BigQueryのschemaが少しわかりやすくなるくん

bq2json.rb

# ruby bq2json.rb <(bq show --format json 'project:dataset.table') | gron

require 'json'

schema = JSON.parse(IO.binread(ARGV.shift))['schema']

def dfs obj
  res = {}
  obj['fields'].map do |obj|
    case obj['type']
    when 'STRING'
      res[obj['name']] = 'S'
    when 'FLOAT'
      res[obj['name']] = 'F'
    when 'INTEGER'
      res[obj['name']] = 'I'
    when 'BOOLEAN'
      res[obj['name']] = 'B'
    when 'TIMESTAMP'
      res[obj['name']] = 'T'
    when 'RECORD'
      res[obj['name']] = dfs obj
    else
      raise obj['type']
    end
  end

  res
end

puts JSON.dump(dfs(schema))