Не указано, какая используется СУБД, ниже запросы подойдут для Postgresql: 1. select article.id from article where article.text like '%beta%' or '%4%' 2. select article.id from article where comments.text is NULL and article_comment_association.article_id=article.id and article_comment_association.сomment_id=comments.id 3. select users.name from users where users.id=article.user_id and article_comment_association.article_id=article.id and article_comment_association.сomment_id=comments.id 4. SELECT article.id, COUNT(comments.id) AS "CNT" from article, comments where article_comment_association.article_id=article.id and article_comment_association.сomment_id=comments.id
Не указано, какая используется СУБД, ниже запросы подойдут для Postgresql: 1. select article.id from article where article.text like '%beta%' or '%4%' 2. select article.id from article where comments.text is NULL and article_comment_association.article_id=article.id and article_comment_association.сomment_id=comments.id 3. select users.name from users where users.id=article.user_id and article_comment_association.article_id=article.id and article_comment_association.сomment_id=comments.id 4. SELECT article.id, COUNT(comments.id) AS "CNT" from article, comments where article_comment_association.article_id=article.id and article_comment_association.сomment_id=comments.id
Ложь - FALSE - действие неверное и его не нужно выполнять