title: Google Big Query accesses dataset in one way but not the other
body: <p>Trying to query a google big query dataset. </p>
  
  <p>When I run the following code:</p>
  
  <pre><code>from google.cloud import bigquery
  bqClient = bigquery.Client.from_service_account_json("/..../....json")
  
  query ="""
  SELECT
  CONCAT(
  'https://stackoverflow.com/questions/',
  CAST(id as STRING)) as url,
  view_count
  FROM `bigquery-public-data.stackoverflow.posts_questions`
  WHERE tags like '%google-bigquery%'
  ORDER BY view_count DESC
  LIMIT 10
  """
  #dry_run so no resources are wasted
  job_config = bigquery.QueryJobConfig(dry_run=True)
  query_job = bqClient.query(query, job_config = job_config)
  iterator = query_job.result(timeout=30)
  </code></pre>
  
  <p>Error:</p>
  
  <pre><code>File "test.py", line 40, in &lt;module&gt;
  iterator = query_job.result(timeout=30)
  File ".../python3.6/site-packages/google/cloud/bigquery/job.py", line 3129, in result
  self.job_id, retry, project=self.project, location=self.location
  File ".../python3.6/site-packages/google/cloud/bigquery/client.py", line 1112, in _get_query_results
  retry, method="GET", path=path, query_params=extra_params
  File ".../python3.6/site-packages/google/cloud/bigquery/client.py", line 487, in _call_api
  return call()
  File ".../python3.6/site-packages/google/api_core/retry.py", line 286, in retry_wrapped_func
  on_error=on_error,
  File ".../python3.6/site-packages/google/api_core/retry.py", line 184, in retry_target
  return target()
  File ".../python3.6/site-packages/google/cloud/_http.py", line 421, in api_request
  raise exceptions.from_http_response(response)
  google.api_core.exceptions.NotFound: 404 GET https://bigquery.googleapis.com/bigquery/v2/projects/projectone/queries/None?maxResults=0&amp;location=US: Not found: Job projectone:US.None
  
  (job ID: None)
  
             -----Query Job SQL Follows-----                
  
  |    .    |    .    |    .    |    .    |    .    |
  1:
  2:SELECT
  3:  CONCAT(
  4:    'https://stackoverflow.com/questions/',
  5:    CAST(id as STRING)) as url,
  6:  view_count
  7:FROM `bigquery-public-data.stackoverflow.posts_questions`
  8:WHERE tags like '%google-bigquery%'
  9:ORDER BY view_count DESC
  10:LIMIT 10
  </code></pre>
  
  <p>What is peculiar though is when I run:</p>
  
  <pre><code>client = bigquery.Client.from_service_account_json("/.../...json")
  stf_dataset_ref = client.dataset('stackoverflow', project='bigquery-public-data')
  stf_dset = client.get_dataset(stf_dataset_ref)
  print([x.table_id for x in client.list_tables(stf_dset)])
  </code></pre>
  
  <p>It returns:</p>
  
  <p>['badges', 'comments', 'post_history', 'post_links', 'posts_answers', 'posts_moderator_nomination', 'posts_orphaned_tag_wiki', 'posts_privilege_wiki', 'posts_questions', 'posts_tag_wiki', 'posts_tag_wiki_excerpt', 'posts_wiki_placeholder', 'stackoverflow_posts', 'tags', 'users', 'votes']</p>
  
  <p>Which is correct. </p>
  
  <p>Why does the latter find the dataset but not the former?</p>