Question

通常，WITH语句具有以下form

WITH subQ1 AS (SELECT SchoolID FROM Roster),
     subQ2 AS (SELECT OpponentID FROM PlayerStats)
SELECT * FROM subQ1
UNION ALL
SELECT * FROM subQ2;

现在我想知道是否可以做这样的事情：

WITH
  relevant_ids AS (SELECT ids FROM table WHERE condition),
  actual_data AS (SELECT stuff FROM large_table WHERE id in relevant_ids)

我知道我可以使用第一个查询并将其直接放在第二个查询的where条件中，但是我觉得这不太容易阅读。

Answer 1

要专门解决您的第二个查询...

WITH
  relevant_ids AS (SELECT id FROM table WHERE condition),
  actual_data AS (SELECT stuff FROM large_table WHERE id in (select id from relevant_ids))
SELECT * from actual_data

CTE中的代码仍必须是有效的SQL。

但是，请考虑仅使用联接。

WITH
  relevant_ids AS (SELECT id FROM table WHERE condition)
SELECT 
  large_table.stuff 
FROM large_table 
INNER JOIN relevant_ids USING(id)

BigQuery-WITH语句-在后续子查询中的WHERE条件下引用早期子查询

1 个答案: