如何用PHP跨数据库导入数据

Question

比如我有两个数据库A，B 
数据库B下有个表b插到数据库A下的表a 
表b结构为 
CREATE TABLE IF NOT EXISTS `b` ( 
  `cid` int(11) NOT NULL auto_increment, 
  `username` varchar(25) NOT NULL, 
  `Upassword` varchar(255) NOT NULL, 
  `area` varchar(25) NOT NULL, 
  `cost` int(255) NOT NULL, 
  PRIMARY KEY  (`cid`) 
) 
如何用PHP实现下面这句 
$sql="insert into a(cid,username,Upassword,area) 
      select t1.cid,t1.username,t1.Upassword,t1.area from B.b t1"; 下面是我自己写的一段PHP
<?php 
$host="localhost"; 
$user="root"; 
$password="123456"; 
$database_1="a"; 
$database_2="b"; session_start(); $link=mysql_connect($host,$user,$password) or die("fail"); 
mysql_select_db($database_2,$link); 
$sql="select cid,username,Upassword,area from b"; 
$result=mysql_query($sql); 
while (list($cid->cid,$username->username,$Upassword->Upassword,$area->area)=mysql_fetch_array($result)){ 
echo $cid->cid.' '.$username->username.' '.$Upassword->Upassword.' '.$area->area.' <br>'; 
    } 
$link_2=mysql_connect($host,$user,$password) or die("fail"); 
mysql_select_db($database_1,$link_2); 
$sql="insert into a(cid,username,Upassword,area) 
        values('$row_user->cid','$row_user->username','$row_upa->Upassword','$row_area->area');"; mysql_query($sql); 
mysql_close($link); //关闭数据库连接 
echo "Hello!successful!"; //显示提示信息 
?> 我刷新一次，a的cid就自动增长一次，其它都为空，为什么是这样，那个地方要改

Answer 1

$sql="insert into a(cid,username,Upassword,area) 
    values('$row_user->cid','$row_user->username','$row_upa->Upassword','$row_area->area');"; echo $sql看一下你的这个$sql 的内容到底是什么？

Answer 2

我是想把上面取出来的弄成数组，然后插到这个表上去，values('$row_user->cid','$row_user->username','$row_upa->Upassword','$row_area->area');";这句要怎改，

Answer 3

我自己搞定了，哈哈<?php
$host="localhost";
$user="root";
$password="123456";
$database_1="a";
$database_2="b";session_start();$link=mysql_connect($host,$user,$password) or die("fail");
mysql_select_db($database_2,$link);
$sql_1="select cid,username,Upassword,area from b";
$result_cid=mysql_query($sql_1);while(list($cid['cid'],$username['username'],$Upassword['Upassword'],$area['area'])=mysql_fetch_array($result_cid)){
echo $cid['cid'].' '.$username['username'].' '.$Upassword['Upassword'].' '.$area['area'].'<br>';
$row_cid=$cid['cid'];
$row_user=$username['username'];
$row_upa=$Upassword['Upassword'];
$row_area=$area['area'];
mysql_select_db($database_1,$link);
$sql_2="insert into b(cid,username,Upassword,area)
       values('$row_cid','$row_user','$row_upa','$row_area')";
mysql_query($sql_2);

}
?>