Question

我知道BigQuery现在支持CREATE TABLE ... AS SELECT...之类的标准SQL语法。但是，没有人有提供一些示例数据来生成此表的示例吗？

说我想要两列分别为 A 和 B 。 A 值应为1,2,3,4， B 值应为"Alpha", "Bravo", "Charlie", "Delta"。如何生成这样的查询并创建这样的表？我意识到这对于创建大表不是很有效，但是想知道创建小表的推荐方法。

Answer 1

select . . . union all怎么样？

create table t as
    select 1 as a, 'Alpha' as b union all
    select 2 as a, 'Bravo' as b union all
    select 3 as a, 'Charlie' as b union all
    select 4 as a, 'Delta' as b;

Answer 2

另一个不太繁琐的选择是

CREATE TABLE `PROJECT_ID.DATASET_NAME.NEW_TABLE_NAME` AS  
SELECT * FROM UNNEST([
  STRUCT(1 AS a, 'Alpha' AS b),
  (2, 'Bravo'),
  (3, 'Charlie'),
  (4, 'Delta')
])

或使其更易于与现有的CSV重复使用

CREATE TABLE `PROJECT_ID.DATASET_NAME.NEW_TABLE_NAME` AS  
SELECT * FROM UNNEST([
  STRUCT(NULL AS a, '' AS b),
  (1, 'Alpha'),
  (2, 'Bravo'),
  (3, 'Charlie'),
  (4, 'Delta')
])
WHERE NOT a IS NULL

BigQuery只需一次查询即可创建小型示例表

2 个答案: