regex - 使用正则表达式从 Google BigQuery 中的字符串中提取数字

Question

我想知道我是否可以在 BigQuery 中使用正则表达式从字符串中提取所有数字。

我认为下面的方法有效，但只返回第一个命中 - 有没有办法提取所有命中。

我在这里的用例是，我基本上想从 url 中获取最大的数字，因为它更像是我需要加入的 post_id。

这是我正在谈论的例子:

SELECT
  mystr,
  REGEXP_EXTRACT(mystr, r'(\d+)') AS nums
FROM
  (SELECT 'this is a string with some 666 numbers 999 in it 333' AS mystr),
  (SELECT 'just one number 123 in this one ' AS mystr),
  (SELECT '99' AS mystr),
  (SELECT 'another -2 example 99' AS mystr),
  (SELECT 'another-8766 example 99' AS mystr),
  (SELECT 'http://somedomain.com/2015/12/this-is-a-post-with-id-in-url-99999' AS mystr),
  (SELECT 'http://somedomain.com/2015/12/this-is-a-post-with-id-in-url-99999/gallery/001' AS mystr),
  (SELECT 'http://somedomain.com/2015/12/this-is-a-post-with-id-in-url-99999/print-preview' AS mystr)

我从中得到的结果是:

[
  {
    "mystr": "this is a string with some 666 numbers 999 in it 333",
    "nums": "666"
  },
  {
    "mystr": "just one number 123 in this one ",
    "nums": "123"
  },
  {
    "mystr": "99",
    "nums": "99"
  },
  {
    "mystr": "another -2 example 99",
    "nums": "2"
  },
  {
    "mystr": "another-8766 example 99",
    "nums": "8766"
  },
  {
    "mystr": "http://somedomain.com/2015/12/this-is-a-post-with-id-in-url-99999",
    "nums": "2015"
  },
  {
    "mystr": "http://somedomain.com/2015/12/this-is-a-post-with-id-in-url-99999/gallery/001",
    "nums": "2015"
  },
  {
    "mystr": "http://somedomain.com/2015/12/this-is-a-post-with-id-in-url-99999/print-preview",
    "nums": "2015"
  }
]

Answer 1

经过一番挖掘，我最终得到了这个解决方案:

SELECT
  mystr,
  GROUP_CONCAT(SPLIT(REGEXP_REPLACE(mystr, r'[^\d]+', ','))) AS nums
FROM
  (SELECT 'this is a string with some 666 numbers 999 in it 333' AS mystr),
  (SELECT 'just one number 123 in this one ' AS mystr),
  (SELECT '99' AS mystr),
  (SELECT 'another -2 example 99' AS mystr),
  (SELECT 'another-8766 example 99' AS mystr),
  (SELECT 'http://somedomain.com/2015/12/this-is-a-post-with-id-in-url-99999' AS mystr),
  (SELECT 'http://somedomain.com/2015/12/this-is-a-post-with-id-in-url-99999/gallery/001' AS mystr),
  (SELECT 'http://somedomain.com/2015/12/this-is-a-post-with-id-in-url-99999/print-preview' AS mystr)

工作原理:

• 我首先使用正则表达式匹配任何非数字并用逗号替换
• 然后使用split得到结果，空的结果被丢弃
• group_concat 这里只是展示结果