Discover the REGEXP_EXTRACT_ALL Function in BigQuery for Pattern Extraction

The REGEXP_EXTRACT_ALL function in BigQuery is used to extract information from a string based on a specified regular expression pattern. It returns an array containing all occurrences in the string that match the pattern.

To use REGEXP_EXTRACT_ALL with a regex pattern in BigQuery, you should:

1. Identify the pattern you want to match within your string.
2. Test and refine your pattern using a regex debugger like regex101 to ensure it captures the desired information.
3. Apply the REGEXP_EXTRACT_ALL function in your query, passing the string and your regex pattern as arguments.

The limitation of the REGEXP_EXTRACT_ALL function in BigQuery is that it only works with a single regex capture group. This means you cannot use it to match multiple different patterns within the same string simultaneously.

Using regex101 or a similar regex debugger is recommended when working with REGEXP_EXTRACT_ALL because it allows you to:

• Test your regular expression patterns against representative examples.
• Debug and refine your patterns to ensure they accurately match the desired occurrences in your BigQuery strings.
• Avoid syntax errors and improve the efficiency of your regex patterns before applying them in your actual queries.