#2 create and populate a database && realistic and practical applications (PART 2)
Extends from the last chapter , This chapter takes a look at some real-world problems that can occur as you move your application
from testing to a live website, Through this chapter you will learn more important PHP and SQL code.
First Problem : Its never safe to assume a web form will be used exactly the way it was intended.
SO try and head off these kinds of problems by anticipating that some users will misuse your forms.
So the form is in need of validation, which is the process of checking to make sure form data is OK before doing anything with it.
Validation means making the data you get is the data you expect .
Just a tip here: you can also validating data on the client by JavaScript. But the server is the last line of defense for catching bad form data,
So server-side validation can't be ignored even if you have checked the data on the client-side.
Above the last project, we should add some code to sendemail.php that examines the values in the text boxes and checks to make
sure they aren't empty. If everything checks out OK, the script sends out the emails.
A form that references itself. An HTML form that is part of the PHP script that process it is known as self-referencing.(自引用表格，表格会提交到自身)
When a form is smart enough to remember data entered into it in prior submissions, its know as a sticky form, data sticks to it!
you can make the sendemail.php a self-referencing form like this :
<form action="sendemail.php" method="post">
or you can do it like this :
<form action="<?php echo $_SERVER['PHP_SELF']; ?>" method="post">
superglobal variable $_SERVER['PHP_SELF'], which stores the name of the current script. You can replace the script URL in the form action to
$_SERVER['PHP_SELF'], and not ever have to worry about updating anything if you ever need to rename the script.
To make the form Validation and Sticky , you can edit the sendemail.php like this :
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Make Me Elvis - Send Email</title>
<link rel="stylesheet" type="text/css" href="style.css" />
</head>
<body>
<img src="blankface.jpg" width="161" height="350" alt="" style="float:right" />
<img name="elvislogo" src="elvislogo.gif" width="229" height="32" border="0" alt="Make Me Elvis" />
<p><strong>Private:</strong> For Elmer's use ONLY<br />
Write and send an email to mailing list members.</p> <?php
if (isset($_POST['submit'])) {
$from = 'elmer@makemeelvis.com';
$subject = $_POST['subject'];
$text = $_POST['elvismail'];
$output_form = false; if (empty($subject) && empty($text)) {
// We know both $subject AND $text are blank
echo 'You forgot the email subject and body text.<br />';
$output_form = true;
} if (empty($subject) && (!empty($text))) {
echo 'You forgot the email subject.<br />';
$output_form = true;
} if ((!empty($subject)) && empty($text)) {
echo 'You forgot the email body text.<br />';
$output_form = true;
}
}
else {
$output_form = true;
} if ((!empty($subject)) && (!empty($text))) {
$dbc = mysqli_connect("localhost","root","root","elvis_store")
or die("Error connectiong to MySQL");
echo "Connecting success! </br>"; $query = "SELECT * FROM email_list";
$result = mysqli_query($dbc, $query)
or die("Error querying database!");
echo "Quering success! </br>"; while( $row = mysqli_fetch_array($result) ) {
$first_name = $row['first_name'];
$last_name = $row['last_name'];
$to = $row['email']; $msg = "Dear $first_name $last_name, \n $text"; mail($to, $subject, $msg, 'From: '.$from ); echo 'Emai sent to :'.$to. "<br/>";
}
mysqli_close($dbc);
} if ($output_form) {
?> <form method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>">
<label for="subject">Subject of email:</label><br />
<input id="subject" name="subject" type="text" value="<?php echo $subject; ?>" size="30" /><br />
<label for="elvismail">Body of email:</label><br />
<textarea id="elvismail" name="elvismail" rows="8" cols="40"><?php echo $text; ?></textarea><br />
<input type="submit" name="submit" value="Submit" />
</form> <?php
}
?> </body>
</html>
Next we should the alter the table to make table rows should be uniquely identifialbe.
SQL has a command that lets you make changes to an existing table without losing any data.
ALTER TABLE table_name ADD column_name column_type
you can use it like this :
ALTER TABLE email_list ADD id INT NOT NULL AUTO_INCREMENT FIRST,
ADD PRIMARY KEY(id) #this little chunk of code tells MySQL that new id column is the primary key for the table, you can learn more detail here
After you have changed the database, you should also add validation to the addemail.php just like what we did before:
<?
/**
* Created by IntelliJ IDEA.
* User: beyond_acm
* Date: 9/1/2015
* Time: 9:58 AM
*/
?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Make Me Elvis - Add Email</title>
<link rel="stylesheet" type="text/css" href="style.css" />
</head>
<body>
<img src="blankface.jpg" width="161" height="350" alt="" style="float:right" />
<img name="elvislogo" src="elvislogo.gif" width="229" height="32" border="0" alt="Make Me Elvis" />
<p>Enter your first name, last name, and email to be added to the <strong>Make Me Elvis</strong> mailing list.</p> <?php
if( isset($_POST['submit']) ) {
// if submit the form
$first_name = $_POST['firstname'];
$last_name = $_POST['lastname'];
$email = $_POST['email'];
$output_form = 'no';
//TODO the validation
if (empty($first_name) || empty($last_name) || empty($email)) {
// We know at least one of the input fields is blank
echo 'Please fill out all of the email information.<br />';
$output_form = 'yes';
}
} else {
$output_form = 'yes';
}
//If the form is validate, then todo insert the data into the database
if (!empty($first_name) && !empty($last_name) && !empty($email)) {
$dbc = mysqli_connect('localhost', 'root', 'root', 'elvis_store')
or die('Error connecting to MySQL server.'); $query = "INSERT INTO email_list (first_name, last_name, email) VALUES ('$first_name', '$last_name', '$email')";
mysqli_query($dbc, $query)
or die ('Data not inserted.'); echo 'Customer added.'; mysqli_close($dbc);
}
if ($output_form == 'yes') {
?>
<form method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>">
<label for="firstname">First name:</label>
<input type="text" id="firstname" name="firstname" /><br />
<label for="lastname">Last name:</label>
<input type="text" id="lastname" name="lastname" /><br />
<label for="email">Email:</label>
<input type="text" id="email" name="email" /><br />
<input type="submit" name="submit" value="Submit" />
</form> <?php
}
?> </body>
</html>
Last we should add a removeemail.php to delete users from the table, the removeemail.php is as followed :
<?
/**
* Created by IntelliJ IDEA.
* User: Administrator
* Date: 9/1/2015
* Time: 10:29 AM
*/
?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Make Me Elvis - Remove Email</title>
<link rel="stylesheet" type="text/css" href="style.css" />
</head>
<body>
<img src="blankface.jpg" width="161" height="350" alt="" style="float:right" />
<img name="elvislogo" src="elvislogo.gif" width="229" height="32" border="0" alt="Make Me Elvis" />
<p>Please select the email addresses to delete from the email list and click Remove.</p> <form action="<?php echo $_SERVER['PHP_SELF']; ?>" method="post">
<?php
$dbc = mysqli_connect('localhost', 'root', 'root', 'elvis_store')
or die('Error connecting to MySQL server'); //Delete the customer rows (only if the form has been submitted)
if( isset($_POST['submit']) ) {
foreach( $_POST['todelete'] as $delete_id ) {
$query = "DELETE FROM email_list WHERE id = $delete_id";
mysqli_query($dbc, $query)
or die('Error quering database');
}
echo 'Customer(s) removed. </br>';
} //Display the customer rows with checkboxed for deleting
$query = "SELECT * FROM email_list";
$result = mysqli_query($dbc, $query);
while( $row = mysqli_fetch_array($result) ) {
echo '<input type="checkbox" value=' .$row['id']. ' name="todelete[]" />';
echo $row['first_name'];
echo ' '.$row['last_name'];
echo ' '.$row['email'];
echo '</br>';
}
mysqli_close($dbc);
?>
<input type="submit" name="submit" value="Remove">
</form> </body>
</html>
if you get it right, you should see some pages as follows :
Now you can delete the registerd user stored in the database, Cool you have finished a real webapp.
#2 create and populate a database && realistic and practical applications (PART 2)的更多相关文章
- #2 create and populate a database && realistic and practical applications
The Chapter3 & Chapter4 of this book tells you how to create a realistic app on the web through ...
- Create a SQL Server Database on a network shared drive
(原文地址:http://blogs.msdn.com/b/varund/archive/2010/09/02/create-a-sql-server-database-on-a-network-sh ...
- [转]How to: Create a Report Server Database (Reporting Services Configuration)
本文转自:https://docs.microsoft.com/en-us/previous-versions/sql/sql-server-2008-r2/ms157300%28v%3dsql.10 ...
- Create an Azure SQL database in the Azure portal
Create a SQL database An Azure SQL database is created with a defined set of compute and storage res ...
- [Windows Azure] How to Create and Configure SQL Database
How to Create and Configure SQL Database In this topic, you'll step through logical server creation ...
- HiveSQLException: Error while compiling statement: No privilege 'Create' found for outputs { database:default }
今天用Hive的JDBC实例时出现了HiveSQLException: Error while compiling statement: No privilege 'Create' found for ...
- [odb-users] Create schema error (unknown database schema '')
Boris Kolpackov boris at codesynthesis.comFri May 31 11:13:02 EDT 2013 Previous message: [odb-users] ...
- [置顶] How to create Oracle 11g R2 database manually in ASM?
Step 1: Specify an Instance Identifier (SID) export ORACLE_SID=maomi Step 2: Ensure That the Require ...
- Create schema error (unknown database schema '')
Andrey Devyatka 4 years ago Permalink Raw Message Hi,Please tell me, can I use the static library in ...
随机推荐
- 开发原则&设计模式
1.关于软件开发中的开发原则和设计模式: 1.1.开发原则 1.1.1.什么是开发原则? 开发原则就是开发的依据,只要依照这些原则进行开发,将来开发的软件具有很强的扩展力,很低的耦合度. 开发原则不属 ...
- ifream页面弹出框遮盖层覆盖父页面
1.首先找到子页面上遮罩层的id, 2.然后再父页面编写个js方法 function shade() { $(".layui-layer-shade").height($(wind ...
- JAVA反射练习
JAVA反射练习 题目 实现一个方法 public static Object execute(String className, String methodName, Object args[]) ...
- 从零开始的全栈工程师——html篇1.6
浮动与伪类选择器 一.浮动(float) 1.标准文档流 标准文档流是一种默认的状态 浏览器的排版是根据元素的特征(块和行级) 从上往下 从左往右排版 这就是标准文档流 2.浮动(float)floa ...
- javascript中call()、apply()、bind()的用法理解
一.bind的用法 第一个:obj.showInfo('arg','arg_18');中传的2个参数通过showInfo方法改变的是obj下中的name和age 第二个:obj.showInfo.bi ...
- 利用binlog2sql解析mysqlbinlog row行日志
binlog2sql 项目作者:曹单锋 github项目地址:https://github.com/danfengcao/binlog2sql 也可在github.com上搜索“binlog2sql” ...
- Head First HTML与CSS阅读笔记（一）
之前写过不少前端界面,但是没有完整阅读过一本HTML与CSS的书籍,都是用到什么查什么,最近闲暇之余想巩固加深一下前端基础方面的知识,阅读了<Head First HTML与CSS>,感觉 ...
- js 对象字面量
对象字面量的输出方式以及定义好处 1.对象字面量的输出方式有两种:传统的'.' 例如:box.name 以及数组方式,只不过用数组方式输出时,方括号里面要用引号括起来 例如:box['name'] v ...
- 【BZOJ2427】[HAOI2010] 软件安装（缩点+树形DP）
点此看题面 大致题意: 有\(N\)个软件,每个软件有至多一个依赖以及一个所占空间大小\(W_i\),只有当一个软件的直接依赖和所有的间接依赖都安装了,它才能正常工作并造成\(V_i\)的价值.求在容 ...
- 动态规划专题（二）——树形DP
前言 \(DP\)这东西真的是博大精深啊...... 简介 树形\(DP\),顾名思义,就是在树上操作的\(DP\),一般可以用\(f_i\)表示以编号为\(i\)的节点为根的子树中的最优解. 转移的 ...