oralce中日期的计算

Question

SQL> select trunc(sysdate-to_date('20030101','yyyymmdd')) from dual;TRUNC(SYSDATE-TO_DATE('20030101','YYYYMMDD'))
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                                           55实际：1091
SQL>

Answer 1

两个日期相减即可！select to_date('20010101','YYYYMMDD')-to_date('20000101','YYYYMMDD') from dual;

Answer 2

若带时间的，多加一函数trunc比较好:
select trunc(to_date('20010101','YYYYMMDD hh24:mi:ss')-to_date('20000101','YYYYMMDD hh24:mi:ss')) from dual;