如何为两种情况设置“ORDER BY”？

Question

在mysql中，我需要为两种情况设置“ORDER BY”：name或mod_1，具体取决于用户在组合框中选择的内容。我的疑问是：

SELECT
    name,
    SUM(IF(mod = 1, 1, 0)) AS mod_1,
    SUM(IF(mod = 2, 1, 0)) AS mod_2,
    SUM(IF(mod = 3, 1, 0)) AS mod_3
FROM
    DW_RM_Log
WHERE
    ...
ORDER BY
    name (or mod_1 DESC)

是否可以在mysql中执行此操作或者我需要在php中编写代码？或两者兼而有之？

Answer 1

厌倦了为你做这件事：

$q = "SELECT
    name,
    SUM(IF(mod = 1, 1, 0)) AS mod_1,
    SUM(IF(mod = 2, 1, 0)) AS mod_2,
    SUM(IF(mod = 3, 1, 0)) AS mod_3
FROM
    DW_RM_Log
WHERE
    ...
ORDER BY ";

if ($x) {
    $q .= "name DESC";
} else {
    $q .= "mod_1 DESC";
}
 //run $q!