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Cloud Firestore API - Class Google::Cloud::Firestore::Query (v2.8.0)

Reference documentation and code samples for the Cloud Firestore API class Google::Cloud::Firestore::Query.

Query

Represents a query to the Firestore API.

Instances of this class are immutable. All methods that refine the query return new instances.

Inherits

Object

Examples

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Create a query
query = firestore.col(:cities).select(:population)

query.get do |city|
  puts "#{city.document_id} has #{city[:population]} residents."
end

Listen to a query for changes:

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Create a query
query = firestore.col(:cities).order(:population, :desc)

listener = query.listen do |snapshot|
  puts "The query snapshot has #{snapshot.docs.count} documents "
  puts "and has #{snapshot.changes.count} changes."
end

# When ready, stop the listen operation and close the stream.
listener.stop

Methods

.from_json

def self.from_json(json, client) -> Query

Deserializes a JSON text string serialized from this class and returns it as a new instance. See also #to_json.

Parameters

json (String) — A JSON text string serialized using #to_json.
client (Google::Cloud::Firestore::Client) — A connected client instance.

Returns

(Query) — A new query equal to the original query used to create the JSON text string.

Raises

(ArgumentError)

Example

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new
query = firestore.col(:cities).select(:population)

json = query.to_json

new_query = Google::Cloud::Firestore::Query.from_json json, firestore

new_query.get do |city|
  puts "#{city.document_id} has #{city[:population]} residents."
end

#aggregate_query

def aggregate_query() -> AggregateQuery

Creates an AggregateQuery object for the query.

Returns

(AggregateQuery) — New empty aggregate query.

Example

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Get a collection reference
query = firestore.col "cities"

# Create an aggregate query
aggregate_query = query.aggregate_query

#end_at

def end_at(*values) -> Query

Ends query results at a set of field values. The field values can be specified explicitly as arguments, or can be specified implicitly by providing a DocumentSnapshot object instead. The result set will include the document specified by values.

If the current query already has specified end_before or end_at, this will overwrite it.

The values are associated with the field paths that have been provided to order, and must match the same sort order. An ArgumentError will be raised if more explicit values are given than are present in order.

Parameter

values (DocumentSnapshot, Object, Array<Object>) — The field values to end the query at.

Returns

(Query) — New query with end_at called on it.

Raises

(ArgumentError)

Examples

Ending a query at a document reference id

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Get a collection reference
cities_col = firestore.col "cities"
nyc_doc_id = "NYC"

# Create a query
query = cities_col.order(firestore.document_id)
                  .end_at(nyc_doc_id)

query.get do |city|
  puts "#{city.document_id} has #{city[:population]} residents."
end

Ending a query at a document reference object

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Get a collection reference
cities_col = firestore.col "cities"
nyc_doc_id = "NYC"
nyc_ref = cities_col.doc nyc_doc_id

# Create a query
query = cities_col.order(firestore.document_id)
                  .end_at(nyc_ref)

query.get do |city|
  puts "#{city.document_id} has #{city[:population]} residents."
end

Ending a query at multiple explicit values

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Get a collection reference
cities_col = firestore.col "cities"

# Create a query
query = cities_col.order(:population, :desc)
                  .order(:name)
                  .end_at(1000000, "New York City")

query.get do |city|
  puts "#{city.document_id} has #{city[:population]} residents."
end

Ending a query at a DocumentSnapshot

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Get a collection reference
cities_col = firestore.col "cities"

# Get a document snapshot
nyc_snap = firestore.doc("cities/NYC").get

# Create a query
query = cities_col.order(:population, :desc)
                  .order(:name)
                  .end_at(nyc_snap)

query.get do |city|
  puts "#{city.document_id} has #{city[:population]} residents."
end

#end_before

def end_before(*values) -> Query

Ends query results before a set of field values. The field values can be specified explicitly as arguments, or can be specified implicitly by providing a DocumentSnapshot object instead. The result set will not include the document specified by values.

If the current query already has specified end_before or end_at, this will overwrite it.

Parameter

values (DocumentSnapshot, Object, Array<Object>) — The field values to end the query before.

Returns

(Query) — New query with end_before called on it.

Raises

(ArgumentError)

Examples

Ending a query before a document reference id

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Get a collection reference
cities_col = firestore.col "cities"
nyc_doc_id = "NYC"

# Create a query
query = cities_col.order(firestore.document_id)
                  .end_before(nyc_doc_id)

query.get do |city|
  puts "#{city.document_id} has #{city[:population]} residents."
end

Ending a query before a document reference object

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Get a collection reference
cities_col = firestore.col "cities"
nyc_doc_id = "NYC"
nyc_ref = cities_col.doc nyc_doc_id

# Create a query
query = cities_col.order(firestore.document_id)
                  .end_before(nyc_ref)

query.get do |city|
  puts "#{city.document_id} has #{city[:population]} residents."
end

Ending a query before multiple explicit values

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Get a collection reference
cities_col = firestore.col "cities"

# Create a query
query = cities_col.order(:population, :desc)
                  .order(:name)
                  .end_before(1000000, "New York City")

query.get do |city|
  puts "#{city.document_id} has #{city[:population]} residents."
end

Ending a query before a DocumentSnapshot

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Get a collection reference
cities_col = firestore.col "cities"

# Get a document snapshot
nyc_snap = firestore.doc("cities/NYC").get

# Create a query
query = cities_col.order(:population, :desc)
                  .order(:name)
                  .end_before(nyc_snap)

query.get do |city|
  puts "#{city.document_id} has #{city[:population]} residents."
end

#get

def get() { |document| ... } -> Enumerator<DocumentSnapshot>

Aliases

#run

Retrieves document snapshots for the query.

Yields

(documents) — The block for accessing the document snapshots.

Yield Parameter

document (DocumentSnapshot) — A document snapshot.

Returns

(Enumerator<DocumentSnapshot>) — A list of document snapshots.

Example

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Get a collection reference
cities_col = firestore.col "cities"

# Create a query
query = cities_col.select(:population)

query.get do |city|
  puts "#{city.document_id} has #{city[:population]} residents."
end

#limit

def limit(num) -> Query

Limits a query to return only the first matching documents.

If the current query already has a limit set, this will overwrite it.

Parameter

num (Integer) — The maximum number of results to return.

Returns

(Query) — New query with limit called on it.

Example

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Get a collection reference
cities_col = firestore.col "cities"

# Create a query
query = cities_col.order(:name, :desc).offset(10).limit(5)

query.get do |city|
  puts "#{city.document_id} has #{city[:population]} residents."
end

#limit_to_last

def limit_to_last(num) -> Query

Limits a query to return only the last matching documents.

You must specify at least one "order by" clause for limitToLast queries. (See #order.)

Results for limit_to_last queries are only available once all documents are received. Hence, limit_to_last queries cannot be streamed using #listen.

Parameter

num (Integer) — The maximum number of results to return.

Returns

(Query) — New query with limit_to_last called on it.

Example

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Get a collection reference
cities_col = firestore.col "cities"

# Create a query
query = cities_col.order(:name, :desc).limit_to_last(5)

query.get do |city|
  puts "#{city.document_id} has #{city[:population]} residents."
end

#listen

def listen(&callback) { |snapshot| ... } -> QueryListener

Aliases

#on_snapshot

Listen to this query for changes.

Yields

(callback) — The block for accessing the query snapshot.

Yield Parameter

snapshot (QuerySnapshot) — A query snapshot.

Returns

(QueryListener) — The ongoing listen operation on the query.

Raises

(ArgumentError)

Example

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Create a query
query = firestore.col(:cities).order(:population, :desc)

listener = query.listen do |snapshot|
  puts "The query snapshot has #{snapshot.docs.count} documents "
  puts "and has #{snapshot.changes.count} changes."
end

# When ready, stop the listen operation and close the stream.
listener.stop

#offset

def offset(num) -> Query

Skips to an offset in a query. If the current query already has specified an offset, this will overwrite it.

Parameter

num (Integer) — The number of results to skip.

Returns

(Query) — New query with offset called on it.

Example

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Get a collection reference
cities_col = firestore.col "cities"

# Create a query
query = cities_col.limit(5).offset(10)

query.get do |city|
  puts "#{city.document_id} has #{city[:population]} residents."
end

#on_snapshot

def on_snapshot(&callback) { |snapshot| ... } -> QueryListener

Alias Of: #listen

Listen to this query for changes.

Yields

(callback) — The block for accessing the query snapshot.

Yield Parameter

snapshot (QuerySnapshot) — A query snapshot.

Returns

(QueryListener) — The ongoing listen operation on the query.

Raises

(ArgumentError)

Example

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Create a query
query = firestore.col(:cities).order(:population, :desc)

listener = query.listen do |snapshot|
  puts "The query snapshot has #{snapshot.docs.count} documents "
  puts "and has #{snapshot.changes.count} changes."
end

# When ready, stop the listen operation and close the stream.
listener.stop

#order

def order(field, direction = :asc) -> Query

Aliases

#order_by

Specifies an "order by" clause on a field.

Parameters

field (FieldPath, String, Symbol) — A field path to order results with.

If a FieldPath object is not provided then the field will be treated as a dotted string, meaning the string represents individual fields joined by ".". Fields containing ~, *, /, [, ], and . cannot be in a dotted string, and should provided using a FieldPath object instead.
direction (String, Symbol) — The direction to order the results by. Values that start with "a" are considered ascending. Values that start with "d" are considered descending. Default is ascending. Optional.

Returns

(Query) — New query with order called on it.

Examples

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Get a collection reference
cities_col = firestore.col "cities"

# Create a query
query = cities_col.order(:name)

query.get do |city|
  puts "#{city.document_id} has #{city[:population]} residents."
end

Order by name descending:

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Get a collection reference
cities_col = firestore.col "cities"

# Create a query
query = cities_col.order(:name, :desc)

query.get do |city|
  puts "#{city.document_id} has #{city[:population]} residents."
end

#order_by

def order_by(field, direction = :asc) -> Query

Alias Of: #order

Specifies an "order by" clause on a field.

Parameters

field (FieldPath, String, Symbol) — A field path to order results with.

If a FieldPath object is not provided then the field will be treated as a dotted string, meaning the string represents individual fields joined by ".". Fields containing ~, *, /, [, ], and . cannot be in a dotted string, and should provided using a FieldPath object instead.
direction (String, Symbol) — The direction to order the results by. Values that start with "a" are considered ascending. Values that start with "d" are considered descending. Default is ascending. Optional.

Returns

(Query) — New query with order called on it.

Examples

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Get a collection reference
cities_col = firestore.col "cities"

# Create a query
query = cities_col.order(:name)

query.get do |city|
  puts "#{city.document_id} has #{city[:population]} residents."
end

Order by name descending:

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Get a collection reference
cities_col = firestore.col "cities"

# Create a query
query = cities_col.order(:name, :desc)

query.get do |city|
  puts "#{city.document_id} has #{city[:population]} residents."
end

#run

def run() { |document| ... } -> Enumerator<DocumentSnapshot>

Alias Of: #get

Retrieves document snapshots for the query.

Yields

(documents) — The block for accessing the document snapshots.

Yield Parameter

document (DocumentSnapshot) — A document snapshot.

Returns

(Enumerator<DocumentSnapshot>) — A list of document snapshots.

Example

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Get a collection reference
cities_col = firestore.col "cities"

# Create a query
query = cities_col.select(:population)

query.get do |city|
  puts "#{city.document_id} has #{city[:population]} residents."
end

#select

def select(*fields) -> Query

Restricts documents matching the query to return only data for the provided fields.

Parameter

fields (FieldPath, String, Symbol, Array<FieldPath|String|Symbol>) — A field path to filter results with and return only the specified fields. One or more field paths can be specified.

If a FieldPath object is not provided then the field will be treated as a dotted string, meaning the string represents individual fields joined by ".". Fields containing ~, *, /, [, ], and . cannot be in a dotted string, and should provided using a FieldPath object instead.

Returns

(Query) — New query with select called on it.

Example

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Get a collection reference
cities_col = firestore.col "cities"

# Create a query
query = cities_col.select(:population)

query.get do |city|
  puts "#{city.document_id} has #{city[:population]} residents."
end

#start_after

def start_after(*values) -> Query

Starts query results after a set of field values. The field values can be specified explicitly as arguments, or can be specified implicitly by providing a DocumentSnapshot object instead. The result set will not include the document specified by values.

If the current query already has specified start_at or start_after, this will overwrite it.

Parameter

values (DocumentSnapshot, Object, Array<Object>) — The field values to start the query after.

Returns

(Query) — New query with start_after called on it.

Raises

(ArgumentError)

Examples

Starting a query after a document reference id

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Get a collection reference
cities_col = firestore.col "cities"
nyc_doc_id = "NYC"

# Create a query
query = cities_col.order(firestore.document_id)
                  .start_after(nyc_doc_id)

query.get do |city|
  puts "#{city.document_id} has #{city[:population]} residents."
end

Starting a query after a document reference object

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Get a collection reference
cities_col = firestore.col "cities"
nyc_doc_id = "NYC"
nyc_ref = cities_col.doc nyc_doc_id

# Create a query
query = cities_col.order(firestore.document_id)
                  .start_after(nyc_ref)

query.get do |city|
  puts "#{city.document_id} has #{city[:population]} residents."
end

Starting a query after multiple explicit values

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Get a collection reference
cities_col = firestore.col "cities"

# Create a query
query = cities_col.order(:population, :desc)
                  .order(:name)
                  .start_after(1000000, "New York City")

query.get do |city|
  puts "#{city.document_id} has #{city[:population]} residents."
end

Starting a query after a DocumentSnapshot

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Get a collection reference
cities_col = firestore.col "cities"

# Get a document snapshot
nyc_snap = firestore.doc("cities/NYC").get

# Create a query
query = cities_col.order(:population, :desc)
                  .order(:name)
                  .start_after(nyc_snap)

query.get do |city|
  puts "#{city.document_id} has #{city[:population]} residents."
end

#start_at

def start_at(*values) -> Query

Starts query results at a set of field values. The field values can be specified explicitly as arguments, or can be specified implicitly by providing a DocumentSnapshot object instead. The result set will include the document specified by values.

If the current query already has specified start_at or start_after, this will overwrite it.

Parameter

values (DocumentSnapshot, Object, Array<Object>) — The field values to start the query at.

Returns

(Query) — New query with start_at called on it.

Raises

(ArgumentError)

Examples

Starting a query at a document reference id

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Get a collection reference
cities_col = firestore.col "cities"
nyc_doc_id = "NYC"

# Create a query
query = cities_col.order(firestore.document_id)
                  .start_at(nyc_doc_id)

query.get do |city|
  puts "#{city.document_id} has #{city[:population]} residents."
end

Starting a query at a document reference object

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Get a collection reference
cities_col = firestore.col "cities"
nyc_doc_id = "NYC"
nyc_ref = cities_col.doc nyc_doc_id

# Create a query
query = cities_col.order(firestore.document_id)
                  .start_at(nyc_ref)

query.get do |city|
  puts "#{city.document_id} has #{city[:population]} residents."
end

Starting a query at multiple explicit values

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Get a collection reference
cities_col = firestore.col "cities"

# Create a query
query = cities_col.order(:population, :desc)
                  .order(:name)
                  .start_at(1000000, "New York City")

query.get do |city|
  puts "#{city.document_id} has #{city[:population]} residents."
end

Starting a query at a DocumentSnapshot

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Get a collection reference
cities_col = firestore.col "cities"

# Get a document snapshot
nyc_snap = firestore.doc("cities/NYC").get

# Create a query
query = cities_col.order(:population, :desc)
                  .order(:name)
                  .start_at(nyc_snap)

query.get do |city|
  puts "#{city.document_id} has #{city[:population]} residents."
end

#to_json

def to_json(options = nil) -> String

Serializes the instance to a JSON text string. See also Query.from_json.

Returns

(String) — A JSON text string.

Example

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new
query = firestore.col(:cities).select(:population)

json = query.to_json

new_query = Google::Cloud::Firestore::Query.from_json json, firestore

new_query.get do |city|
  puts "#{city.document_id} has #{city[:population]} residents."
end

#where

def where(field, operator, value) -> Query

Filters the query on a field.

Parameters

field (FieldPath, String, Symbol) — A field path to filter results with.

If a FieldPath object is not provided then the field will be treated as a dotted string, meaning the string represents individual fields joined by ".". Fields containing ~, *, /, [, ], and . cannot be in a dotted string, and should provided using a FieldPath object instead.
operator (String, Symbol) —
The operation to compare the field to. Acceptable values include:
- less than: <, lt
- less than or equal: <=, lte
- greater than: >, gt
- greater than or equal: >=, gte
- equal: =, ==, eq, eql, is
- not equal: !=
- in: in
- not in: not-in, not_in
- array contains: array-contains, array_contains
value (Object) — A value the field is compared to.

Returns

(Query) — New query with where called on it.

Example

require "google/cloud/firestore"

firestore = Google::Cloud::Firestore.new

# Get a collection reference
cities_col = firestore.col "cities"

# Create a query
query = cities_col.where(:population, :>=, 1000000)

query.get do |city|
  puts "#{city.document_id} has #{city[:population]} residents."
end