Question

我的PHP如下。这总共是两个文件

对于“ dbh.php”：

<?php

$server = "localhost";
$username = "root";
$password = "";
$name = "login_system";

$con = mysqli_connect("localhost","username","","login_system");
if (mysqli_connect_errno())
  {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
  }


?>

对于“ index3.php”：

<?php 
    include'dbh.php';
?>
<!DOCTYPE html>
<html>
    <head>
        <title> It is index 3</title>
    </head>
    <body>
    <?php
        global $con;
        $sql = "SELECT * FROM users;"; 
        $result = mysqli_query($con,$sql );
        $resultCheck = mysqli_num_rows($result);

        if ($resultCheck > 0){
            while($row = mysqli_fetch_assoc(result)){
                echo $row['useruid'] . "<br>";
            }
        }
    ?>

    </body>
</html>

执行此操作时出现错误。

Warning: mysqli_query() expects parameter 1 to be mysqli, null given in C:\xampp\htdocs\phplesson\index3.php on line 13

Warning: mysqli_num_rows() expects parameter 1 to be mysqli_result, null given in C:\xampp\htdocs\phplesson\index3.php on line 14

这是否意味着我遇到了连接问题？还是其他问题？

另外，我该如何解决？

感谢帮助！

Answer 1

在下面替换“ dbh.php”的代码：

<?php
$server = "localhost";
$username = "root";
$password = "";
$db_name = "testc";
$con = mysqli_connect($server,$username,$password,$db_name);
if (mysqli_connect_errno())
  {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
  }
?>

在下面替换“ index3.php”的代码：

<?php 
    include'db.php';
?>
<!DOCTYPE html>
<html>
    <head>
        <title> It is index 3</title>
    </head>
    <body>
    <?php
        $sql = "SELECT * FROM users;"; 
        $result = mysqli_query($con,$sql);
        $resultCheck = mysqli_num_rows($result);
        if ($resultCheck > 0){
            while($row = mysqli_fetch_assoc($result)){
                echo $row['useruid'] . "<br>";
            }
        }
    ?>
    </body>
</html>

sqli和数据库连接问题？

1 个答案: