StandardSQL NTH() and FIRST() functions for BigQuery - sql

Question

I'm starting out in BigQuery, with some experience in pSQl.
The #legacySQL query I'm running successfully is:
SELECT
FIRST(SPLIT(ewTerms, '/')) AS place,
NTH(2, SPLIT(ewTerms, '/')) AS divisor
FROM (SELECT ewTerms FROM account.free)
The string values in the 'ewTerms' column from the table 'free' are single digit fractions, such as "2/4", "3/5", etc. This #legacySQl query successfully creates two columns from 'ewTerms', reading:
Row place divisor
1 3 5
2 2 4
I need now to use this column creation in a WITH function, so I have to switch to using #standardSQL.
Can anyone tell me how I can call to the string's FIRST() and NTH() functions using #standardSQL? I've tried:
WITH prep AS(
SELECT
SPLIT(ewTerms, '/') AS split
FROM (SELECT ewTerms FROM accounts.free)
)
SELECT
split[SAFE_ORDINAL(1)] AS place,
split[SAFE_ORDINAL(2)] AS divisor
FROM prep
but this is wrong. Help anyone?

Answer 1

Your question is not clear about what is wrong. This query works for me:
#standardSQL
WITH Input AS (
SELECT '3/5' AS ewTerms UNION ALL
SELECT '2/4' AS ewTerms
), prep AS (
SELECT
SPLIT(ewTerms, '/') AS split
FROM Input
)
SELECT
split[SAFE_ORDINAL(1)] AS place,
split[SAFE_ORDINAL(2)] AS divisor
FROM prep;
The output is:
+-------+---------+
| place | divisor |
+-------+---------+
| 2 | 4 |
| 3 | 5 |
+-------+---------+
Using your original table, your query would be:
#standardSQL
WITH prep AS (
SELECT
SPLIT(ewTerms, '/') AS split
FROM accounts.free
)
SELECT
split[SAFE_ORDINAL(1)] AS place,
split[SAFE_ORDINAL(2)] AS divisor
FROM prep;