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1. 使用SERVER MANAGER关闭实例.
SVRMGR > connect internal;
SVRMGR > shutdown;
SVRMGR >exit;
2. 使用操作系统命令来移动数据库文件位置(假设这里操作系统为SOLARIS 2.6). 在UNIX中用 mv命令可以把文件移动到新的位置，
#mv /ora13/orarun/document.dbf /ora12/orarun
3. 装载数据库并用alter database命令来改变数据库中的文件名.
SVRMGR > connect internal;
SVRMGR > startup mount RUN73;
SVRMGR > alter database rename file
> ‘/ ora13/orarun/document.dbf’
> ‘/ ora12/orarun/document.dbf’;
4. 启动实例.
SVRMGR > alter database open;
15．连接查询结果：
表a 列 a1 a2
记录 1 a
1 b
2 x
2 y
2 z
用select能选成以下结果:
1 ab
2 xyz
下面有两个例子：
1.使用pl/sql代码实现，但要求你组合后的长度不能超出oracle varchar2长度的限制
create or replace type strings_table is table of varchar2(20);
/
create or replace function merge (pv in strings_table) return varchar2
is
ls varchar2(4000);
begin
for i in 1..pv.count loop
ls := ls || pv(i);
end loop;
return ls;
end;
/
create table t (id number,name varchar2(10));
insert into t values(1,''''Joan'''');
insert into t values(1,''''Jack'''');
insert into t values(1,''''Tom'''');
insert into t values(2,''''Rose'''');
insert into t values(2,''''Jenny'''');
column names format a80;
select t0.id,merge(cast(multiset(select name from t where t.id = t0.id) as strings_table)) names
from (select distinct id from t) t0;
drop type strings_table;
drop function merge;
drop table t;
2.纯粹用sql：
表dept, emp
要得到如下结果
deptno, dname, employees
---------------------------------
10, accounting, clark;king;miller
20, research, smith;adams;ford;scott;jones
30, sales, allen;blake;martin;james;turners
每个dept的employee串起来作为一条记录返回
This example uses a max of 6, and would need more cut n pasting to do more than that：
SQL> select deptno, dname, emps
2 from (
3 select d.deptno, d.dname, rtrim(e.ename ||'''', ''''||
4 lead(e.ename,1) over (partition by d.deptno
5 order by e.ename) ||'''', ''''||
6 lead(e.ename,2) over (partition by d.deptno
7 order by e.ename) ||'''', ''''||
8 lead(e.ename,3) over (partition by d.deptno
9 order by e.ename) ||'''', ''''||
10 lead(e.ename,4) over (partition by d.deptno
11 order by e.ename) ||'''', ''''||
12 lead(e.ename,5) over (partition by d.deptno
13 order by e.ename),'''', '''') emps,
14 row_number () over (partition by d.deptno
15 order by e.ename) x
16 from emp e, dept d
17 where d.deptno = e.deptno
18 )
19 where x = 1
20 /
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