为什么 BigQuery 不允许我的正则表达式在 Postgres 中运行？

Question

I'm running the following query against a Postgres DB:

SUBSTRING(my_col, '[0-9\-]+') AS extracted_string

Which works fine and extracts the sequence I want, but when I run the equivalent BigQuery query:

REGEXP_EXTRACT(my_col, '[0-9\-]+') AS extracted_string

It throws an exception saying:

Syntax error: Illegal escape sequence: \\-

Answer 1

You have to specify that your regex strings are in fact regex strings and should be treated differently in BigQuery.

The fix is to place the r character in front of your regex string like so:

REGEXP_EXTRACT(my_col, r'[0-9\-]+') AS extracted_string