构造一个查询，使其仅在一天中的某个时间之后显示今天的事件

Question

我有一个问题，就是给学生拉作业。我希望总是显示小于或等于今天日期的所有内容，这很好，但是我如何在PHP或MySQL中添加一个规定，在上午8:30之后显示今天的事件，同时仍然始终显示今天之前的任何内容。

试图阻止学生在上学前看到他们的作业。

        //Get & Display the Homework
    $getTopics = mysql_query("SELECT topicId, categoryId, topicName, assignmentDate FROM forumTopics WHERE categoryId = '".$forumId."' AND hidden = '0' and assignmentDate <= '".$today."' ORDER BY createdDate DESC") or die("Cannot get forum topics: " . mysql_error());

Answer 1

您的SQL是：

SELECT topicId, categoryId, topicName, assignmentDate
FROM forumTopics
WHERE categoryId = '".$forumId."' AND hidden = '0' and assignmentDate <= '".$today."'
ORDER BY createdDate DESC;

今天早上8:30之后才能做这个节目：

SELECT topicId, categoryId, topicName, assignmentDate
FROM forumTopics
WHERE categoryId = '".$forumId."' AND hidden = '0' and
      (assignmentDate < '".$today."' or assigmentDate = '".$today."' and time('".today."') >= '08:30:00'
ORDER BY createdDate DESC;

这是假设您的变量$today同时具有日期和时间。否则，只需使用now()和/或CURDATE()和/或CURTIME()即可。