Question

php 一个类调用另一个类的方法

<?php
require_once("conn/conn.php");
$db=new db("localhost","root","123456","blog");
$db->connec();
class Login{
public $name;
public $password;
function sql($name,$password){
$this->name=$name;
$this->password=$password;
$sql="select * from user where name='$name' and password='$password'";
$db->execute($sql);

}
}
?>
db是conn.php中的类里面有executed等方法，我想调用可是
出现一下提示：
Call to a member function execute() on a non-object in D:\AppServ\www\oopLogin\login.php on line 18
怎么改呀，

Answer 1

一种是将你的变量写成
global $db
第二种是，将$db=new db("localhost","root","123456","blog");
$db->connec();
放在你的类中。

Answer 2

$db调用了类以后的变量

可将
$db=new db("localhost","root","123456","blog");
$db->connec();

放在 function sql()方法里面

Answer 3

<?php
require_once("conn/conn.php");

class Login{
public $name;
public $password;
function sql($name,$password){
$db=new db("localhost","root","123456","blog");
$db->connec();
$this->name=$name;
$this->password=$password;
$sql="select * from user where name='$name' and password='$password'";
$db->execute($sql);

}
}
?>

Answer 4

$db->connec();
这句写错了。

应为:$db->connect();