Setting Big Query variables like mysql

Question

what is the bigquery equivalent to mysql variables like?

SET @fromdate = '2014-01-01 00:00:00',  -- dates for after 2013
@todate='2015-01-01 00:00:00',

@bfromdate = '2005-01-01 00:00:00', -- dates for before 2013
@btodate = '2005-01-01 00:00:00',

@achfromdate  = '2013-01-01 00:00:00', -- dates for ACH without submit time in 2013
@achtodate  = '2013-01-01 00:00:00',

@currency="USD";

Answer 1

You could use a WITH clause. It's not ideal, but it gets the job done.

-- Set your variables here
WITH vars AS (
  SELECT '2018-01-01' as from_date,
         '2018-05-01' as to_date
)

-- Then use them by pulling from vars with a SELECT clause
SELECT *
FROM   your_table 
WHERE  date_column BETWEEN
          CAST((SELECT from_date FROM vars) as date)
          AND
          CAST((SELECT to_date FROM vars) as date)

Or even less wordy:

#standardSQL
-- Set your variables here
WITH vars AS (
  SELECT DATE '2018-01-01' as from_date,
         DATE '2018-05-01' as to_date
)
-- Then use them by pulling from vars with a SELECT clause
SELECT *
FROM your_table, vars 
WHERE date_column BETWEEN from_date AND to_date