trunc可以操作date,datetime,timestamp吗
oracle:
没有专门的DATETIME类型
完全支持以下类型:
DATE
TIMESTAMP
TIMESTAMP WITH TIME ZONE
TIMESTAMP WITH LOCAL TIME ZONE
示例:
sql
-- DATE类型
SELECT TRUNC(SYSDATE, 'HH24') FROM dual; -- 截断到小时
-- TIMESTAMP类型
SELECT TRUNC(SYSTIMESTAMP, 'DD') FROM dual; -- 截断到天
-- TIMESTAMP WITH TIME ZONE
SELECT TRUNC(SYSTIMESTAMP AT TIME ZONE 'UTC', 'MM') FROM dual;