Question

<?php
include 'connect.php';
$conn = mysqli_connect($host, $user, $pass, $db);

if (!$conn) {
    die("KO" . mysqli_connect_error());
}

$id = $_GET['id'];

$sql = "select * from tblabc where id = '$id'";

if (mysqli_num_rows($sql)==0){
    echo 'ok';
} else {
    $data = mysqli_fetch_assoc($sql);
}
?>

这是我编辑表记录的代码。但是当它执行时发生错误“notice：Undefined index：id”。如何解决这个问题。 THX

Answer 1

import simpy

class Machine:
    def __init__(self,env):
        self.machine = simpy.Resource(env,capacity=1)
        self.load_proc = env.process(self.load(env))

    def load(self,env):
        "Load machine 1 when it's empty"
        while True:
            print("Waiting for machine at %d" %env.now)
            req = self.machine.request()
            yield req
            print("Load machine at %d" %env.now)
            self.process_proc = env.process(self.process(env,req))

    def process(self,env,req):
        "Machine does process and is then emptied"
        print("Machine starts process at %d" %env.now)
        yield env.timeout(10)
        print("Machine finished process at %d" %env.now)
        self.machine.release(req)
        print("Machine released at %d" %env.now)

env = simpy.Environment()
M1 = Machine(env)
env.run(until=100)

使用上面的代码在使用之前检查get变量的有效性。这样你就可以知道错误的来源。

Answer 2

你应该试试这个

$id  = '';
if(isset($_GET['id']) && $_GET['id'] != '')
{
    $id = $_GET['id']; 
    $sql = "select * from tblabc where id = '$id'";

    if (mysqli_num_rows($sql)==0){
        echo 'ok';
    } else {
        $data = mysqli_fetch_assoc($sql);
    }
}
else
{
echo 'Id Not Defined';
}

未定义的php $ id索引获取变量的值

2 个答案: