SELECT *
FROM
(
SELECT t1.*,
RANK() OVER(ORDER BY cnt DESC PARTITION BY city) AS rn2
FROM
(
SELECT city, hobby, COUNT(hobby) AS cnt
FROM table
GROUP BY city, hobby
) AS t1
ORDER BY city, cnt DESC
) AS t1
WHERE rn2=1SELECT user1, user2, cnt
FROM
(
SELECT t3.name AS user1,
t4.name AS user2,
COUNT(*) AS cnt
FROM users_groups AS t1
INNER JOIN users_groups AS t2
ON t1.user_id<t2.user_id
AND t1.group_id=t2.group_id
LEFT JOIN users AS t3
ON t1.user_id=t3.id
LEFT JOIN users AS t4
ON t2.user_id=t4.id
GROUP BY t1.user_id, t2.user_id, t3.name, t4.name
) AS t1
ORDER BY cnt DESC
LIMIT 0,1SELECT Content_id
FROM table
WHERE t.Tag_id = 'aa'
EXCEPT
SELECT Content_id
FROM table
WHERE t.Tag_id = 'bb'SELECT Content_id
FROM table AS t
WHERE t.Tag_id = 'aa'
AND t.Tag_id NOT IN
(
SELECT Content_id
FROM table
WHERE t.Tag_id = 'bb'
)SELECT *
FROM questions
WHERE userName='YourOwnSenpaie'
/*
* - означает, что выбираем все поля (имя, фамилию, ник, e-mail и т д)
questions - название таблицы, хранящей вопросы
WHERE userName='YourOwnSenpaie' - условие, означающее, что выбирать нужно только ваши вопросы, а не чужие
*/SELECT *
FROM Nakladnaya
INNER JOIN Zakaz
ON Nakladnaya.ZakazNomer=Zakaz.Nomer
INNER JOIN Product
ON Nakladnaya.ProductId=Product.ID