How to extract all (including int and float) numerical values in a string column in Google BigQuery?-CodePudding

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?

CodePudding user response：

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