SPLIT_PART() entire column in redshift

Question

How do I split_part an entire column(word-by-word)? I am trying to split the column "answer" into each word.

eg this is my dataset:

name	answer
Kate	i love cheese
Tom	i love bacon & eggs

this is what i want:

name	split_answer
Kate	i
Kate	love
Kate	cheese
Tom	i
Tom	love
Tom	bacon
Tom	&
Tom	eggs

this is my query:

SELECT name, split_part(answer, ' ') AS split_asnwer FROM table

Answer 1

Split_part() can take 3 arguments - string, delimiter, and part number.

So you need to cross join with a numbers table that has all the integer values from 1 to the max number of parts in any string. You can generate this numbers table with a recursive CTE or some like to just have a numbers table on hand.

The query will look something like (untested and off the cuff):

with recursive nums(n) as (
  select 1 as n
  union all
  select n + 1 
  from nums 
  where n < (select max(LEN(answer) - LEN(REPLACE(answer, ' ', '')) + 1) from table)
)
select name, split_part(answer, ' ', n) AS split_answer 
FROM table
cross join nums
where split_answer <> '';