1、字符型轉成timestamp
select to_timestamp(loga006,'dd-MON-yyhh:mi:ss.ff AM') from loga_t;
2、timestamp轉成date型
select cast(to_timestamp(loga006,'dd-MON-yyhh:mi:ss.ff AM')as date) timestamp_to_date
loga_t
3、date型轉成timestamp
select cast(sysdateas timestamp) date_to_timestamp from loga_t
4、獲取timestamp格式的系統時間
select systimestamp from loga_t