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虽然SQL数据库是非常有用的工具，但经历了15年的一支独秀之后垄断即将被打破。这只是时间问题：被迫使用关系数据库，但最终发现不能适应需求的情况不胜枚举。
但是NoSQL数据库之间的不同，远超过两 SQL数据库之间的差别 ...
select colunmnid,connect_by_root(colunmnid) precolumnid
from Test
WHERE precolumnid IS NOT null
connect by prior colunmnid= precolumnid
order by 1,2
Create Table Test(colunmnid Integer,precolumnid Integer)
Insert Into Test Values(0,Null);
Insert Into Test Values(2,0);
Insert Into Test ...
(WITH t1 AS (select rtrim(user_id,',') str from dual)
SELECT s from (SELECT substr(t1.str,instr(t1.str,',',1,LEVEL) + 1,
decode(instr(t1.str,',',1, LEVEL + 1),0,length(str) + 1,
instr(t1.str,',',1,LEVEL + 1)) - instr(t1.str,',',1,LEVEL) - 1) s
FROM dual, t1 CONNECT BY LEVEL < ...
select max(decode(to_char(dt, 'day'), '星期日', to_char(dt, 'dd'))) "星期日",
max(decode(to_char(dt, 'day'), '星期一', to_char(dt, 'dd'))) "星期一",
max(decode(to_char(dt, 'day'), '星期二', to_char(dt, 'dd'))) "星期二",
max(decode(to_char(dt, 'day'), '星期三', to_c ...
select t.no,
case
when t.no >= 1 then
1 || '*' || t.no || '=' || 1 * t.no
else
''
end a,
case
when t.no >= 2 then
2 || '*' || t.no || '=' || 2 * t.no
else
''
end b,
cas ...
http://code.google.com/p/jquery-api-zh-cn/downloads/list
首先，以超级管理员的身份登录oracle
sqlplus sys/bjsxt as sysdba
然后，解除对scott用户的锁
alter user scott account unlock;
那么这个用户名就能使用了。
(默认全局数据库名orcl)
1、select ename, sal * 12 from emp; //计算年薪
2、select 2*3 from dual; //计算一个比较纯的数据用dual表
3、select sysdate from dual; //查看当前的系统时间
4、select ename, sal*12 anuual ...
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@taglib uri="http://jakarta.apache.org/struts/tags-html" prefix="html" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme() + " ...