如何在一个php文件中定义mysqli连接，然后在另一个文件中使用它？

小编典典

如何在一个php文件中定义mysqli连接，然后在另一个文件中使用它？

sql

我是PHP的新手，我使用Eclipse SDE构建一个简单的Web应用程序。

我的方案是：

我有 index.php 页面，其中包括登录表单（ 2个文本框和Login Button ）
我有包含两个表的MySQL数据库：system_users和user_errors
每当用户成功在index.php页面中登录时，这都应将其重定向到 page1.php ，然后从user_errors表中检索其错误并将其列出。

我想在php中实现这一点。

以下是我的代码：

index.php

    <html>

<link rel="stylesheet" type="text/css" href="cssDesign.css">

<head>
<title>A BASIC HTML FORM</title>
<?PHP

//MySQL Database Connect 
include 'mysql_connect.php';

$conn = MySQLConnection::getConnection();


// Create connection
//global $con;
//$con = new mysqli("192.168.0.2", "Invest", "NeeD$123","investmentprojects","3306");

if (isset($_POST['Submit1'])) {
    $username = $_POST['username'];
    $password = $_POST['password'];

$result = mysqli_query($conn,"SELECT id,username,password,type FROM system_users WHERE username = '".$username."' AND password='".$password."' ");
$rows = mysqli_num_rows($result);

if ($rows == 1) {
  header('Location: page1.php');
}       
else {
    print ("You're not a member of this site");
    }
}

//mysqli_close($conn);

?>

</head>
<body>

<FORM NAME ="form1" METHOD ="POST" ACTION = "index.php">

<table border="0" style="width:370px;border:0px;">
    <tr> 
        <td style ="width:30%;border:0px;">User</td>
        <td style ="width:70%;;border:0px;"><INPUT style ="width:100%;" TYPE = "TEXT" VALUE ="" NAME = "username"> </td>
    </tr>
    <tr> 
        <td style ="width:30%;border:0px;">Password</td>
        <td style ="width:70%;border:0px;"><INPUT style ="width:100%;" TYPE = "TEXT" VALUE ="" NAME = "password"> </td>
    </tr>
    <tr> 
    <td style ="width:30%;border:0px;"></td>
        <td align='right' style ="width:70%;border:0px;"><INPUT style ="width:30%;" TYPE = "Submit" Name = "Submit1" VALUE = "Login"> </td>
    </tr>

</table>


</FORM>

</body>
</html>

page1.php

    <html>

<link rel="stylesheet" type="text/css" href="cssDesign.css">

<head>
<title>A BASIC HTML FORM</title>
</head>
<body>

<Form name ="form1" Method ="POST" Action ="page1.php">

</FORM>

</body>
</html>

<?php

include 'mysql_connect.php';

$conn = MySQLConnection::getConnection();

$username = $_POST['username'];

$sql = "SELECT user_name,error_form,error_date,error_description " . 
        "FROM error_log WHERE username ='".$username."'";

$result = mysqli_query($conn,$sql);

if ($result->num_rows > 0) {
    echo "<table>";
        echo "<tr>";
        echo "<th>User</th><th>Error Form</th><th>Error Date</th><th>Error Description</th>";
        echo "</tr>";
    // output data of each row

    while($row = $result->fetch_assoc()) {
        echo "<tr>";
        echo "<td>".$row["user_name"]."</td>";
        echo "<td>".$row["error_form"]."</td>";
        echo "<td>".$row["error_date"]."</td>";
        echo "<td>".$row["error_description"]."</td>";
        echo "</tr>";
    }
    echo "</table>";

} else {
    echo "0 results";
}

//mysqli_close($conn);
?>

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2021-04-07

共1个答案

小编典典

使文件connection.php与所有与mysql连接相切的文件以及在使用mysql的每个文件中的ad之后查询该行，include_once('connection.php');或者可以
include_once('some_folder\connection.php');

如果您是初学者，则可以使用此模式连接到数据库

mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$link = mysqli_connect('localhost', 'mysql_user', 'mysql_password');
echo 'Connected successfully';

$res = mysqli_query($link, "CREATE TEMPORARY TABLE myCity LIKE City");

http://php.net/manual/zh/mysqli.query.php

2021-04-07