Is there a way to select table_id in a Bigquery Table Wildcard Query

Question

I have a set of day-sharded data where individual entries do not contain the day. I would like to use table wildcards to select all available data and get back data that is

Answer 1

This functionality is available now in BigQuery through _TABLE_SUFFIX pseudocolumn. Full documentation is at https://cloud.google.com/bigquery/docs/querying-wildcard-tables. Couple of things to note:

• You will need to use Standard SQL to enable table wildcards

• You will have to rename _TABLE_SUFFIX into something else in your SELECT list, i.e. following example illustrates it

  SELECT _TABLE_SUFFIX as table_id, ... FROM `MyDataset.MyTablePrefix_*`

Answer 2

Not available today, but something I'd love to have too. The team takes feature requests seriously, so thanks for adding support for this one :).

In the meantime, a workaround is doing a manual union of a SELECT of each table, plus an additional column with the date data.

For example, instead of:

SELECT x, #TABLE_ID
FROM table201401, table201402, table201303

You could do:

SELECT x, month
FROM
  (SELECT x, '201401' AS month FROM table201401),
  (SELECT x, '201402' AS month FROM table201402),
  (SELECT x, '201403' AS month FROM table201403)