如何在 Google BigQuery 的字符串列中提取所有（包括 int 和 float）数值？

Question

I have a table Table_1 on Google BigQuery which includes a string column str_column . I would like to write a SQL query (compatible with Google BigQuery) to extract all numerical values in str_column and append them as new numerical columns to Table_1 . For example, if str_column includes first measurement is 22 and the other is 2.5 ; I need to extract 22 and 2.5 and save them under new columns numerical_val_1 and numerical_val_2 . The number of new numerical columns should ideally be equal to the maximum number of numerical values in str_column , but if that'd be too complex, extracting the first 2 numerical values in str_column (and therefore 2 new columns) would be fine too. Any ideas?

Answer 1

Consider below approach

select * from (
  select str_column, offset + 1 as offset, num
  from your_table, unnest(regexp_extract_all(str_column, r'\b([\d.]+)\b')) num with offset
)
pivot (min(num) as numerical_val for offset in (1,2,3))    

if applied to sample data like in your question - output is