使用php简单删除查询

Question

I am trying to create a delete query from HTML using PHP:

HTML:

<form method="POST" action="" >
    ID<input type="text" name="x" />
    <input type="submit"  value="DELETE" name="del"/>
</form>

PHP:

<?php
$connection = mysql_connect("localhost","root","") or die ("Couldn't connect to server");
$db = mysql_select_db("smap", $connection) or die ("Couldn't select database");
if(isset($_POST['del'])) {
    $a = $_POST['x'];
    $sql = mysql_query("DELETE syracuseone WHERE ID ='$a'";)
    if(mysql_query($sql)) {
        echo "deleted";
    } else {
        echo "fail";
    } 
}
?>

I get this error:

Notice: Undefined index: x

Any assistance from stack?

Answer 1

It means that your post value was not passed to the next page, you can do something like this $a = isset($_POST['x']) ? $_POST["a"] : 0;

Take a look, here is it's usage:

<form method="POST" action="" >
    ID<input type="text" name="x" />
    <input type="submit"  value="DELETE" name="del"/>
</form>

<?php
$connection = mysql_connect("localhost", "root", "") or die("Couldn't connect to server");
$db         = mysql_select_db("smap", $connection) or die("Couldn't select database");
if(isset($_POST['del'])){
    $a   = isset($_POST['x']) ? $_POST["a"] : 0;
    $sql = mysql_query("DELETE FROM syracuseone WHERE ID ='$a'");
    if(mysql_query($sql)){
        echo "deleted";
    }else{
        echo "fail";
    }
}
?>