我的代码中有这 3 个错误。我该如何修复它们？
警告：mysqli_query() 期望参数 1 为 mysqli，整数在 D:\hosting....\html\template_signupfunctions.php 第 14 行给出
警告：mysqli_num_rows() 期望参数 1 为 mysqli_result，在第 15 行给出的 inD:\hosting....\html\template_signupfunctions.php 为空
警告：mysqli_num_rows() 期望参数 1 为 mysqli_result，布尔值在 D:\hosting....\html\template_signupfunctions.php 第 48 行给出
警告：mysqli_num_rows() 期望参数 1 为 mysqli_result，布尔值在 D:\hosting....\html\template_signupfunctions.php 第 52 行给出
这是我的代码。
session_start();
// If user is logged in, header them away
if(isset($_SESSION["username"])){
header("location: message.php?msg=NO to that weenis");
exit();
}
// Ajax calls this NAME CHECK code to execute
if(isset($_POST["usernamecheck"])){
$db_conx = include_once("php_includes/db_connect.php");
$username = preg_replace('#[^a-z0-9]#i', '', $_POST['usernamecheck']);
$sql = "SELECT id FROM users WHERE username='$username' LIMIT 1";
$query = mysqli_query($db_conx, $sql);
$uname_check = mysqli_num_rows($query) ;
if (strlen($username) < 3 || strlen($username) > 16) {
echo '<strong style="color:#F00;">3 - 16 characters please</strong>';
exit();
}
if (is_numeric($username[0])) {
echo '<strong style="color:#F00;">Usernames must begin with a letter</strong>';
exit();
}
if ($uname_check < 1) {
echo '<strong style="color:#009900;">' . $username . ' is OK</strong>';
exit();
} else {
echo '<strong style="color:#F00;">' . $username . ' is taken</strong>';
exit();
}
}
// Ajax calls this REGISTRATION code to execute
if(isset($_POST["u"])){
// CONNECT TO THE DATABASE
$db_conx = include_once("php_includes/db_connect.php");
// GATHER THE POSTED DATA INTO LOCAL VARIABLES
$u = preg_replace('#[^a-z0-9]#i', '', $_POST['u']);
$e = mysqli_real_escape_string($db_conx, $_POST['e']);
$p = $_POST['p'];
$g = preg_replace('#[^a-z]#', '', $_POST['g']);
$c = preg_replace('#[^a-z ]#i', '', $_POST['c']);
// GET USER IP ADDRESS
$ip = preg_replace('#[^0-9.]#', '', getenv('REMOTE_ADDR'));
// DUPLICATE DATA CHECKS FOR USERNAME AND EMAIL
$sql = "SELECT id FROM users WHERE username='$u' LIMIT 1";
$query = mysqli_query($db_conx, $sql);
$u_check = mysqli_num_rows($query);
// -------------------------------------------
$sql = "SELECT id FROM users WHERE email='$e' LIMIT 1";
$query = mysqli_query($db_conx, $sql);
$e_check = mysqli_num_rows($query);
// FORM DATA ERROR HANDLING
if($u == "" || $e == "" || $p == "" || $g == "" || $c == ""){
echo "The form submission is missing values.";
exit();
} else if ($u_check > 0){
echo "The username you entered is alreay taken";
exit();
} else if ($e_check > 0){
echo "That email address is already in use in the system";
exit();
} else if (strlen($u) < 3 || strlen($u) > 16) {
echo "Username must be between 3 and 16 characters";
exit();
} else if (is_numeric($u[0])) {
echo 'Username cannot begin with a number';
exit();
} else {
// END FORM DATA ERROR HANDLING
// Begin Insertion of data into the database
// Hash the password and apply your own mysterious unique salt
$cryptpass = crypt($p);
include_once ("php_includes/randStrGen.php");
$p_hash = randStrGen(20)."$cryptpass".randStrGen(20);
// Add user info into the database table for the main site table
$sql = "INSERT INTO users (username, email, password, gender, country, ip, signup, lastlogin, notescheck)
VALUES('$u','$e','$p_hash','$g','$c','$ip',now(),now(),now())";
$query = mysqli_query($db_conx, $sql);
$uid = mysqli_insert_id($db_conx);
// Establish their row in the useroptions table
$sql = "INSERT INTO useroptions (id, username, background) VALUES ('$uid','$u','original')";
$query = mysqli_query($db_conx, $sql);
// Create directory(folder) to hold each user's files(pics, MP3s, etc.)
if (!file_exists("user/$u")) {
mkdir("user/$u", 0755);
}
// Email the user their activation link
$to = "$e";
$from = "auto_responder@dragonsdengamming.com";
$subject = 'Dragons Den Gaming Account Activation';
$message = '<!DOCTYPE html><html><head><meta charset="UTF-8"><title>Dragons Den Gaming</title></head><body style="margin:0px; font-family:Tahoma, Geneva, sans-serif;"><div style="padding:10px; background:#333; font-size:24px; color:#CCC;"><a href="http://www.yoursitename.com"><img src="images/logo.png" width="200" height="200" alt="yoursitename" style="border:none; float:left;"></a>yoursitename Account Activation</div><div style="padding:24px; font-size:17px;">Hello '.$u.',<br /><br />Click the link below to activate your account when ready:<br /><br /><a href="http://www.yoursitename.com/activation.php?id='.$uid.'&u='.$u.'&e='.$e.'&p='.$p_hash.'">Click here to activate your account now</a><br /><br />Login after successful activation using your:<br />* E-mail Address: <b>'.$e.'</b></div></body></html>';
$headers = "From: $from\n";
$headers .= "MIME-Version: 1.0\n";
$headers .= "Content-type: text/html; charset=iso-8859-1\n";
mail($to, $subject, $message, $headers);
echo "signup_success";
exit();
}
exit();
}