BigQuery减去两个表的计数？

Question

在MySQL中,我可以做到SELECT (SELECT COUNT(*) FROM table1) - (SELECT COUNT(*) FROM table2)两个表之间的计数差异.当我在BigQuery中尝试这个时,我得到:Subselect not allowed in SELECT clause.如何在BigQuery中运行这样的查询？

Answer 1

由于SELECT子句中不支持子选择,我将对此特定查询使用CROSS JOIN:

SELECT (SELECT COUNT(*) c FROM `publicdata.samples.natality`) 
  - (SELECT COUNT(*) c FROM `publicdata.samples.shakespeare`)