Slava Rozhnev

$query = $db->prepare(
         "SELECT * FROM users WHERE
         `login`=:login AND
         `password`=:password"
      );

$result = mysqli_query($link, "SELECT acc_get_current_balance('@account_id')  AS current_balance");

while ($row = mysqli_fetch_assoc($result))  {
    echo "Current Balance : {$row['current_balance']} <br>";
}

create table tasks (
	id int  unsigned primary key auto_increment,
  	parent_id int unsigned,
  	user_id int unsigned,
  	status enum('open','closed'),
  	index (parent_id)
);

with recursive free_icons (id) as (
	select 1 
	union all
	select id+1 from free_icons where id <= 40
)
select * from free_icons
where not exists (
	select icon_id from icons where icon_id = free_icons.id
)
limit 1;

select icons.icon_id + 1
from icons
left join icons as next_icon on icons.icon_id + 1 = next_icon.icon_id
where next_icon.icon_id is null and icons.icon_id between 2 and 40
limit 1;

create table users (
	id int primary key auto_increment
);

create table books (
	id int primary key auto_increment,
  	created timestamp,
  	index(created)
);

create table read_books (
	user_id int,
  	book_id int,
  	primary key (user_id, book_id)
);

select * from books
where UNIX_TIMESTAMP() - created < 600 and 
	not exists (
		select book_id 
	  	from read_books 
	  	where read_books.book_id = books.id and read_books.user_id = :user_id 
	)
limit 1;

<?php

$update = 'UPDATE `bes` 
			SET 
				`many` = IF (`many` >= :cena, `many` - :cena, `many`),
				`activation` =  IF (`many` >= :cena, 1, 0)
			WHERE `activation` = 1';

$stmt = $pdo->prepare($update);
$stmt->execute([':cena'=>3]);

SELECT user_id
FROM some_table 
WHERE num IN (878, 925, 242)
GROUP BY user_id
HAVING COUNT(DISTINCT num) = 3 -- 3 количество вариантов
;

SELECT some_table.user_id
FROM some_table 
JOIN some_table st1 ON st1.user_id = some_table.user_id AND st1.num = 925
JOIN some_table st2 ON st2.user_id = some_table.user_id AND st2.num = 242
WHERE some_table.num = 878
;

SELECT user_id, GROUP_CONCAT(DISTINCT num ORDER BY num)
FROM some_table 
WHERE num IN (878,925,242)
GROUP BY user_id
HAVING GROUP_CONCAT(DISTINCT num) = '242,878,925'
;

<?php
$sql = "SELECT id  FROM chatsystem WHERE user1 = ? or user2 = ?";
$stmt = mysqli_stmt_init($connect);

mysqli_stmt_prepare($stmt, $sql);

mysqli_stmt_bind_param($stmt, "ss", $username, $username);
mysqli_stmt_execute($stmt);

$resultData = mysqli_stmt_get_result($stmt);
mysqli_stmt_close($stmt);

 
while ($row = mysqli_fetch_assoc($resultData)) {
	var_export($row);
}

SET @t = '528223,528224';

SELECT * FROM t 
WHERE FIND_IN_SET (t.id, @t );

INSERT INTO aqf_news (
    `title_az`, `date`,  `short_text_az`, `full_text_az`, `category_id`, `gallery`, `gallery_narative_az`, `video1`, `show_slider`, `info_source`
) VALUES (
    'test', NOW(), 'short_text_az', 'full_text_az', 'category_id', 'gallery', 'gallery_narative_az', 'video1', COALESCE(show_slider, 0), 'info_source'
)

select 
	* ,
	case 
		when role = 'boss' then 3
		when role = 'admin' then 2
		else 1
	end as weight
from gamers order by weight desc;

select * 
from gamers 
order by role = 'boss' desc, role = 'admin' desc;

update users_match
set usr2 = case
	when usr1 = 1 then 5
	when usr1 = 2 then 6
	when usr1 = 3 then 7
	else usr2
end;