In Google BigQuery we can define named subqueries via
WITH clauses are a very comfortable way to structure complex queries as it allows to reference those queries like actual tables later on.
Note: BigQuery also supports actcual temporary tables via
CREATE TEMPORARY TABLE. See the official documention on
temporary tables for further infos.
This is out of scope for this snippet, though.
WITH filtered_data as ( SELECT id FROM table WHERE id BETWEEN 5 and 10 ) SELECT * FROM filtered_data
Run on BigQuery
- Gist on Github
- Example on BigQuery
- Answer to "How to create temporary table in Google BigQuery" on Stackoverflow
Named subqueries are a great way to structure complex queries and give sub-results a meaningful name. When working with partitioned tables, I always use temporary tables via WITH to make sure I restrict the query to scan only a limited number of partitions.
DECLARE from_date TIMESTAMP DEFAULT "2018-04-09"; DECLARE to_date TIMESTAMP DEFAULT "2018-04-10"; WITH huge_table_partition as( SELECT * FROM huge_table WHERE _PARTITIONTIME BETWEEN from_date AND to_date ) SELECT * FROM huge_table_partition
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