Slava Rozhnev

Регулярное выражение:
/\/([^\/]+)$/

Но лучше использовать встроенные функции языка (PHP нпример имеет функцию parse_url):

<?php
$url = 'https://www.domain.ru/test-url';

// using preg_match
preg_match('/(\/[^\/]+)$/', $url, $matches);

echo $matches[1].PHP_EOL;


// using parse_url 
echo parse_url($url, PHP_URL_PATH);

PHP parse_url

Можно так:

with objects as (
  select idObject
  from tbl
  where idProperty in (1,4)
  group by idObject
  having  count(distinct idProperty) = 2
) 
select * from tbl join objects using(idObject);

PostgreSQL CTE fiddle

Используем CTE и функцию row_number

with data as (select 
	id,
	a, b, c,
	row_number() over (partition by a,b order by id) rn
from t
) select id,a, b, c from data where rn = 1;

MySQL CTE row_number

<?php
class A
{
	protected $sql = null;
	
	public function setSQL()
    {
        $this->sql = "SELECT * FROM users WHERE id = 123";
        return $this;
    }
	
	public function getSQL()
    {
        return $this->sql;
    }
}

class B extends A
{
    public function addSQL()
    {
        $this->sql .= " AND name = 'Alex'";
		
		return $this;
    }
}
$a = new A();
$b = new B();

echo $b->setSQL()->addSQL()->getSQL();

PHP class test

Уважаемый, Вам нужно изучать основы MySQL. Ваша задача решается одним запросом и 3-мя строками кода.

<?php
  $query = "SELECT  DATE(`time`) `Day`, SUM(`Profit`) `DaylyProfit`
			FROM `history`
			WHERE  `type` = 1 AND `time` > DATE_SUB(CURRENT_DATE, INTERVAL 6 DAY)
			GROUP BY `Day`
			ORDER BY `Day` DESC;";

$result = $mysqli->query($query);

$all = $result -> fetch_all(MYSQLI_ASSOC);


echo json_encode($all);

Test PHP MySQL online

Проблема 2 и 3 решаются элементарно:

update t set
	time_from = LOWER(time_from),
	nullable = IF(nullable is null or nullable = '', 1, nullable)
;

MySQL update fiddle

Информация о колонках содержится в предстфвлении information_schema.columns

SELECT
	*
FROM
	information_schema.columns
WHERE
	table_schema = 'schema_name'
	AND table_name = 'table_name';

PostgreSQL information_schema.columns

например:

create table books (
	ID INT,
  	AUTHOR VARCHAR
);


SELECT
	*
FROM
	information_schema.columns
WHERE	table_name = 'books';

Поробуйте так:

<?php
$otp1start = "2021-11-10";
$otp1end = "2021-11-20";
$now_date = date("Y-m-d");

if ($now_date > $otp1end) {
    echo "Отпуск уже прошел";
} elseif ($now_date >= $otp1start) {
    echo "Сотрудник в отпуске";
} else {
    echo "Отпуск еще не наступил";
}
?>

PHP online test

Начиная с PostgreSQL 13 можно использовать новый функционал FETCH вместо LIMIT :

SELECT AUTHOR
FROM POSSESSION
INNER JOIN BOOKS ON BOOK_ID = BOOKS.ID
WHERE TAKING_DATE > (CURRENT_DATE - INTERVAL '1 year')
GROUP BY AUTHOR
ORDER BY COUNT(AUTHOR) DESC
FETCH FIRST 1 ROWS WITH TIES;

PostgreSQL fetch online

Попробуйте:

SELECT 
	COUNT(DISTINCT CASE WHEN people.gender = 'M' THEN list.id END) AS mens,
	COUNT(DISTINCT CASE WHEN people.gender = 'F' THEN list.id END) AS womens,
	COUNT(DISTINCT CASE WHEN people.gender IS NULL THEN list.id END) AS unknown
FROM ListTable AS list 
LEFT JOIN PeopleTable AS people ON (list.userID = people.id) 
;

MS SQL Fiddle

Я бы предложил такой вариант:

<?php
$board = [
	'a' => [
		'1' => '',
		'2' => '',
		'3' => '',
		'4' => '',
		'5' => '',
		'6' => '',
		'7' => '',
		'8' => '',
	],
	'b' => [
		'1' => 'белый конь',
		'2' => '',
		'3' => '',
		'4' => '',
		'5' => '',
		'6' => '',
		'7' => '',
		'8' => '',
	],
	// ---
	'g' => [
		'1' => '',
		'2' => '',
		'3' => '',
		'4' => '',
		'5' => '',
		'6' => '',
		'7' => '',
		'8' => '',
	],
	'h' => [
		'1' => '',
		'2' => '',
		'3' => '',
		'4' => '',
		'5' => '',
		'6' => '',
		'7' => '',
		'8' => '',
	]
];

// ход конем b1 -> a3
$board['a']['3'] = 'белый конь';
$board['b']['1'] = '';

print_r($board);

PHP chess board

Из базы напрямую можно получить массив:

select 
  office_id,
  json_arrayagg(employee_id) employee_ids
from t 
group by office_id;

MySQL json_arrayagg fiddle

+===========+==============+
| office_id | employee_ids |
+===========+==============+
| 1         | [1, 2]       |
+-----------+--------------+

Если нужно время исполнения скрипта используйте функцию time:

<?php
$start = microtime(TRUE);

sleep(3);

$diff = microtime(TRUE) - $start;

printf('Execution time: %s s', $diff);

PHP time online

const stmt = db.prepare("INSERT INTO users (user_id, user_nick, password) VALUES(?,  ?, ?)");
stmt.run(user_id,  req.body.username, req.body.passwd);
stmt.finalize();

Для следует указать путь к исполняемому файлу:

$path = 'C:\path\to\mysqldump\';
exec("{$path}mysqldump --user={$user} --password={$pass} --host={$host} {$database} --result-file={$dir} 2>&1", $output);

\/([^\/]+)$

PHP code:

<?php
$path = 'D:\domains\99ballov/frontend/web//images/user/76/support/Screenshot_20211020-143428_WhatsApp_1637057308.jpg';

// using preg_match
preg_match('/\/([^\/]+)$/', $path, $matches);

echo $matches[1].PHP_EOL;


// using basename 
echo basename($path).PHP_EOL;

PHP preg_match online