Question

我从BigQuery开始，在pSQl方面有一些经验。我正在成功运行的#legacySQL查询是：

SELECT
    FIRST(SPLIT(ewTerms, '/')) AS place,
    NTH(2, SPLIT(ewTerms, '/')) AS divisor
FROM (SELECT ewTerms FROM account.free)

表'free'中'ewTerms'列中的字符串值是单个数字分数，例如“2/4”，“3/5”等。这个#legacySQl查询从'ewTerms成功创建两列'，阅读：

Row place divisor
1   3   5
2   2   4

我现在需要在WITH函数中使用此列创建，因此我必须切换到使用#standardSQL。谁能告诉我如何使用#standardSQL调用字符串的FIRST（）和NTH（）函数？我试过了：

WITH prep AS(
        SELECT 
            SPLIT(ewTerms, '/') AS split
        FROM (SELECT ewTerms FROM accounts.free)
    )

SELECT 
    split[SAFE_ORDINAL(1)] AS place,
    split[SAFE_ORDINAL(2)] AS divisor
FROM prep

但这是错误的。帮助任何人？

Answer 1

你的问题不清楚是什么问题。此查询适用于我：

#standardSQL
WITH Input AS (
  SELECT '3/5' AS ewTerms UNION ALL
  SELECT '2/4' AS ewTerms
), prep AS (
  SELECT 
    SPLIT(ewTerms, '/') AS split
  FROM Input
)
SELECT 
  split[SAFE_ORDINAL(1)] AS place,
  split[SAFE_ORDINAL(2)] AS divisor
FROM prep;

输出结果为：

+-------+---------+
| place | divisor |
+-------+---------+
| 2     | 4       |
| 3     | 5       |
+-------+---------+

使用原始表格，您的查询将是：

#standardSQL
WITH prep AS (
  SELECT 
    SPLIT(ewTerms, '/') AS split
  FROM accounts.free
)
SELECT 
  split[SAFE_ORDINAL(1)] AS place,
  split[SAFE_ORDINAL(2)] AS divisor
FROM prep;

BigQuery的StandardSQL NTH（）和FIRST（）函数

1 个答案: