1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
|
<?php
declare(strict_types=1);
error_reporting(E_ALL);
// student: name roll city email date_of_birth
function connect_to_database() {
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
if (!($dbh = mysqli_connect('localhost', 'root', '')))
display_failure('Could not connect to the database: ' . mysqli_connect_error($dbh));
mysqli_set_charset($dbh, 'utf8mb4');
if (!mysqli_query($dbh, 'CREATE DATABASE IF NOT EXISTS STUDENTS_DB'))
display_failure('Could not create database: ' . mysqli_error($dbh));
mysqli_select_db($dbh, 'STUDENTS_DB');
if (!mysqli_query($dbh, 'CREATE TABLE IF NOT EXISTS STUDENT (
ROLL INT(20) PRIMARY KEY,
NAME VARCHAR(255),
CITY VARCHAR(255),
EMAIL VARCHAR(255),
DATE_OF_BIRTH DATE
)'))
display_failure('Could not create table: ' . mysqli_error($dbh));
return $dbh;
}
function html_prologue($title) {
?><!doctype html>
<meta charset="utf-8">
<title><?php echo $title; ?></title>
<style>
body { font-family: sans-serif; font-size: 1.3rem; }
h1 { font-size: 2rem; font-weight: 500; }
form { margin: 2em auto; width: 20em; }
form input { float: right; }
form input[type=submit] { float: none; display: block; margin: 0 auto; }
form > * { display: block; padding: 0.5em; }
table, tr, th, td { border-collapse: collapse; border: 1px solid black; }
table.record th { text-align: left; }
th, td { padding: 5px; }
main ul li { list-style-type: square; }
p.error { padding: 2em; background-color: #eeccbb; }
</style>
<?php
}
function display_menu() {
html_prologue('Student operations menu');
$php = $_SERVER['SCRIPT_NAME'];
?>
<main>
<h1>Menu of operations on records of students</h1>
<ul>
<li><a href="<?php echo $php; ?>/insert">Insert record of a student</a></li>
<li><a href="<?php echo $php; ?>/display">Display records of all students</a></li>
<li><a href="<?php echo $php; ?>/disp-dob-range">Display records of students born in between 2000-01-01 and 2005-12-31</a></li>
<li><a href="<?php echo $php; ?>/search">Search for the record of a student using E-mail address</a></li>
</ul>
</main>
<?php
}
function display_search_form() {
html_prologue('Student details');
/* $_SERVER['PHP_SELF'] is approximately equal to $_SERVER['SCRIPT_NAME'] . $_SERVER['PATH_INFO'] */
?>
<form action="<?php echo $_SERVER['PHP_SELF']; ?>">
<h2>Enter E-mail address to search for the record of a student</h2>
<label>E-mail: <input type="email" name="email"></label>
<input type="submit" value="Search">
</form>
<?php
}
function display_insert_form() {
html_prologue('Student details');
?>
<form method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>">
<h1>Enter student's details</h1>
<label>Name: <input type="text" name="name"></label>
<label>Roll No.: <input type="number" name="roll"></label>
<label>City: <input type="text" name="city"></label>
<label>Email: <input type="email" name="email"></label>
<label>Date of birth: <input type="date" name="date_of_birth"></label>
<input type="submit" value="Submit">
</form>
<?php
}
function display_success() {
html_prologue('Operation successful');
?>
<h2>Insertion successful.</h2>
<?php
}
function display_failure($reason) {
html_prologue('Operation failure');
?>
<h2>Operation failed</h2>
<p>Reason: <?php echo $reason; ?></p>
<?php
die();
}
function check_post_vars($vardesc) {
$vars = [];
foreach ($vardesc as $name => $desc) {
if (!isset($_POST[$name]) || empty($_POST[$name]))
display_failure('The ' . $desc . ' field can not be empty');
$vars[$name] = $_POST[$name];
}
return $vars;
}
function insert_details($dbh) {
$vars = check_post_vars([
'name' => 'Name',
'email' => 'E-mail address',
'date_of_birth' => 'Date of birth',
'city' => 'City',
'roll' => 'Roll No.'
]);
$stmt = mysqli_prepare($dbh, 'INSERT INTO STUDENT (ROLL, NAME, EMAIL, CITY, DATE_OF_BIRTH) VALUES (?,?,?,?,?)');
mysqli_stmt_bind_param($stmt, 'sssss', $vars['roll'], $vars['name'], $vars['email'], $vars['city'], $vars['date_of_birth']);
mysqli_stmt_execute($stmt);
}
function show_table($result) { ?>
<table>
<tr>
<th>Roll No.</th>
<th>Name</th>
<th>E-mail</th>
<th>City</th>
<th>Date of birth</th>
</tr>
<?php while ($row = mysqli_fetch_assoc($result)) { ?>
<tr><td>
<?php echo implode('</td><td>', array_map('htmlspecialchars', [$row['ROLL'], $row['NAME'], $row['EMAIL'], $row['CITY'], $row['DATE_OF_BIRTH']])); ?>
</td></tr>
<?php } ?>
</table>
<?php }
function show_table_normal($dbh) {
if(!($result = mysqli_query($dbh, 'SELECT * FROM STUDENT')))
display_failure('Could not perform query: ' . mysqli_error($dbh));
html_prologue('Students\' details');
?>
<h2>Students' details</h2>
<p><?php echo mysqli_num_rows($result); ?> record(s) found.</p>
<?php
show_table($result);
}
function show_table_dob_range($dbh) {
if (!($result = mysqli_query($dbh, 'SELECT * FROM STUDENT WHERE YEAR(DATE_OF_BIRTH) BETWEEN 2000 AND 2005')))
display_failure('Could not perform query: ' . mysqli_error($dbh));
html_prologue('Students\' details');
?>
<h2>Students' details</h2>
<p>The students who were born in years 2000 to 2005, inclusive.</p>
<p><?php echo mysqli_num_rows($result); ?> record(s) found.</p>
<?php
show_table($result);
}
function search_student($dbh, $email) {
$stmt = mysqli_prepare($dbh, 'SELECT * FROM STUDENT WHERE EMAIL = ?');
mysqli_stmt_bind_param($stmt, 's', $email);
mysqli_stmt_execute($stmt);
$result = mysqli_stmt_get_result($stmt);
if (mysqli_num_rows($result) === 0) return null;
return mysqli_fetch_array($result);
}
function show_record($record) {
html_prologue('Student record');
?>
<h1>Record of the student</h1>
<table class="record">
<tr><th>Roll No.</th> <td><?php echo $record['ROLL']; ?></td></tr>
<tr><th>Name</th> <td><?php echo $record['NAME']; ?></td></tr>
<tr><th>E-mail</th> <td><?php echo $record['EMAIL']; ?></td></tr>
<tr><th>City</th> <td><?php echo $record['CITY']; ?></td></tr>
<tr><th>Date of birth</th> <td><?php echo $record['DATE_OF_BIRTH']; ?></td></tr>
</table>
<?php
}
if (!isset($_SERVER['PATH_INFO']) || empty($_SERVER['PATH_INFO']) || $_SERVER['PATH_INFO'] == '/') {
display_menu();
die();
}
$path = ltrim($_SERVER['PATH_INFO'], '/');
if ($path === 'insert') {
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
$dbh = connect_to_database();
insert_details($dbh);
display_success();
mysqli_close($dbh);
} else {
display_insert_form();
}
} elseif ($path === 'display') {
$dbh = connect_to_database();
show_table_normal($dbh);
mysqli_close($dbh);
} elseif ($path === 'disp-dob-range') {
$dbh = connect_to_database();
show_table_dob_range($dbh);
mysqli_close($dbh);
} elseif ($path === 'search') {
if (isset($_GET['email']) && !empty($_GET['email'])) {
$dbh = connect_to_database();
if (!($record = search_student($dbh, $_GET['email']))) {
mysqli_close($dbh);
display_failure('Record not found for given E-mail: ' . htmlspecialchars($_GET['email']));
}
show_record($record);
mysqli_close($dbh);
} else {
display_search_form();
}
} else {
display_menu();
echo '<p class="error">Path <code>' . htmlspecialchars($path) . '</code> was not found.</p>';
die();
}
|