2020年4月

有一个日志表，记录每日(date)不同类型(datatype) 数据值 格式如下

mysql> select * from userlog;

+-----+------------+----------+-----------+--------+
| uid | date       | datatype | datavalue | logger |
+-----+------------+----------+-----------+--------+
|   4 | 2020-03-03 |        1 |        83 |      2 |
|   4 | 2020-04-04 |        1 |        82 |      1 |
|   5 | 2020-03-03 |        1 |        83 |      2 |
|   6 | 2020-03-03 |        1 |        70 |      3 |
|   6 | 2020-04-04 |        5 |        23 |      3 |
|   6 | 2020-04-04 |        6 |        20 |      3 |
|   6 | 2020-04-04 |        7 |        37 |      3 |
|   6 | 2020-04-04 |       10 |        38 |      3 |
+-----+------------+----------+-----------+--------+
23 rows in set (0.00 sec)

我需要列出各项数据的最新状态时，并用了 group by 和 order by , 发现sql脚本并未如我期望地展示数据

mysql> SELECT * FROM userlog WHERE uid = 4 GROUP BY datatype ORDER BY date DESC;

+-----+------------+----------+-----------+--------+
| uid | date       | datatype | datavalue | logger |
+-----+------------+----------+-----------+--------+
|   4 | 2020-03-03 |        1 |        83 |      2 |
+-----+------------+----------+-----------+--------+
1 row in set (0.00 sec)

原因很好理解，处理的顺序是 先按自然顺序 group 了，才对结果 date 做 order DESC;

- 阅读剩余部分 -

php代码，添加到输出的html末尾

<?php
if(date("Y-m-d")=='2020-04-04'){
?>
<style type="text/css">
    <!--
    html {
        filter: progid:DXImageTransform.Microsoft.BasicImage(grayscale=1);
        -webkit-filter: grayscale(100%);
    }
    -->
</style>
<?php
}
?>

也可以手动css文件头加这行（活动结束后手动撤下）

html {
        filter: progid:DXImageTransform.Microsoft.BasicImage(grayscale=1);
        -webkit-filter: grayscale(100%);
    }