最近做一个项目,说起来比较恶,是从另一个表中读取数据送到这个表中.而且要用触发器循环这些内容再发出去.
可是如果这个数据量很大的话,会一下子挂死.所以就想到了.能不能,每次我传一点,隔几秒再送一点.
下面是一个简单的例子
declare @i int
set @i=1
while @i<101
begin
insert into Cname ([name],csex,Number) values('aaaaaa','1',@i)
set @i=@i+1
if @i%10=0
    waitfor DELAY '000:00:30'
end
这里用到了waitfor DELAY ......

Last login: Mon Feb  8 14:13:19 2010 from 192.168.1.249
ipnet
-bash-3.00$
-bash-3.00$ ipnet
-bash: ipnet: command not found
-bash-3.00$ su - oracle
Password:
eastcsu: incorrect password
-bash-3.00$ eastcom
-bash: eastcom: command not found
-bash-3.00$ su - oracle
Password:
[oracle@ipnet-td2 ~]$
[oracle@ipnet-td2 ~]$ sqlplus /nolog
SQL*Plus: Release 10.2.0.1.0 - Production on Mon Feb 8 14:14:08 2010
Copyright (c) 1982, 2005, Oracle.  All rights reserved.
SQL> su^H^H^H
SP2-0042: unknown command " - rest of line ignored.
SQL> conn ipnet/ipnet1234@ORAC^H^H^H
ERROR:
ORA-12154: TNS:could not resolve the connect identifier specified
SQL> ^[[A^H               " - rest of line ignored.
SQL> 042: unknown command "
SQL> conn ipnet/ipnet1234@ORCL
Connected.
SQL> set timn^H
SP2-0158: unknown SET option "tim"
SQL> set timing on
SQL> set autot traceonly
SQL> sel ......

Last login: Mon Feb  8 14:13:19 2010 from 192.168.1.249
ipnet
-bash-3.00$
-bash-3.00$ ipnet
-bash: ipnet: command not found
-bash-3.00$ su - oracle
Password:
eastcsu: incorrect password
-bash-3.00$ eastcom
-bash: eastcom: command not found
-bash-3.00$ su - oracle
Password:
[oracle@ipnet-td2 ~]$
[oracle@ipnet-td2 ~]$ sqlplus /nolog
SQL*Plus: Release 10.2.0.1.0 - Production on Mon Feb 8 14:14:08 2010
Copyright (c) 1982, 2005, Oracle.  All rights reserved.
SQL> su^H^H^H
SP2-0042: unknown command " - rest of line ignored.
SQL> conn ipnet/ipnet1234@ORAC^H^H^H
ERROR:
ORA-12154: TNS:could not resolve the connect identifier specified
SQL> ^[[A^H               " - rest of line ignored.
SQL> 042: unknown command "
SQL> conn ipnet/ipnet1234@ORCL
Connected.
SQL> set timn^H
SP2-0158: unknown SET option "tim"
SQL> set timing on
SQL> set autot traceonly
SQL> sel ......

具体实现如下：
SQL> select count(*) from v$session  #连接数
SQL> Select count(*) from v$session where status='ACTIVE'　#并发连接数
SQL> show parameter processes  #最大连接
SQL> alter system set processes = value scope = spfile;重启数据库  #修改连接 ......

具体实现如下：
SQL> select count(*) from v$session  #连接数
SQL> Select count(*) from v$session where status='ACTIVE'　#并发连接数
SQL> show parameter processes  #最大连接
SQL> alter system set processes = value scope = spfile;重启数据库  #修改连接 ......

SQL常用分页的办法:
表中主键必须为标识列，[ID] int IDENTITY (1,1)
1.分页方案一：(利用Not In和SELECT TOP分页)
语句形式： 
SELECT TOP 页记录数量 *
from 表名
WHERE (ID NOT IN
  (SELECT TOP (每页行数*(页数-1)) ID
  from 表名
  ORDER BY ID))
  ORDER BY ID
//自己还可以加上一些查询条件
例:
select top 2 *
from Sys_Material_Type
where (MT_ID not in
    (select top (2*(3-1)) MT_ID from Sys_Material_Type  order by MT_ID))
order by MT_ID
2.分页方案二：(利用ID大于多少和SELECT TOP分页）
语句形式：
SELECT TOP 每页记录数量 *
from 表名
WHERE (ID >
          (SELECT MAX(id)
    from (SELECT TOP 每页行数*页数 id  from 表
          ORDER BY id) AS T)
      )
ORDER BY ID
例:
SELECT TOP 2 *
from Sys_Material_Type
WHERE (MT_ID >
          (SELECT MAX(MT_ID)
          from ......

1、在数据库建表的时候字段直接设置为DATETIME类型；
2、执行插入的时候使用如下语句：
PreparedStatement pstmt = conn.prepareStatement("insert into guestbook(gst_user,gst_title,gst_content,gst_ip,gst_time) values(?,?,?,?,getdate())");
3、要把日期从数据库中取出，执行如下语句：
     Timestamp ts = rs.getTimestamp("gst_time");
     long lms = ts.getTime();
     Date date = new Date(lms);
     Time time = new Time(lms);
最终就可以直接使用date和time了。
out.println("留言时间：" + date + " " + time); ......

1、在数据库建表的时候字段直接设置为DATETIME类型；
2、执行插入的时候使用如下语句：
PreparedStatement pstmt = conn.prepareStatement("insert into guestbook(gst_user,gst_title,gst_content,gst_ip,gst_time) values(?,?,?,?,getdate())");
3、要把日期从数据库中取出，执行如下语句：
     Timestamp ts = rs.getTimestamp("gst_time");
     long lms = ts.getTime();
     Date date = new Date(lms);
     Time time = new Time(lms);
最终就可以直接使用date和time了。
out.println("留言时间：" + date + " " + time); ......

MS SQL Server2000 数据源配置
（注：sqljdbc.jar下载不到的话，找我索取pengqinghui110@126.com)
1、在项目的WebRoot下的META-INF中新建context.xml文件。内容如下：
<?xml version="1.0" encoding="UTF-8"?>
<Context>
    <Resource name="jdbc/sqlserver"
       auth="Container"
       type="javax.sql.DataSource"
       driverClassName="com.microsoft.sqlserver.jdbc.SQLServerDriver"
       url="jdbc:sqlserver://localhost:1433"
       username="sa"
       password="123456"
       maxActive="20"
       maxIdle="10"
       maxWait="-1" />
</Context>
2、往项目下的web.xml中新增如下代码：
<resource-ref>
    <res-ref-name>jdbc/sqlserver</res-ref-name>
  ......