在 DATE 类型上透视 BigQuery 表

Question

I'm trying to pivot a table with each row being a transaction with a date. Eg

WITH Produce AS (
  SELECT 'Kale' as product, 51 as sales, DATE('2020-01-01') as dates UNION ALL
  SELECT 'Kale', 23, DATE('2020-01-02') UNION ALL
  SELECT 'Kale', 45, DATE('2020-01-03') UNION ALL
  SELECT 'Kale', 3,  DATE('2020-01-04') UNION ALL
  SELECT 'Apple', 70, DATE('2020-01-01') UNION ALL
  SELECT 'Apple', 85, DATE('2020-01-02') UNION ALL
  SELECT 'Apple', 77, DATE('2020-01-03') UNION ALL
  SELECT 'Apple', 1, DATE('2020-01-04')
)

My query is something like this.

SELECT * FROM Produce
PIVOT(sum(sales) FOR dates IN (DATE('2020-01-01'), DATE('2020-01-02'), DATE('2020-01-03'), DATE('2020-01-04')))

However BigQuery returns the following error.

Generating an implicit alias for this PIVOT value is not supported; please provide an explicit alias at [14:41]

According to the docs , pivot columns with type of date should be able to generate alias implicitly, or is my understanding wrong?

Answer 1

Use below instead

SELECT * FROM Produce
PIVOT(sum(sales) FOR dates IN ('2020-01-01','2020-01-02', '2020-01-03', '2020-01-04'))          

with output

Answer 2

From Rules for pivot_column:

A pivot_column must be a constant.

DATE('2020-01-01') is an expression, not a constant. So you need to use one of followings.

PIVOT(sum(sales) FOR dates IN (DATE '2020-01-01', ...) -- explicit DATE literal
-- or
PIVOT(sum(sales) FOR dates IN ('2020-01-01', ...) -- literal implicitly coerced to DATE type
-- or
PIVOT(sum(sales) FOR dates IN (DATE('2020-01-01') AS _2020_01_01, ...) -- alias