Class: Google::Cloud::Bigquery::Data

Inherits:
Array
  • Object
show all
Defined in:
lib/google/cloud/bigquery/data.rb

Overview

Data

Represents Table Data as a list of name/value pairs. Also contains metadata such as etag and total.

Direct Known Subclasses

QueryData

Instance Method Summary collapse

Instance Method Details

#all(request_limit: nil) {|row| ... } ⇒ Enumerator

Retrieves all rows by repeatedly loading #next until #next? returns false. Calls the given block once for each row, which is passed as the parameter.

An Enumerator is returned if no block is given.

This method may make several API calls until all rows are retrieved. Be sure to use as narrow a search criteria as possible. Please use with caution.

Examples:

Iterating each rows by passing a block:

require "google/cloud/bigquery"

bigquery = Google::Cloud::Bigquery.new
dataset = bigquery.dataset "my_dataset"
table = dataset.table "my_table"

table.data.all do |row|
  puts row[:word]
end

Using the enumerator by not passing a block:

require "google/cloud/bigquery"

bigquery = Google::Cloud::Bigquery.new
dataset = bigquery.dataset "my_dataset"
table = dataset.table "my_table"

words = table.data.all.map do |row|
  row[:word]
end

Limit the number of API calls made:

require "google/cloud/bigquery"

bigquery = Google::Cloud::Bigquery.new
dataset = bigquery.dataset "my_dataset"
table = dataset.table "my_table"

table.data.all(request_limit: 10) do |row|
  puts row[:word]
end

Parameters:

  • request_limit (Integer) —

    The upper limit of API requests to make to load all data. Default is no limit.

Yields:

  • (row) —

    The block for accessing each row of data.

Yield Parameters:

  • row (Hash) —

    The row object.

Returns:

  • (Enumerator) 


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# File 'lib/google/cloud/bigquery/data.rb', line 181

def all request_limit: nil
  request_limit = request_limit.to_i if request_limit
  unless block_given?
    return enum_for(:all, request_limit: request_limit)
  end
  results = self
  loop do
    results.each { |r| yield r }
    if request_limit
      request_limit -= 1
      break if request_limit < 0
    end
    break unless results.next?
    results = results.next
  end
end

#etag ⇒ Object

The etag.



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# File 'lib/google/cloud/bigquery/data.rb', line 51

def etag
  @gapi.etag
end

#fields ⇒ Object

The fields of the data.



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# File 'lib/google/cloud/bigquery/data.rb', line 76

def fields
  schema.fields
end

#headers ⇒ Object

The name of the columns in the data.



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# File 'lib/google/cloud/bigquery/data.rb', line 82

def headers
  schema.headers
end

#kind ⇒ Object

The resource type of the API response.



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# File 'lib/google/cloud/bigquery/data.rb', line 45

def kind
  @gapi.kind
end

#next ⇒ Data

Retrieve the next page of data.

Examples:

require "google/cloud/bigquery"

bigquery = Google::Cloud::Bigquery.new
dataset = bigquery.dataset "my_dataset"
table = dataset.table "my_table"

data = table.data
if data.next?
  next_data = data.next
end

Returns:



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# File 'lib/google/cloud/bigquery/data.rb', line 124

def next
  return nil unless next?
  ensure_table!
  table.data token: token
end

#next? ⇒ Boolean

Whether there is a next page of data.

Examples:

require "google/cloud/bigquery"

bigquery = Google::Cloud::Bigquery.new
dataset = bigquery.dataset "my_dataset"
table = dataset.table "my_table"

data = table.data
if data.next?
  next_data = data.next
end

Returns:

  • (Boolean) 


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# File 'lib/google/cloud/bigquery/data.rb', line 103

def next?
  !token.nil?
end

#schema ⇒ Object

The schema of the data.



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# File 'lib/google/cloud/bigquery/data.rb', line 70

def schema
  table.schema
end

#token ⇒ Object

A token used for paging results.



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# File 'lib/google/cloud/bigquery/data.rb', line 57

def token
  @gapi.page_token
end

#total ⇒ Object

The total number of rows in the complete table.



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# File 'lib/google/cloud/bigquery/data.rb', line 62

def total
  Integer @gapi.total_rows
rescue
  nil
end