suddenly asks, “Hey, can you give me yesterday’s number of impressions for AdWords display ads – but only in the Tokyo region?” https://cloud.google.com/files/BigQueryTechnicalWP.pdf
UNION ALL SELECT "[email protected]" AS email ) SELECT REGEXP_EXTRACT(email, r"^[a-zA-Z0-9_.+-]+") AS user_name FROM emails; https://cloud.google.com/bigquery/sql-reference/functions-and-operators#regexp_extract