需求说明：
需要查询出某个客户某一年那些天是有连续办理过业务
实现SQL如下：
创建表：
相关操作代码如下：

create table test_num
(tyear number,
tdate date);

测试数据：
insert into test_num
select 2014,trunc(sysdate)-1 from dual union all
select 2014,trunc(sysdate)-002 from dual union all
select 2014,trunc(sysdate)-003 from dual union all
select 2014,trunc(sysdate)-004 from dual union all
select 2014,trunc(sysdate)-005 from dual union all
select 2014,trunc(sysdate)-007 from dual union all
select 2014,trunc(sysdate)-008 from dual union all
select 2014,trunc(sysdate)-009 from dual union all
select 2013,trunc(sysdate)-120 from dual union all
select 2013,trunc(sysdate)-121 from dual union all
select 2013,trunc(sysdate)-122 from dual union all
select 2013,trunc(sysdate)-124 from dual union all
select 2013,trunc(sysdate)-125 from dual union all
select 2013,trunc(sysdate)-127 from dual union all
select 2015,trunc(sysdate)-099 from dual union all
select 2015,trunc(sysdate)-100 from dual union all
select 2015,trunc(sysdate)-101 from dual union all
select 2015,trunc(sysdate)-102 from dual union all
select 2015,trunc(sysdate)-104 from dual union all
select 2015,trunc(sysdate)-105 from dual;
写SQL:
相关操作代码如下：

SELECT TYEAR, MIN(TDATE) AS STARTDATE, MAX(TDATE), COUNT(TYEAR) AS ENDNUM
FROM (SELECT A.*, A.TDATE - ROWNUM AS GNUM
FROM (SELECT * FROM TEST_NUM ORDER BY TYEAR, TDATE) A)
GROUP BY TYEAR, GNUM
ORDER BY TYEAR, MIN(TDATE)

oracle的归档模式 ORACLE数据库归档日志常用命令

Oracle数据库有联机重做日志，这个日志是记录对数据库所做的修改，比如插入，删除，更新数据等，对这些操作都会记录在联机重做日志里

数据库,归档日志,归档