我正在编写一个查询来搜索数据库并打印出结果客户编号。我一直在尝试添加错误检查，以便如果输入的数字不在数据库中，它会打印出一条消息。有没有什么方法可以让 php 第一次忽略输入字段，这样我就不必在加载网页后弹出消息？
<html>
<head>
<title>Select Customer Listing</title>
</head>
<?php
session_start();
echo "Hello, " .$_SESSION['username'];
//Address error handling
ini_set('display_errors', 1);
error_reporting(E_ALL & ~E_NOTICE);
//Define the Customer Number php variable name
$customer = $_POST['cusnum'];
print "<br>The customer number chosen is <strong>$customer</strong>.<br />";
//Attempt to connect
if($connection = @mysql_connect('localhost', 'username', 'password')){
print '<p>Successfully connected to MySQL.</p>';
}
else{
die('<p>Could not connect to MySQL because: <b>' .mysql_error().'</b></p>');
}
if(@mysql_select_db("GIULIANA_PREMIERE", $connection)){
print '<p>The <i>GIULIANA_PREMIERE</i> database has been selected.</p><hr>';
}
else{
die('<p>Could not select the GIULIANA_PREMIERE database because: <b.' .mysql_error().'</b></p>');
}
?>
<?php
//define query
$query = "SELECT * FROM CUSTOMER WHERE CUSTOMER_NUM = '$customer'";
$queryALL = "SELECT * FROM CUSTOMER";
$lower = strtolower($customer);
//output the resulting query table
if($r = mysql_query($query)){
while($row = mysql_fetch_array($r)){
print "<p><b>{$row['CUSTOMER_NUM']}</b> : {$row['CUSTOMER_NAME']}<BR/> </P>\n";
}
}
//if any case of 'all' is entered, print out query
if(strcmp($lower, 'all') == 0){
if($r2 = mysql_query($queryALL)){
while($row2 = mysql_fetch_array($r2)){
print "<p><b>{$row2['CUSTOMER_NUM']}</b> : {$row2['CUSTOMER_NAME']} <BR/></P>\n";
}
}
}
//if no number was entered, display pop up
if(empty($customer) && counter != 1){
print '<script language="javascript">';
print 'alert("Please enter a customer number.")';
print '</script>';
}
//if entered number was invalid, display message
if((mysql_num_rows($r) == 0) && (strcmp($lower, 'all') != 0)){
print "Not a valid cutomer number.";
print "<br>Please try again.";
}
?>
</body>
</html>
我已经尝试将所有 if 语句更改为 elseif 但我也无法让它工作。
最佳答案
试试这个:
<html>
<head>
<title>Select Customer Listing</title>
<script>
<?php
$counter = 0; //any number but one
if(empty($customer) && $counter != 1){
$counter = 1; //the condition has been met, lets change the variable to 1 so this condition isn't met again
?>
alert("Please enter a customer number.");
<?php
}
?>
</script>
</head>
//rest of your code
关于php - 忽略空提交的帖子？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/22047529/