BigQuery API - Class Google::Cloud::Bigquery::External::BigtableSource (v1.41.0)

Reference documentation and code samples for the BigQuery API class Google::Cloud::Bigquery::External::BigtableSource.

BigtableSource

BigtableSource is a subclass of DataSource and represents a Bigtable external data source that can be queried from directly, even though the data is not stored in BigQuery. Instead of loading or streaming the data, this object references the external data source.

Inherits

Example

require "google/cloud/bigquery"

bigquery = Google::Cloud::Bigquery.new

bigtable_url = "https://googleapis.com/bigtable/projects/..."
bigtable_table = bigquery.external bigtable_url do |bt|
  bt.rowkey_as_string = true
  bt.add_family "user" do |u|
    u.add_string "name"
    u.add_string "email"
    u.add_integer "age"
    u.add_boolean "active"
  end
end

data = bigquery.query "SELECT * FROM my_ext_table",
                      external: { my_ext_table: bigtable_table }

# Iterate over the first page of results
data.each do |row|
  puts row[:name]
end
# Retrieve the next page of results
data = data.next if data.next?

Methods

#add_family

def add_family(family_id, encoding: nil, latest: nil, type: nil) { |family| ... } -> BigtableSource::ColumnFamily

Add a column family to expose in the table schema along with its types. Columns belonging to the column family may also be exposed.

Parameters
  • family_id (String) — Identifier of the column family. See ColumnFamily#family_id.
  • encoding (String) (defaults to: nil) — The encoding of the values when the type is not STRING. See ColumnFamily#encoding.
  • latest (Boolean) (defaults to: nil) — Whether only the latest version of value are exposed for all columns in this column family. See ColumnFamily#latest.
  • type (String) (defaults to: nil) — The type to convert the value in cells of this column. See ColumnFamily#type.
Yields
  • (family) — a block for setting the family
Yield Parameter
Returns
Example 
require "google/cloud/bigquery"

bigquery = Google::Cloud::Bigquery.new

bigtable_url = "https://googleapis.com/bigtable/projects/..."
bigtable_table = bigquery.external bigtable_url do |bt|
  bt.rowkey_as_string = true
  bt.add_family "user" do |u|
    u.add_string "name"
    u.add_string "email"
    u.add_integer "age"
    u.add_boolean "active"
  end
end

#families

def families() -> Array<BigtableSource::ColumnFamily>

List of column families to expose in the table schema along with their types. This list restricts the column families that can be referenced in queries and specifies their value types. You can use this list to do type conversions - see ColumnFamily#type for more details. If you leave this list empty, all column families are present in the table schema and their values are read as BYTES. During a query only the column families referenced in that query are read from Bigtable.

Returns
Example 
require "google/cloud/bigquery"

bigquery = Google::Cloud::Bigquery.new

bigtable_url = "https://googleapis.com/bigtable/projects/..."
bigtable_table = bigquery.external bigtable_url do |bt|
  bt.rowkey_as_string = true
  bt.add_family "user" do |u|
    u.add_string "name"
    u.add_string "email"
    u.add_integer "age"
    u.add_boolean "active"
  end
end

bigtable_table.families.count #=> 1

#rowkey_as_string

def rowkey_as_string() -> Boolean

Whether the rowkey column families will be read and converted to string. Otherwise they are read with BYTES type values and users need to manually cast them with CAST if necessary. The default value is false.

Returns
  • (Boolean)
Example 
require "google/cloud/bigquery"

bigquery = Google::Cloud::Bigquery.new

bigtable_url = "https://googleapis.com/bigtable/projects/..."
bigtable_table = bigquery.external bigtable_url do |bt|
  bt.rowkey_as_string = true
end

bigtable_table.rowkey_as_string #=> true

#rowkey_as_string=

def rowkey_as_string=(row_rowkey)

Set the number of rows at the top of a sheet that BigQuery will skip when reading the data.

Parameter
  • row_rowkey (Boolean) — New rowkey_as_string value
Example 
require "google/cloud/bigquery"

bigquery = Google::Cloud::Bigquery.new

bigtable_url = "https://googleapis.com/bigtable/projects/..."
bigtable_table = bigquery.external bigtable_url do |bt|
  bt.rowkey_as_string = true
end

bigtable_table.rowkey_as_string #=> true