drop table test_olap;
-- Create table
create table TEST_OLAP
(
CLASS NUMBER(1),
NAME VARCHAR2(100),
SCORE NUMBER(4,1) default 0
);
delete from test_olap;
insert into test_olap (class, name,score)values(2, 'b2', 34);
insert into test_olap (class, name,score)values(3, 'b3', 34);
commit;
select t.class, t.name, t.score
from test_olap t
where t.class > 1
order by t.score;
查询结果:
class name score
3 b3 34.0 --后插入的结果排在前面
2 b2 34.0
接下来:
delete from test_olap;
insert into test_olap (class, name, score) values (3, 'b3', 34);
insert into test_olap (class, name, score) values (2, 'b2', 34);
commit;
select t.class, t.name, t.score
from test_olap t
where t.class > 1
order by t.score;
查询结果:
class name score
2 b2 34.0 --后插入的结果排在前面
3 b3 34.0
为什么在排序的时候,后插入数据库的记录会排在前面呢?
1楼说的对，但相同的值，你可以按照rowid来排。一般后插入的值rowid那个串会比前面的大。
ORACLE默认是不保证任何排序的
显示出来结果的顺序就是读取数据的顺序
虽然你这里加了ORDER BY
可是由于两条记录的SCORE的值是相同的
所以ORDER B
exp user/password@dbname file=c:\table.dmp tables=jbitaku,jbitakum grants=y
然後按回車鍵 說明: user/password@dbname 分別表示用戶名，密碼和服務名 f ......
private static final String URL = "jdbc:oracle:thin:@localhost:1521:orcl";
private static final String USERNAME = "sys";
private static final String PASSWORD = "s ......
