oracle查关时间操作
Oracle关于时间/日期的操作
1.日期时间间隔操作
当前时间减去7分钟的时间
Java代码
select sysdate,sysdate - interval '7' MINUTE from dual
select sysdate,sysdate - interval '7' MINUTE from dual
当前时间减去7小时的时间
Java代码
select sysdate - interval '7' hour from dual
select sysdate - interval '7' hour from dual
当前时间减去7天的时间
Java代码
select sysdate - interval '7' day from dual
select sysdate - interval '7' day from dual
当前时间减去7月的时间
Java代码
select sysdate,sysdate - interval '7' month from dual
select sysdate,sysdate - interval '7' month from dual
当前时间减去7年的时间
Java代码
select sysdate,sysdate - interval '7' year from dual
select sysdate,sysdate - interval '7' year from dual
时间间隔乘以一个数字
Java代码
select sysdate,sysdate - 8 *interval '2' hour from dual
select sysdate,sysdate - 8 *interval '2' hour from dual
2.日期到字符操作
Java代码
select sysdate,to_char(sysdate,'yyyy-mm-dd hh24:mi:ss') from dual
select sysdate,to_char(sysdate,'yyyy-mm-dd hh:mi:ss') from dual
select sysdate,to_char(sysdate,'yyyy-ddd hh:mi:ss') from dual
select sysdate,to_char(sysdate,'yyyy-mm iw-d hh:mi:ss') from dual
select sysdate,to_char(sysdate,'yyyy-mm-dd hh24:mi:ss') from dual
select sysdate,to_char(sysdate,'yyyy-mm-dd hh:mi:ss') from dual
select sysdate,to_char(sysdate,'yyyy-ddd hh:mi:ss') from dual
select sysdate,to_char(sysdate,'yyyy-mm iw-d hh:mi:ss') from dual
参考oracle的相关关文档(ORACLE901DOC/SERVER.901/A90125/SQL_ELEMENTS4.HTM#48515)
3. 字符到日期操作
Java代码
select to_date('2003-10-17 21:15:37','yyyy-mm-dd hh24:mi:ss') from dual
select to_date('2003-10-17 21:15:37','yyyy-mm-dd hh24:mi:ss') from dual
具体用法和上面的to_char差不多。
4. trunk/ ROUND函数的
相关文档：
推荐crs版本高于db版本
If you also plan to apply this patch to Oracle Clusterware,
ensure that you apply the patch to Oracle Clusterware before
applying it to Oracle Database. This is because Oracle Clusterware
hould always be at the same or later version as the database.
涉及到数据库而不是实例� ......
1.oracle环境
create table test
(
id number(4),
name varchar2(20)
)
在一个session中
insert into test values(1,'aa');
在另一个session中
select * from test1;
查询没被阻塞
2.sqlserver环境
在一个session中
insert into test values(1,'aa');
在另一个session中
select * from test1;
查询被阻塞(� ......
一、安装(略)
服务器端
1、windows:（略）
2、linux:待续...
客户端
待续...
--包括配置--
二、登陆
......
先看一段ORACLE官方文档
http://download-west.oracle.com/docs/cd/B10501_01/server.920/a96520/analysis.htm#25806:
FIRST/LAST Functions
The FIRST/LAST aggregate functions allow you to return the result of an aggregate applied over a set of rows that rank as the first or last with respect to a ......
oracle cast() 函数问题
SQL> create table t1(a varchar(10));
Table created.
SQL> insert into t1 values ('12.3456');
1 row created.
SQL> select round(a) from t1;
ROUND(A)
----------
12
SQL> select round(a,3) from t1;
ROUND(A,3)
- ......
