PLSQL 计算两个日期之间的天数

SELECT count(1) - 1 days
FROM (
select distinct trunc(to_date(‘2019-03-01’,‘yyyy-mm-dd’)) + level - 1 daylist
from dual
connect by trunc(to_date(‘2019-03-01’,‘yyyy-mm-dd’))+ level - 1 <= trunc(to_date(‘2019-03-06’,‘yyyy-mm-dd’))
)