这个SQL语法中的错误是什么？

Question

我创建了这个SQL语句：

SELECT * 
    FROM forum_question 
        LEFT JOIN forum_answer ON (
            forum_question.id = forum_answer.question_id) 
    ORDER BY a_datetime DESC GROUP BY forum_question.id;

有谁知道这个问题？ forum_question和forum_answer以及列'id'由by存在。

Answer 1

GROUP BY子句应该在ORDER BY子句之前出现。尝试交换它，

GROUP BY forum_question.id
ORDER BY a_datetime DESC