这将是漫长的，所以要做好准备
我制作了这个系统，在其上编辑，删除，添加，显示数据库中的数据。我最初在Mysql中编程了它，但后来想要mysqli中的代码。所以我基本上做的是添加＆＃34;我＆＃34;之后我写了mysql。我有一堆页面。
id是bell_no
firstname是bell_amount
姓氏是bell_time
期间是bell_period
^我已将这些用作评论中的那些
（database.php中）
<?php
$servername = "localhost";
$username = "root";
$password = "";
$db = 'bell_database';
// Create connection
$conn = mysqli_connect($servername, $username, $password, $db);
// Check connection
if (!$conn) {
die("Connection failed: " . mysqli_connect_error());
}
?>
（view.php）
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<title>View Records</title>
</head>
<body>
<?php
/*
VIEW.PHP
Displays all data from 'players' table
*/
// connect to the database
include('database.php');
// get results from database
$result = mysqli_query("SELECT * FROM bell_db")
or die(mysqli_error());
// display data in table
echo "<p><b>View All</b> | <a href='view-paginated.php?page=1'>View Paginated</a></p>";
echo "<table border='1' cellpadding='10'>";
echo "<tr> <th>Bell No.</th> <th>No. of Rings</th> <th>Time</th> <th>Period</th> <th></th> <th></th></tr>";
// loop through results of database query, displaying them in the table
while($row = mysqli_fetch_array( $result )) {
// echo out the contents of each row into a table
echo "<tr>";
echo '<td>' . $row['bell_no'] . '</td>';
echo '<td>' . $row['bell_amount'] . '</td>';
echo '<td>' . $row['bell_time'] . '</td>';
echo '<td>' . $row['bell_period'] . '</td>';
echo '<td><a href="edit.php?bell_no=' . $row['bell_no'] . '">Edit</a></td>';
echo '<td><a href="delete.php?bell_no=' . $row['bell_no'] . '">Delete</a></td>';
echo "</tr>";
}
// close table>
echo "</table>";
?>
<p><a href="new.php">Add a new record</a></p>
</body>
</html>
new.php
<?php
/*
NEW.PHP
Allows user to create a new entry in the database
*/
// creates the new record form
// since this form is used multiple times in this file, I have made it a function that is easily reusable
function renderForm($bell_amount, $bell_time, $bell_period, $error)
{
?>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<title>New Record</title>
</head>
<body>
<?php
// if there are any errors, display them
if ($error != '')
{
echo '<div style="padding:4px; border:1px solid red; color:red;">'.$error.'</div>';
}
?>
<form action="" method="post">
<div>
<strong>No. Of Bells: *</strong> <input type="text" name="bell_amount" value="<?php echo $bell_amount; ?>" /><br/>
<strong>Time: *</strong> <input type="text" name="bell_time" value="<?php echo $bell_time; ?>" /><br/>
<strong>Period: *</strong> <input type="text" name="bell_period" value="<?php echo $bell_period; ?>" /><br/>
<p>* required</p>
<input type="submit" name="submit" value="Submit">
</div>
</form>
</body>
</html>
<?php
}
// connect to the database
include('database.php');
// check if the form has been submitted. If it has, start to process the form and save it to the database
if (isset($_POST['submit']))
{
// get form data, making sure it is valid
$bell_amount = mysqli_real_escape_string(htmlspecialchars($_POST['bell_amount']));
$bell_time = mysqli_real_escape_string(htmlspecialchars($_POST['bell_time']));
$bell_period = mysqli_real_escape_string(htmlspecialchars($_POST['bell_period']));
// check to make sure both fields are entered
if ($bell_amount == '' || $bell_time == '' || $bell_period == '')
{
// generate error message
$error = 'ERROR: Please fill in all required fields!';
// if either field is blank, display the form again
renderForm($bell_amount, $bell_time, $bell_period, $error);
}
else
{
// save the data to the database
mysqli_query("INSERT bell_db SET bell_amount='$bell_amount', bell_time='$bell_time', bell_period='$bell_period'")
or die(mysql_error());
// once saved, redirect back to the view page
header("Location: view.php");
}
}
else
// if the form hasn't been submitted, display the form
{
renderForm('','','');
}
?>
（edit.php）
<?php
/*
EDIT.PHP
Allows user to edit specific entry in database
*/
// creates the edit form
// since this form is used multiple times in this file, I have made it a function that is easily reusable
function renderForm($bell_no, $bell_amount, $bell_time, $bell_period, $error)
{
?>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<title>Edit Record</title>
</head>
<body>
<?php
// if there are any errors, display them
if ($error != '')
{
echo '<div style="padding:4px; border:1px solid red; color:red;">'.$error.'</div>';
}
?>
<form action="" method="post">
<input type="hidden" name="bell_no" value="<?php echo $bell_no; ?>"/>
<div>
<p><strong>Bell No.:</strong> <?php echo $bell_no; ?></p>
<strong>No Of Rings: *</strong> <input type="text" name="bell_amount" value="<?php echo $bell_amount; ?>"/><br/>
<strong>Time: *</strong> <input type="text" name="bell_time" value="<?php echo $bell_time; ?>"/><br/>
<strong>Period: *</strong> <input type="text" name="bell_period" value="<?php echo $bell_period; ?>"/><br/>
<p>* Required</p>
<input type="submit" name="submit" value="Submit">
</div>
</form>
</body>
</html>
<?php
}
// connect to the database
include('database.php');
// check if the form has been submitted. If it has, process the form and save it to the database
if (isset($_POST['submit']))
{
// confirm that the 'id' value is a valid integer before getting the form data
if (is_numeric($_POST['bell_no']))
{
// get form data, making sure it is valid
$bell_no = $_POST['bell_no'];
$bell_amount = mysqli_real_escape_string(htmlspecialchars($_POST['bell_amount']));
$bell_time = mysqli_real_escape_string(htmlspecialchars($_POST['bell_time']));
$bell_period = mysqli_real_escape_string(htmlspecialchars($_POST['bell_period']));
// check that firstname/lastname fields are both filled in
if ($bell_amount == '' || $bell_time == '' || $bell_period == '')
{
// generate error message
$error = 'ERROR: Please fill in all required fields!';
//error, display form
renderForm($bell_no, $bell_amount, $bell_time, $bell_period, $error);
}
else
{
// save the data to the database
mysqli_query("UPDATE bell_db SET bell_amount='$bell_amount', bell_time='$bell_time', bell_period='$bell_period' WHERE bell_no='$bell_no'")
or die(mysql_error());
// once saved, redirect back to the view page
header("Location: view.php");
}
}
else
{
// if the 'id' isn't valid, display an error
echo 'Error!';
}
}
else
// if the form hasn't been submitted, get the data from the db and display the form
{
// get the 'id' value from the URL (if it exists), making sure that it is valid (checing that it is numeric/larger than 0)
if (isset($_GET['bell_no']) && is_numeric($_GET['bell_no']) && $_GET['bell_no'] > 0)
{
// query db
$bell_no = $_GET['bell_no'];
$result = mysqli_query("SELECT * FROM bell_db WHERE bell_no=$bell_no")
or die(mysqli_error());
$row = mysqli_fetch_array($result);
// check that the 'id' matches up with a row in the databse
if($row)
{
// get data from db
$bell_amount = $row['bell_amount'];
$bell_time = $row['bell_time'];
$bell_period = $row['bell_period'];
// show form
renderForm($bell_no, $bell_amount, $bell_time, $bell_period, '');
}
else
// if no match, display result
{
echo "No results!";
}
}
else
// if the 'id' in the URL isn't valid, or if there is no 'id' value, display an error
{
echo 'Error!';
}
}
?>
（delete.php）
<?php
/*
DELETE.PHP
Deletes a specific entry from the 'players' table
*/
// connect to the database
include('database.php');
// check if the 'id' variable is set in URL, and check that it is valid
if (isset($_GET['bell_no']) && is_numeric($_GET['bell_no']))
{
// get id value
$bell_no = $_GET['bell_no'];
// delete the entry
$result = mysqli_query("DELETE FROM bell_db WHERE bell_no=$bell_no")
or die(mysqli_error());
// redirect back to the view page
header("Location: view.php");
}
else
// if id isn't set, or isn't valid, redirect back to view page
{
header("Location: view.php");
}
?>
<br>
这些是我建立的所有页面。数据库名为bell_db。它有4列bell_no bell_amount bell_time和bell_period 现在.. database.php工作正常。当我运行view.php时显示以下错误： - 警告：mysqli_query（）需要至少2个参数，1在第18行的D：\ xampp \ htdocs \ bell \ view.php中给出
警告：mysqli_error（）预计在第19行D：\ xampp \ htdocs \ bell \ view.php中给出1个参数0
当我运行new.php。它显示了表单，但在它上面，它显示了
警告：缺少renderForm（）的参数4，在第76行的D：\ xampp \ htdocs \ bell \ new.php中调用，在第9行的D：\ xampp \ htdocs \ bell \ new.php中定义
注意：未定义的变量：第20行的D：\ xampp \ htdocs \ bell \ new.php中的错误 当我填写表格中的东西并按下输入时说明 警告：mysqli_real_escape_string（）正好需要2个参数，1在第50行的D：\ xampp \ htdocs \ bell \ new.php中给出
警告：mysqli_real_escape_string（）正好需要2个参数，1在第51行的D：\ xampp \ htdocs \ bell \ new.php中给出
警告：mysqli_real_escape_string（）正好需要2个参数，第5行给出D：\ xampp \ htdocs \ bell \ new.php
错误：请填写所有必填字段！
如果我打开edit.php它只显示错误！
当我打开delete.php返回view.php
我是这个东西的初学者..所以有人能告诉我出了什么问题吗？
答案 0 :(得分：1)
对于mysql，您只需连接一次数据库，而对于mysqli，您必须将该连接传递给查询。例如
$result = mysqli_query($conn, "SELECT * FROM bell_db"); //$conn is your connection variable that you have declared in your code
如上所述，只需将 $ conn 添加到所有mysqli_query
就是这样。它现在会工作...... 您可以查看文档mySqli
答案 1 :(得分：1)
将$ conn添加到mysqli _ *
与view.php一样，更改此行
$result = mysqli_query("SELECT * FROM bell_db")
or die(mysqli_error());
到
$result = mysqli_query($conn, "SELECT * FROM bell_db")
or die(mysqli_error($conn));
对其他文件进行更改。
答案 2 :(得分：1)
您需要连接一次
$db = new mysqli($host,$username,$passwd, $dbname);
然后将此对象用于您的查询
$result = $db->query(' SELECT `foo` FROM `bar` WHERE `foofoo`=88 ');
答案 3 :(得分：1)
您必须提供两个参数来传递Mysqli查询中的值。
您必须为数据库的每个条目提供$conn连接查询。
示例：
$result = mysqli_query($conn, "SELECT * FROM bell_db")