov 22 '18 at 11:59
Mukul DevMukul Dev
814
add a comment |
0
You can not chain input from one query to another query like that.
Either use search query ex. Model.find(id) or aggregation framework.
Aggregation framework provides you the functionality to create a pipeline (ex. match,unwind,lookup,project).
To utilize mongodb indexing always try to use "$match" first in the pipeline
match = { "$match" => { "dad_id" =>9} }
unwind = {"$uwind"=>"$childs"}
pipeline = [match,unwind]
collection.aggregate(pipeline).each do |obj|
end
answered Nov 22 '18 at 11:59
Mukul DevMukul Dev
814
add a comment |
0
0
0
You can not chain input from one query to another query like that.
Either use search query ex. Model.find(id) or aggregation framework.
Aggregation framework provides you the functionality to create a pipeline (ex. match,unwind,lookup,project).
To utilize mongodb indexing always try to use "$match" first in the pipeline
match = { "$match" => { "dad_id" =>9} }
unwind = {"$uwind"=>"$childs"}
pipeline = [match,unwind]
collection.aggregate(pipeline).each do |obj|
end
answered Nov 22 '18 at 11:59
Mukul DevMukul Dev
814
You can not chain input from one query to another query like that.
Either use search query ex. Model.find(id) or aggregation framework.
Aggregation framework provides you the functionality to create a pipeline (ex. match,unwind,lookup,project).
To utilize mongodb indexing always try to use "$match" first in the pipeline
match = { "$match" => { "dad_id" =>9} }
unwind = {"$uwind"=>"$childs"}
pipeline = [match,unwind]
collection.aggregate(pipeline).each do |obj|
end
answered Nov 22 '18 at 11:59
Mukul DevMukul Dev
814
answered Nov 22 '18 at 11:59
Mukul DevMukul Dev
814
answered Nov 22 '18 at 11:59
Mukul DevMukul Dev
814
answered Nov 22 '18 at 11:59
Mukul DevMukul Dev
814
814
add a comment |
add a comment |
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Which driver is this? You should not even be able to do that. It's certainly not standard with any other language driver and since it is not working, then this "feature" is not even implemented properly. You're supposed to use a
$matchstage in the aggregation pipeline. And MongoDB "views" are something completely different.– Neil Lunn
Nov 22 '18 at 10:54
Yeah about the view your are right, I am calling them poorly. I will edit the question. The driver any way is ruby. My question remain the same but change the word view with "dataset"
– ciaoben
Nov 22 '18 at 10:56
It's not a matter of what you are calling it, but rather that no officially supported driver has any such feature as you are claiming. So what you need to tell us is "where did you install this driver from?"
– Neil Lunn
Nov 22 '18 at 10:58
@NeilLunn it is the official gem "mongo" version 2.3.0
– ciaoben
Nov 22 '18 at 11:01
Yeah was just looking at it and it's pretty bad that this is exposed this way. As stated, you are not actually meant to even try and use it that way, and no other language driver even allows it. Instead you
$matchin the pipeline itselfcollection.aggregate([{ "$match" => { dad_id: 9 } },{ "$unwind"=> "$childs" }]). So the "bugginess" in the driver is thefind()returns a "Collection View" which exposes anaggregate()method which should not actually be there. Do it with theCollectionmethod like everyone else does.– Neil Lunn
Nov 22 '18 at 11:12