BigQuery add new columns into nested STRUCT in subquery

问题

I have the following table that contains nested STRUCTs, and in a subquery, I am trying to add additional columns at the struct level. I've created a reproducible example of my efforts thus far:

WITH wide_stats AS (
  (
    SELECT 
      'joe' name, 'bills' team,
      struct(struct(7 as fga, 5 as fgm) as o, struct(8 as fga, 3 as fgm) as d) as t1,
      struct(struct(3 as fga, 4 as fgm) as o, struct(9 as fga, 2 as fgm) as d) as t2
  ) UNION ALL (
    SELECT 'nick' name, 'jets' team,
      struct(struct(12 as fga, 7 as fgm) as o, struct(13 as fga, 7 as fgm) as d) as t1,
      struct(struct(15 as fga, 7 as fgm) as o, struct(22 as fga, 7 as fgm) as d) as t2
  )
)

SELECT 
  *,
--   safe_divide(wide_stats.t1.o.fgm, wide_stats.t1.o.fga) as fg_pct,
  safe_divide(wide_stats.t1.o.fgm, wide_stats.t1.o.fga) as wide_stats.t1.o.fg_pct  

FROM wide_stats

The current code throws an error Syntax error: Unexpected "." at [18:70] at line 18 (with the safe_divide). If I switch in line 17 / out line 18, the code works, but then fg_pct is not in the t1.o struct, where i'd like it to be.

Is there any way to add columns into nested structs in subqueries like this?

回答1:

Below is for BigQuery Standard SQL

#standardSQL
WITH wide_stats AS (
  SELECT 'joe' name, 'bills' team,
    STRUCT(STRUCT(7 AS fga, 5 AS fgm) AS o, STRUCT(8 AS fga, 3 AS fgm) AS d) AS t1,
    STRUCT(STRUCT(3 AS fga, 4 AS fgm) AS o, STRUCT(9 AS fga, 2 AS fgm) AS d) AS t2 UNION ALL 
  SELECT 'nick' name, 'jets' team,
    STRUCT(STRUCT(12 AS fga, 7 AS fgm) AS o, STRUCT(13 AS fga, 7 AS fgm) AS d) AS t1,
    STRUCT(STRUCT(15 AS fga, 7 AS fgm) AS o, STRUCT(22 AS fga, 7 AS fgm) AS d) AS t2
)
SELECT * REPLACE (
  (SELECT AS STRUCT t1.* REPLACE (
    (SELECT AS STRUCT t1.o.*, SAFE_DIVIDE(wide_stats.t1.o.fgm, wide_stats.t1.o.fga) AS fg_pct ) 
    AS o))
  AS t1)
FROM wide_stats

with result

Row name    team    t1.o.fga    t1.o.fgm    t1.o.fg_pct         t1.d.fga    t1.d.fgm    t2.o.fga    t2.o.fgm    t2.d.fga    t2.d.fgm     
1   joe     bills   7           5           0.7142857142857143  8           3           3           4           9           2    
2   nick    jets    12          7           0.5833333333333334  13          7           15          7           22          7

来源：https://stackoverflow.com/questions/58785627/bigquery-add-new-columns-into-nested-struct-in-subquery

标签

google-bigquery