Coding Horrors

Coding
Horrors
A Horror Film Fan’s Guide to
PHP Coding Nightmares

Coding Horrors – Friday the 13th

// 3 month appointments
$date_to = date('d/m/Y');
$date_from = date("d/m/Y", strtotime(" +3 months"));
$get = "select * from appointments where date between '$date_from' and '$date_to'";
$get_connect = mysqli_query($con2, $get);
$get_rows = mysqli_num_rows($get_connect);

mysql> select * from appointments;
+----+-----------+------------------------+
| id | date | appointment |
+----+-----------+------------------------+
| 1 | 2/1/2018 | PHPNW January meetup |
| 2 | 6/2/2018 | PHPNW February Meetup |
| 3 | 6/3/2018 | PHPNW March Meetup |
| 4 | 3/4/2018 | PHPNW April Meetup |
| 5 | 1/5/2018 | PHPNW May Meetup |
| 6 | 5/6/2018 | PHPNW June Meetup |
| 7 | 3/7/2018 | PHPNW July Meetup |
| 8 | 7/8/2018 | PHPNW August Meetup |
| 9 | 4/9/2018 | PHPNW September Meetup |
| 10 | 2/10/2018 | PHPNW October Meetup |
| 11 | 6/11/2018 | PHPNW November Meetup |
| 12 | 4/12/2018 | PHPNW December Meetup |
+----+-----------+------------------------+
12 rows in set (0.01 sec)
mysql> select * from appointments
-> where date between '2/1/2018' and '5/1/2018’;
+----+-----------+------------------------+
| id | date | appointment |
+----+-----------+------------------------+
| 1 | 2/1/2018 | PHPNW January meetup |
| 4 | 3/4/2018 | PHPNW April Meetup |
| 7 | 3/7/2018 | PHPNW July Meetup |
| 9 | 4/9/2018 | PHPNW September Meetup |
| 10 | 2/10/2018 | PHPNW October Meetup |
| 12 | 4/12/2018 | PHPNW December Meetup |
+----+-----------+------------------------+

Coding Horrors – The Ring
$studentArray = array();
$query1 = "SELECT * FROM students ORDER BY name";
$studentList = mysqli_query($conn,$query1)
or die ("cannot query the table1: " . mysqli_error($conn));
while ($student = mysqli_fetch_array($studentList)) {
$studentId = $student['id'];
$courses = array();
$query2 = "SELECT * FROM classes WHERE studentid='$studentId'";
$classList = mysqli_query($conn,$query2)
or die ("cannot query the table2: " . mysqli_error($conn));
while ($class = mysqli_fetch_array($classList)) {
array_push($classes, $class['name']);
}
array_push($studentArray, array($studentId, $student['name'], implode(', ', $classes)));
}

SELECT s.id,
s.name,
group_concat(c.name separator ', ')
FROM students s
LEFT JOIN classes c
ON c.studentid = s.id
GROUP BY s.id,
s.name
ORDER BY s.name;

SELECT s.id,
s.name,
c.name
FROM students s
LEFT JOIN classes c
ON c.studentid = s.id
GROUP BY s.id,
s.name
ORDER BY s.name;

Coding Horrors – The Mummy
$Data = $connection->prepare(
"SELECT * FROM :TableName ORDER BY :OrderByColumn :OrderDirection LIMIT 10 OFFSET :Offset"
);
$Data->bindValue(':TableName', $TableName, PDO::PARAM_STR);
$Data->bindValue(':Offset', $Offset, PDO::PARAM_INT);
$Data->bindValue(':OrderByColumn', $OrderColumn, PDO::PARAM_STR);
$Data->bindValue(':OrderDirection', $OrderDirection, PDO::PARAM_STR);
$Data->execute();

Coding Horrors – Night of the
Living Dead

Living Dead
function getAddressDetails() {
$data->name = 'Mark';
// $data->address = 'mi casa';
// $data->city = 'Manchester';
// $data->country = 'UK';
// return json_encode($data, JSON_UNESCAPED_UNICODE);
return json_encode($data);
}

Living Dead
function getAddressDetails() {
$data->name = 'Mark’;
return json_encode($data);
}
git commit -m "Remove address, which is now accessed through a separate API call"

Living Dead
function addValues($a, $b, $options) {
$sum = 0;
return $a + $b;
}

Living Dead
function squareIt($bar) {
return $bar ** 2;
$bar *= $bar;
return $bar;
}

Coding Horrors – The Ring (US
Remake)

Coding Horrors – The Ring (US
Remake)
DRY
Don’t Repeat Yourself

Coding Horrors – Chain Letter

mysql> select * from users;
+----+----------+----------------------------------+-----------+
| id | username | password | followers |
+----+----------+----------------------------------+-----------+
| 1 | Shirley | 5f4dcc3b5aa765d61d8327deb882cf99 | 8,6,10 |
| 2 | Deborah | d1133275ee2118be63a577af759fc052 | 4 |
| 3 | Julie | 25d55ad283aa400af464c76d713c07ad | 4,5 |
| 4 | Jane | 4297f44b13955235245b2497399d7a93 | 3,5 |
| 5 | Jennifer | d8578edf8458ce06fbc5bb76a58c5ca4 | 3,4 |
| 6 | Alison | 827ccb0eea8a706c4c34a16891f84e7b | 9,1 |
| 7 | Philipa | 8621ffdbc5698829397d97767ac13db3 | NULL |
| 8 | Sue | acc6f2779b808637d04c71e3d8360eeb | 1 |
| 9 | Annabel | 0d107d09f5bbe40cade3de5c71e9e9b7 | 6 |
| 10 | Cathy | 5badcaf789d3d1d09794d8f021f40f0e | 3,1 |
+----+----------+----------------------------------+-----------+

mysql> select * from users where followers like '%1%';
+----+----------+----------------------------------+-----------+
| id | username | password | followers |
+----+----------+----------------------------------+-----------+
| 1 | Shirley | 5f4dcc3b5aa765d61d8327deb882cf99 | 8,6,10 |
+----+----------+----------------------------------+-----------+

mysql> select * from users where followers like '%,1,%';
Empty set (0.00 sec)
mysql> select * from users
-> where followers = '1' or followers like '1,%' or followers like '%,1,%' or followers like '%,1';
+----+----------+----------------------------------+---------+
| id | username | password | friends |
+----+----------+----------------------------------+---------+
+----+----------+----------------------------------+---------+

mysql> select * from users where find_in_set(1,friends);
+----+----------+----------------------------------+---------+
| id | username | password | friends |
+----+----------+----------------------------------+---------+
+----+----------+----------------------------------+---------+

Returns

Returns
$q = "SELECT id, name FROM test WHERE name like '%:foo%'";
$s = "carrot";
$sth = $dbh->prepare($q);
$sth->bindParam(':foo', $s);
$sth->execute();

Returns
$q = "SELECT id, name FROM test WHERE name like :foo";
$s = "carrot";
$s = "%{$s}%";
$sth->bindParam(':foo', $s);
$sth->execute();

Returns
$q = "SELECT * FROM posts WHERE post_title LIKE :q OR post_text LIKE :q";
$s = "carrot";
$s = "%{$s}%";
$sth->bindParam(':q', $s);
$sth->execute();

Returns
$q = "SELECT * FROM posts WHERE post_title LIKE :q1 OR post_text LIKE :q2";
$s = "carrot";
$s = "%{$s}%";
$sth->bindParam(':q1', $s);
$sth->bindParam(':q2', $s);
$sth->execute();

Coding Horrors – Halloween
function monthList() {
$startDate = new DateTime();
$endDate = (clone $startDate)
->add(new DateInterval('P1Y'));
$dateRange = new DatePeriod($startDate, new DateInterval('P1M'), $endDate);
foreach($dateRange as $date) {
yield $date;
}
}
foreach(monthList() as $date) {
echo $date->format("M Y") . PHP_EOL;
}

Jan 2018
Feb 2018
Mar 2018
Apr 2018
May 2018
Jun 2018
Jul 2018
Aug 2018
Sep 2018
Oct 2018
Nov 2018
Dec 2018
Jan 2018
Mar 2018
Apr 2018
May 2018
Jun 2018
Jul 2018
Aug 2018
Sep 2018
Oct 2018
Nov 2018
Dec 2018
Jan 2019

Coding Horrors – Alien
if (strpos(" " . $fileURL, "s3://") >= 1) {
// Do something
}

Coding Horrors – Alien
if (strpos($fileURL, "s3://") !== false) {
// Do something
}

Coding Horrors – Se7en
$calendar = [
01 => 'January',
02 => 'February',
03 => 'March',
04 => 'April',
05 => 'May',
06 => 'June',
07 => 'July',
08 => 'August',
09 => 'September',
10 => 'October',
11 => 'November',
12 => 'December',
];

1 => January
2 => February
3 => March
4 => April
5 => May
6 => June
7 => July
0 => September
10 => October
11 => November
12 => December

$calendar = [
1 => 'January',
2 => 'February',
3 => 'March',
4 => 'April',
5 => 'May',
6 => 'June',
7 => 'July',
8 => 'August',
9 => 'September',
10 => 'October',
11 => 'November',
12 => 'December',
];

Coding Horrors – Pan’s Labyrinth

public function __construct(
MagentoFrameworkModelContext $context,
MagentoFrameworkViewDesignInterface $design,
MagentoFrameworkRegistry $registry,
MagentoStoreModelAppEmulation $appEmulation,
MagentoStoreModelStoreManagerInterface $storeManager,
MagentoFrameworkAppRequestInterface $request,
MagentoNewsletterModelTemplateFilter $filter,
MagentoFrameworkAppConfigScopeConfigInterface $scopeConfig,
MagentoNewsletterModelTemplateFactory $templateFactory,
MagentoFrameworkFilterFilterManager $filterManager,
array $data = []
) {
parent::__construct($context, $design, $registry, $appEmulation, $storeManager, $data);
$this->_storeManager = $storeManager;
$this->_request = $request;
$this->_filter = $filter;
$this->_scopeConfig = $scopeConfig;
$this->_templateFactory = $templateFactory;
$this->_filterManager = $filterManager;
}

The ideal number of arguments for a function is zero (niladic). Next
comes one (monadic) followed closely by two (dyadic). Three
arguments (triadic) should be avoided where possible. More than three
(polyadic) requires very special justification—and then shouldn't be
used anyway.
Bob Martin – “Clean Code”

Coding Horrors – Scream
$sql = "SELECT MAX(id) AS max_page FROM videos";
$result = @$conn->query($sql);
$row = @mysql_fetch_array($result);
echo $row["max_page"];

@dns_get_record();
dns_get_record();

Warning: dns_get_record() expects at least 1 parameter, 0 given in
%filename% on %line%

set_error_handler(function($errno, $errstr, $errfile, $errline, array $errcontext) {
if (error_reporting() === 0) {
// error was suppressed with the @-operator
throw new ErrorException(
'WHY ARE YOU SUPPRESSING ERRORS RATHER THAN HANDLING THEM!'
);
// return false;
}
throw new ErrorException($errstr, 0, $errno, $errfile, $errline);
});

try {
@dns_get_record();
} catch (ErrorException $e) {
echo 'EXCEPTION: ', $e->getMessage(), PHP_EOL;
}
try {
dns_get_record();
} catch (ErrorException $e) {
echo 'EXCEPTION: ', $e->getMessage(), PHP_EOL;
}

EXCEPTION: WHY ARE YOU SUPPRESSING ERRORS RATHER THAN HANDLING THEM?
EXCEPTION: dns_get_record() expects at least 1 parameter, 0 given

• Scream
• PECL Extensions
• Disables the @ error control operator so that all errors are reported.
ini_set('scream.enabled', true);

Coding Horrors – Dawn of the Dead

Coding Horrors – Dawn of the Dead
/**
* Convert a date from PHP to Excel
*
* @param mixed $dateValue unix timestamp or datetime object
* @param string $timezone Optional timezone name for adjustment from UTC
* @return mixed Excel date/time value
**/
public function PHPToExcel(DateTimeImmutable $dateValue, DateTimeZone $timezone = null) {
// Do stuff
}

Who am I?
Mark Baker
Coordinator and Developer of:
Open Source PHPOffice library
PHPExcel (PHPSpreadsheet), PHPWord, PHPPresentation (formerly PHPPowerPoint), PHPProject, PHPVisio
Minor contributor to PHP core
@Mark_Baker
https://github.com/MarkBaker
http://uk.linkedin.com/pub/mark-baker/b/572/171
http://markbakeruk.net

Coding Horrors

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