3 задание с июн\ по авг 10
SELECT `user_id`, COUNT(`text`)
FROM `comments`
WHERE `date` BETWEEN '2010-06-01 00:00:00' AND '2010-08-01 00:00:00'
GROUP BY `user_id`


4 задание
SELECT usergroups.id, usergroups.group_name, COUNT(`autor_id`)
FROM `news`, `users`, `usergroups`
WHERE users.user_group=usergroups.id AND news.autor_id=users.user_id GROUP BY group_name


5 задание

15 задание



8 задание
SELECT user_id, COUNT(user_id)
FROM `comments`
WHERE `text` LIKE `%спасибо%`
GROUP BY user_id

11 задание
SELECT usergroups.id, usergroups.group_name, COUNT(user_id)
FROM comments, usergroups, users
WHERE comments.user_id=users.user_id
AND users.user_group = usergroups.id
GROUP BY group_name


12 задание

INSERT INTO  news(autor_id) SELECT users.user_id
FROM users,news
WHERE users.name=news.autor

13 задание
UPDATE news SET news.comm_num = (SELECT COUNT{comments.post_id}
FROM comments
WHERE comments.post_id = news.id}