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\',
You may want to consider looking into BigQuery's Parameterized Queries. BigQuery supports query parameters to help prevent SQL injection when queries are constructed using user input. This feature is only available with standard SQL syntax.
https://cloud.google.com/bigquery/docs/parameterized-queries