BigQuery 在一个查询中创建小样本表

Question

我知道 BigQuery 现在支持 CREATE TABLE ... AS SELECT... 类似标准 SQL 的语法。但是有没有人提供一些示例数据来生成这个表的例子？

假设我想要两个名为 A 和 B 的列。 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？我知道这对于创建大表效率不高，但想知道创建小表的推荐方法。

Answer 1

另一个不那么冗长的选项是

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')
])   

或者让它更容易与现有的 csv 一起重用

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

Answer 2

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;