正则表达式使用数字数据提取大查询

Question

how would I be able to grab the number 2627995 from this string

"hellotest/2627995?hl=en"

I want to grab the number 2627995, here is my current regex but it does not work when I use regex extract from big query

(\/)\d{7,7}

SELECT
  REGEXP_EXTRACT(DESC, r"(\/)\d{7,7}")
  AS number
FROM
  `string table`

here is the output

Thank you!!

Answer 1

I think you just want to match all digits coming after the last path separator, before either the start of the query parameter, or the end of the URL.

SELECT REGEXP_EXTRACT(DESC, r"/(\d+)(?:\?|$)") AS number
FROM `string table`

Demo

Answer 2

试试这个： r"\\/(\\d+)"

Answer 3

Your code returns the slash because you captured it (see the parentheses in (\\/)\\d{7,7} ). REGEXP_EXTRACT only returns the captured substring.

Thus, you could just wrap the other part of your regex with the parentheses:

SELECT
  REGEXP_EXTRACT(DESC, r"/(\d{7})")
  AS number
FROM
  `string table`

NOTE :

• In BigQuery, regex is specified with string literals, not regex literals (that are usually delimited with forward slashes), that is why you do not need to escape the / char (it is not a special regex metacharacter)
• {7,7} is equal to {7} limiting quantifier, meaning seven occurrences .

Also, if you are sure the number is at the end of string or is followed with a query string, you can enhance it as

REGEXP_EXTRACT(DESC, r"/(\d+)(?:[?#]|$)")

where the regex means

• / - a / char
• (\\d+) - Group 1 (the actual output): one or more digits
• (?:[?#]|$) - either ? or # char, or end of string.