仅使用子选择的Oracle查询

Question

我只想返回有三列的1行

(SELECT count(1) from tests) TestCount, 
(select count(1) from customers) CustomerCount, 
(select count(1) from patients) PatientCount

Answer 1

请试试:

select 
  (SELECT count(1) from tests) TestCount, 
  (select count(1) from customers) CustomerCount, 
  (select count(1) from patients) PatientCount
from dual;