3、处理时间戳和间隔类型:除了日期值,Oracle还支持时间戳和间隔类型,对于时间戳和间隔类型,你需要先将它们转换为日期值,然后再使用ADD_HOURS函数进行操作。 如果你有一个时间戳TIMESTAMP '20230704 15:30:00',并且想要将其减少一个小时,可以使用以下代码: “`sql SELECT TO_DATE(TO_CHAR(TIMESTAMP ‘
从dual 中选择 to_char(sysdate,'yyyy-mm-dd hh24:mi:ss') 作为 nowTime;// 日期返回为字符串 selectto_char(sysdate,'yyyy')asnowYearfromdual;//获取时间的年selectto_char(sysdate,'mm')asnowMonthfromdual;//获取时间的月selectto_char(sysdate,'dd')asnowDayfromdual;//获取时间的日期selectto_cha...
5、current_date、current_timestamp、localtimestamp、sessiontimezone、dbtimezone函数 current_date:9i新增函数,返回当前会话时区所对应的日期时间(date型) current_timestamp:以 timestamp with time zone 数据类型返回当前会话时区所对应的日期时间。 localtimestamp:返回当前会话时区的日期时间 sessiontimezone:返回会...
SQL> select sessiontimezone,current_date from dual; SESSIONTIMEZONE CURRENT_DA --- --- +08:00 13-11月-03 SQL> alter session set time_zone='-11:00' 2 / 会话已更改。 SQL> select sessiontimezone,current_timestamp from dual; SESSIONTIMEZONE CURRENT_TIMESTAMP --- --- -11:00 12-11...
获得小时数 extract()找出日期或间隔值的字段值 SELECT EXTRACT(HOUR FROM TIMESTAMP '2001-02-16 2:38:40') from offer SQL> select sysdate ,to_char(sysdate,'hh') from dual; SYSDATE TO_CHAR(SYSDATE,'HH') --- --- 2003-10-13 19:35:21 07 SQL> select sysdate ,to_char(sysdate,'hh24'...
2、TIMESTAMP - 存储日期、时间和时区信息,秒值精确到小数点后6位 语法 Select systimestamp from dual; 1. 插入日期型数据(to_date的用法) INSERT INTO FLOOR VALUES ( to_date ( '2007-12-20 18:31:34' , 'YYYY-MM-DD HH24:MI:SS' ) ) ; ...
TIMESTAMP WITH LOCAL TIME ZONE —与 TIMESTAMP WITH TIME ZONE 相对,此类型的值中不包含时区偏移量,而是由用户的当地会话时区确定该值。 日期时间由许多字段组成,其数量由数据类型的粒度和变体决定。可以使用 EXTRACT 语句通过 SQL 查询将这些字段提取出来。要了解有关数据类型中的可用字段和时间间隔的详细信息,请...
Table 14-106 OracleTimeStamp Methods MethodsDescription AddDays Adds the supplied number of days to the current instance AddHours Adds the supplied number of hours to the current instance AddMilliseconds Adds the supplied number of milliseconds to the current instance AddMinutes Adds the supplied number...
As you learned previously, you can administer the Exadata Database Machine in several ways: using the command-line tool CellCLI (or a number of cells at the same time by DCLI), using SRVCTL and CRSCTL, and via plain-old SQL commands. But the easiest approach, hands down, is to use O...
next_day, regexp_instr, add_months, systimestamp, to_number, empty_clob and empty_blob. To use these functions as default values, ensure that the destination database has the same functions. If the destination database does not have the corresponding function, the following results may be ...