php ORDER BY日期似乎不起作用

Question

我只想显示折扣最新的图书。 Dealstart和Dealend代表了窗口。但是我搞砸了什么。

$sqlCommand = "SELECT id,bookcover FROM booklist WHERE category1='$bookid' OR category2='$bookid' OR category3='$bookid' AND dealstart >= CURDATE() AND dealend is >= CURDATE()";

Answer 1

看起来SQL语句中存在语法错误，删除“是”：

lCommand = "SELECT id,bookcover FROM booklist WHERE category1='$bookid' OR category2='$bookid' OR category3='$bookid' AND dealstart >= CURDATE() AND dealend >= CURDATE()";

如果查询仍无效，请回显“lCommand”并查看其产生的内容，然后尝试针对您的数据库运行该查询。

Answer 2

喜欢这个吗？

$sqlCommand = "SELECT
                   id,
                   bookcover
               FROM
                   booklist
               WHERE
                   category1='$bookid' OR
                   category2='$bookid' OR
                   category3='$bookid' AND
                   dealstart >= CURDATE() AND
                   dealend >= CURDATE()
               ORDER BY
                   dealend DESC";