I have below query that I want to convert into Mongo then How can I
SELECT COUNT(*) AS count_all, DATE(created_at) AS date_created_at FROM
"TABLE" GROUP BY DATE(created_at)
and also please explain so that next time I can do myself.
You can try the following. I hope this will help you.
db."TABLE".group({
"key": {
"created_at": true
},
"initial": {
"count_all": 0
},
"reduce": function(obj, prev) {
if (true != null) if (true instanceof Array) prev.count_all += true.length;
else prev.count_all++;
}
});
In mongodb you can use the following aggregation pipeline:
db.collection.aggregate( [
{
$group: {
_id: "$created_at",
count_all: { $sum: 1 }
}
},
{
$project: {
_id: 0, date_created_at: "$_id", count_all: 1
}
}
])
which can then be converted to ruby syntax as:
project = {"$project" =>
{
"_id" => 0,
"date_created_at" => "$_id",
"count_all" => 1
}
}
group = { "$group" =>
{ "_id" => "$created_at", "count_all" => { "$sum" => 1 } }
}
Table.collection.aggregate([group,project])
For more examples, refer the docs
Related
I have the following schema
class User
include Mongoid::Timestamps::CamelCaseCreated
include Mongoid::Timestamps::CamelCaseUpdated
embeds_many :intervals
field :name, type: String
# ...
end
class Interval
embedded_in :user
field :startTime, type: DateTime
field :endTime, type: DateTime
# ...
end
I need to get users where at least one interval has duration greater or equal to 4 hours.
So for the following data I should receive only Walter White
users = [
{
name: 'Walter White',
intervals: [
{ startTime: '2021-01-27T08:00:00Z', endTime: '2021-01-27T16:00:00Z' }
]
},
{
name: 'Jesse Pinkman',
intervals: [
{ startTime: '2021-01-27T08:00:00Z', endTime: '2021-01-27T10:00:00Z' }
{ startTime: '2021-01-27T10:00:00Z', endTime: '2021-01-27T13:00:00Z' }
]
},
{
name: 'Saul Goodman',
intervals: []
}
]
I know that on a document itself I could filter by computed field like this
User.collection.aggregate([
{ '$project' => { 'durationInMilliseconds' => { '$subtract' => ['$updatedAt', '$createdAt'] } } },
{ '$match' => { 'durationInMilliseconds' => { '$gte' => four_hours } } }
])
# or
User.where('$expr' => { '$gt' => [{ '$subtract': ['$updatedAt', '$createdAt']}, four_hours] })
I was hoping that those would work with $elemMatch, but I receive the following errors
User.where(
intervals: {
'$elemMatch' => [
{ '$project' => { 'durationInMilliseconds' => { '$subtract' => ['$endTime', '$startTime'] } } },
{ '$match' => { 'durationInMilliseconds' => { '$gt' => four_hours } } }
]
}
)
=> $elemMatch needs an Object
User.where(
intervals: {
'$elemMatch' => {
{ '$expr' => { '$max' => some_logic_here } },
}
}
)
=> $expr can only be applied to the top-level document
Is there a way to make it work with the embedded collection?
versions that I'm using:
gem mongo (2.10.2)
gem mongoid (6.1.1)
mongo --version - 4.2.9
I am trying to get the date parsed into a string format as month and numerical year format like "JAN, 92". My mapping is as below:
size" => 0,
"query" => {
"bool" => {
"must" => [
{
"term" => {
"checkin_progress_for" => {
"value" => "Goal"
}
}
},
{
"term" => {
"goal_owner_id" => {
"value" => "#{current_user.access_key}"
}
}
}
]
}
},
"aggregations" => {
"chekins_over_time" => {
"range" => {
"field" => "checkin_at",
"format" => "MMM, YY",
"ranges" => [
{
"from" => "now-6M",
"to" => "now"
}
]
},
"aggs" => {
"checkins_monthly" => {
"date_histogram" => {
"field" => "checkin_at",
"format" => "MMM, YY",
"interval" => "month",
"min_doc_count" => 0,
"missing" => 0,
"extended_bounds" => {
"min" => "now-6M",
"max" => "now"
}
}
}
}
}
}
}
I throws the following error:
elasticsearch.transport.RemoteTransportException: [captia-america][127.0.0.1:9300][indices:data/read/search[phase/query]]
Caused by: elasticsearch.ElasticsearchParseException: failed to parse date field [0] with format [MMM, YY]
If I remove the {MMM, YY} and put the normal date format it works.
What could the solution to rectify this.Help appreciated.
Your checkins_monthly aggregation is a bit wrong. The missing part should have the same format for the date to use when the field is missing. A 0 is not actually a date.
For example:
"aggs": {
"checkins_monthly": {
"date_histogram": {
"field": "checkin_at",
"format": "MMM, YY",
"interval": "month",
"min_doc_count": 0,
"missing": "Jan, 17",
"extended_bounds": {
"min": "now-6M",
"max": "now"
}
}
}
I was using this query to retrieve the most significant values:
keywords = Answer.search(
:size => 5,
:query => {
:match => {
:question_id => 32481
}
},
:aggregations => {
:keywords => {
:significant_terms => {
:field => 'text'
}
}
}
)
The field is :text, but it has nil values, so the answer is always:
2.1.2 :135 > keywords.map(&:text)
=> [nil, nil, nil, nil, nil]
I tried to add a filter, as the documentation suggests, but it gives me a parse error:
keywords = Answer.search(
:size => 5,
:query => {
:match => {
:question_id => 32481
},
:filtered => {
:filter => {
:exists => { :field => 'text' }
}
}
},
:aggregations => {
:keywords => {
:significant_terms => {
:field => 'text'
}
}
}
)
I've tried many combinations, with no success. How can I get only the valid text answers?
I believe your ES query should translate to something like this:
"size": 5,
"query": {
"filtered": {
"query": { "match": { "question_id" : 32481 } },
"filter": {
"exists": {
"field": "text"
}
}
}
},
"aggs": {
"keywords": {
"significant_terms": {
"field": "text"
}
}
}
meaning your "question_id" "match" should be enclosed in the "filtered" element.
I'd like make a multi query on Elasticsearch through Tire but with raw JSON
I can to a single request like this
#search = Tire.search('questions', query: {
function_score: {
query: {
bool: {
must: [
{
terms: {
interests: [2943,5106,3540,1443,3639]
}
}
]
}
},
random_score: {}
}
})
But for multiple I can't.
I'd like somthing like this, but it's not correct for now...
#search = Tire.multi_search 'questions' do
search :level2 do
query: {
function_score: {
query: {
bool: {
must: [{
terms: {
interests: [5090,2938,3062]
}}]
}
},
random_score: {}
}
}
end
end
Do you now how I could do to make it work?
Thank you
I found the solution.
Actually, in my case Search method is requiring :payload key in options params
#search = Tire.multi_search 'questions' do
search( :level1, :payload => {
query: {
function_score: {
query: {
bool: {
must: [
{
terms: {
interests: [2943,5106,3540,1443,3639]
}
},{
term: {
difficulty: 1
}
}
]
}
},
random_score: {}
}
}})
search( :level2, :payload => {
query: {
function_score: {
query: {
bool: {
must: [
{
terms: {
interests: [5160,2938,3062]
}
},{
term: {
difficulty: 2
}
}
]
}
},
random_score: {}
}
}})
end
I have an Element model that belongs to User. I am trying to calculate the following hash: how many users have element count of 1, 2, 3, etc. The approach I take is to first generate a hash of {user -> num elements}, then I sort-of invert it using a second map-reduce.
Here's what I have so far:
Element.map_reduce(%Q{
emit(this.user_id, 1);
}, %Q{
function(key, values) {
return Array.sum(values);
}
}).out(inline: true).map_reduce(%Q{
if (this.value > 1) {
emit(this.value, this._id);
}
}, %Q{
function(element_count, user_ids) {
return user_ids.length;
}
}).out(inline: true)
This gives me an "undefined method `map_reduce'" error. I couldn't find the answer in the docs. Any help would be great.
I calculated the hash using aggregate instead mapreduce, first grouping by user, and then grouping again by elements count:
Element.collection.aggregate([
{
"$group" => {
"_id" => "$user_id", "elements_count" => {"$sum" => 1}
}
},
{
"$group" => {
"_id" => "$elements_count", "users_count" => {"$sum" => 1}
}
},
{ "$project" => {
"_id" => 0,
"users_count" => '$users',
"elements_count" => '$_id',
}
}
])
This returns the following array:
[
{"users_count"=>3, "elements_count"=>2},
{"users_count"=>4, "elements_count"=>3},
...
]
If needed it can also be sorted using $sort operator