Class: Gcloud::Bigquery::View

Inherits:
Object
  • Object
show all
Defined in:
lib/gcloud/bigquery/view.rb

Overview

View

A view is a virtual table defined by a SQL query. You can query views in the browser tool, or by using a query job.

BigQuery’s views are logical views, not materialized views, which means that the query that defines the view is re-executed every time the view is queried. Queries are billed according to the total amount of data in all table fields referenced directly or indirectly by the top-level query.

require "gcloud"

gcloud = Gcloud.new
bigquery = gcloud.bigquery
dataset = bigquery.dataset "my_dataset"
view = dataset.create_view "my_view",
         "SELECT name, age FROM [proj:dataset.users]"

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ View

Create an empty Table object.



52
53
54
55
 
# File 'lib/gcloud/bigquery/view.rb', line 52

def initialize #:nodoc:
  @connection = nil
  @gapi = {}
end

Instance Attribute Details

#connection ⇒ Object

The Connection object.



44
45
46
 
# File 'lib/gcloud/bigquery/view.rb', line 44

def connection
  @connection
end

#gapi ⇒ Object

The Google API Client object.



48
49
50
 
# File 'lib/gcloud/bigquery/view.rb', line 48

def gapi
  @gapi
end

Class Method Details

.from_gapi(gapi, conn) ⇒ Object

New Table from a Google API Client object.



372
373
374
375
376
377
 
# File 'lib/gcloud/bigquery/view.rb', line 372

def self.from_gapi gapi, conn #:nodoc:
  new.tap do |f|
    f.gapi = gapi
    f.connection = conn
  end
end

Instance Method Details

#created_at ⇒ Object

The time when this table was created.

:category: Attributes



148
149
150
151
 
# File 'lib/gcloud/bigquery/view.rb', line 148

def created_at
  ensure_full_data!
  Time.at(@gapi["creationTime"] / 1000.0)
end

#data(options = {}) ⇒ Object

Runs a query to retrieve all data from the view.

Parameters

options

An optional Hash for controlling additional behavior. (Hash)

options[:max]

The maximum number of rows of data to return per page of results. Setting this flag to a small value such as 1000 and then paging through results might improve reliability when the query result set is large. In addition to this limit, responses are also limited to 10 MB. By default, there is no maximum row count, and only the byte limit applies. (Integer)

options[:timeout]

How long to wait for the query to complete, in milliseconds, before the request times out and returns. Note that this is only a timeout for the request, not the query. If the query takes longer to run than the timeout value, the call returns without any results and with QueryData#complete? set to false. The default value is 10000 milliseconds (10 seconds). (Integer)

options[:dryrun]

If set to true, BigQuery doesn’t run the job. Instead, if the query is valid, BigQuery returns statistics about the job such as how many bytes would be processed. If the query is invalid, an error returns. The default value is false. (Boolean)

options[:cache]

Whether to look for the result in the query cache. The query cache is a best-effort cache that will be flushed whenever tables in the query are modified. The default value is true. For more information, see query caching. (Boolean)

Returns

Gcloud::Bigquery::QueryData

Example

require "gcloud"

gcloud = Gcloud.new
bigquery = gcloud.bigquery
dataset = bigquery.dataset "my_dataset"
view = dataset.table "my_view"

data = view.data
data.each do |row|
  puts row["first_name"]
end
more_data = data.next if data.next?

:category: Data



329
330
331
332
333
334
335
336
337
338
 
# File 'lib/gcloud/bigquery/view.rb', line 329

def data options = {}
  sql = "SELECT * FROM #{@gapi['id']}"
  ensure_connection!
  resp = connection.query sql, options
  if resp.success?
    QueryData.from_gapi resp.data, connection
  else
    fail ApiError.from_response(resp)
  end
end

#dataset_id ⇒ Object

The ID of the Dataset containing this table.

:category: Attributes



73
74
75
 
# File 'lib/gcloud/bigquery/view.rb', line 73

def dataset_id
  @gapi["tableReference"]["datasetId"]
end

#delete ⇒ Object

Permanently deletes the table.

Returns

true if the table was deleted.

Example

require "gcloud"

gcloud = Gcloud.new
bigquery = gcloud.bigquery
dataset = bigquery.dataset "my_dataset"
table = dataset.table "my_table"

table.delete

:category: Lifecycle



360
361
362
363
364
365
366
367
368
 
# File 'lib/gcloud/bigquery/view.rb', line 360

def delete
  ensure_connection!
  resp = connection.delete_table dataset_id, table_id
  if resp.success?
    true
  else
    fail ApiError.from_response(resp)
  end
end

#description ⇒ Object

The description of the table.

:category: Attributes



129
130
131
132
 
# File 'lib/gcloud/bigquery/view.rb', line 129

def description
  ensure_full_data!
  @gapi["description"]
end

#description=(new_description) ⇒ Object

Updates the description of the table.

:category: Lifecycle



139
140
141
 
# File 'lib/gcloud/bigquery/view.rb', line 139

def description= new_description
  patch_gapi! description: new_description
end

#etag ⇒ Object

A string hash of the dataset.

:category: Attributes



109
110
111
112
 
# File 'lib/gcloud/bigquery/view.rb', line 109

def etag
  ensure_full_data!
  @gapi["etag"]
end

#expires_at ⇒ Object

The time when this table expires. If not present, the table will persist indefinitely. Expired tables will be deleted and their storage reclaimed.

:category: Attributes



160
161
162
163
164
 
# File 'lib/gcloud/bigquery/view.rb', line 160

def expires_at
  ensure_full_data!
  return nil if @gapi["expirationTime"].nil?
  Time.at(@gapi["expirationTime"] / 1000.0)
end

#fields ⇒ Object

The fields of the table.

:category: Attributes



223
224
225
226
227
228
 
# File 'lib/gcloud/bigquery/view.rb', line 223

def fields
  f = schema["fields"]
  f = f.to_hash if f.respond_to? :to_hash
  f = [] if f.nil?
  f
end

#headers ⇒ Object

The names of the columns in the table.

:category: Attributes



235
236
237
 
# File 'lib/gcloud/bigquery/view.rb', line 235

def headers
  fields.map { |f| f["name"] }
end

#location ⇒ Object

The geographic location where the table should reside. Possible values include EU and US. The default value is US.

:category: Attributes



200
201
202
203
 
# File 'lib/gcloud/bigquery/view.rb', line 200

def location
  ensure_full_data!
  @gapi["location"]
end

#modified_at ⇒ Object

The date when this table was last modified.

:category: Attributes



171
172
173
174
 
# File 'lib/gcloud/bigquery/view.rb', line 171

def modified_at
  ensure_full_data!
  Time.at(@gapi["lastModifiedTime"] / 1000.0)
end

#name ⇒ Object

The name of the table.

:category: Attributes



91
92
93
 
# File 'lib/gcloud/bigquery/view.rb', line 91

def name
  @gapi["friendlyName"]
end

#name=(new_name) ⇒ Object

Updates the name of the table.

:category: Lifecycle



100
101
102
 
# File 'lib/gcloud/bigquery/view.rb', line 100

def name= new_name
  patch_gapi! name: new_name
end

#project_id ⇒ Object

The ID of the Project containing this table.

:category: Attributes



82
83
84
 
# File 'lib/gcloud/bigquery/view.rb', line 82

def project_id
  @gapi["tableReference"]["projectId"]
end

#query ⇒ Object

The query that executes each time the view is loaded.

:category: Attributes



244
245
246
 
# File 'lib/gcloud/bigquery/view.rb', line 244

def query
  @gapi["view"]["query"] if @gapi["view"]
end

#query=(new_query) ⇒ Object

Updates the query that executes each time the view is loaded. See the BigQuery Query Reference .

Parameters

new_query

The query that defines the view. (String)

Example

require "gcloud"

gcloud = Gcloud.new
bigquery = gcloud.bigquery
dataset = bigquery.dataset "my_dataset"
view = dataset.table "my_view"

view.query = "SELECT first_name FROM [my_project:my_dataset.my_table]"

:category: Lifecycle



271
272
273
 
# File 'lib/gcloud/bigquery/view.rb', line 271

def query= new_query
  patch_gapi! query: new_query
end

#schema ⇒ Object

The schema of the table.

:category: Attributes



210
211
212
213
214
215
216
 
# File 'lib/gcloud/bigquery/view.rb', line 210

def schema
  ensure_full_data!
  s = @gapi["schema"]
  s = s.to_hash if s.respond_to? :to_hash
  s = {} if s.nil?
  s
end

#table? ⇒ Boolean

Checks if the table’s type is “TABLE”.

:category: Attributes

Returns:

  • (Boolean) 


181
182
183
 
# File 'lib/gcloud/bigquery/view.rb', line 181

def table?
  @gapi["type"] == "TABLE"
end

#table_id ⇒ Object

A unique ID for this table. The ID must contain only letters (a-z, A-Z), numbers (0-9), or underscores (_). The maximum length is 1,024 characters.

:category: Attributes



64
65
66
 
# File 'lib/gcloud/bigquery/view.rb', line 64

def table_id
  @gapi["tableReference"]["tableId"]
end

#url ⇒ Object

A URL that can be used to access the dataset using the REST API.

:category: Attributes



119
120
121
122
 
# File 'lib/gcloud/bigquery/view.rb', line 119

def url
  ensure_full_data!
  @gapi["selfLink"]
end

#view? ⇒ Boolean

Checks if the table’s type is “VIEW”.

:category: Attributes

Returns:

  • (Boolean) 


190
191
192
 
# File 'lib/gcloud/bigquery/view.rb', line 190

def view?
  @gapi["type"] == "VIEW"
end