Regexp_Extract BigQuery 直到“|”

Question

I'm fairly new to coding and I was wondering if you could give me a hand writing some regular expression for BigQuery SQL.

Basically I would like to extract everything before the bar sign "|"for one of my column.

Example:

• Source string: bla-BLABLA-cid=123456_sept1220_blabla--potato-Blah|someMore_string_stuff-IDontNeed

• Desired output: bla-BLABLA-cid=123456_sept1220_blabla--potato-Blah

I thought about using the REGEXP_EXTRACT(string, delimiter) function but I'm totally unable to write some regex (LOL). Therefore I had a look over Stack, and have found stuff like:

SELECT REGEXP_EXTRACT( String_Name , "\S*\s*\|" ) ,
# or 
SELECT REGEXP_EXTRACT( String_Name , '.+?(?=|)')

But every time I get error messages like " invalid perl operator: (?= " or "Illegal escape space"

Would you have any suggestions on why I get these messages and/or how could I proceed to extract these strings?

Many many thanks in advance <3

Answer 1

You can use SPLIT instead:

SELECT SPLIT("bla-BLABLA-cid=123456_sept1220_blabla--potato-Blah|someMore_string_stuff-IDontNeed", "|")[OFFSET(0)]

Answer 2

Prefix the pattern string with r :

SELECT REGEXP_EXTRACT(String_Name, r'\S*\s*\|')

This is the syntax for a raw string constant. You can review what this means in the documentation .