有什么方法可以在 MySQL CASE 语句中对案例进行分组吗?

Is there any way for grouping cases in MySQL CASE statements?

是否有像 PHP switch 中那样编写 MySQL CASE 语句的缩写形式?例如,如果我有:

SELECT
    CASE Type
        WHEN 1 THEN "A"
        WHEN 5 THEN "B"
        WHEN 10 THEN "B"
        WHEN 20 THEN "B"
        WHEN 30 THEN "B"
        WHEN 300 THEN "C"
        ELSE "-"
    END TypeDesc

在PHP语法中我们可以简单地写成:

switch ($Type) {
    case 1: $TypeDesc = 'A'; break; 
    case 5:
    case 10:
    case 20:
    case 30: $TypeDesc = 'B'; break; 
    case 300: $TypeDesc = 'C'; break;
    default: $TypeDesc = '-'; }

我试过了:

WHEN 5 OR 10 OR 20 OR 30 THEN "B"

WHEN IN(5, 10, 20, 30) THEN "B"

还有这两个:

WHEN 5
WHEN 10
WHEN 20
WHEN 30 THEN "B"

WHEN 5 THEN
WHEN 10 THEN
WHEN 20 THEN
WHEN 30 THEN "B"

但是我得到不正确的结果或错误!

使用

case when <condition>

而不是

case <variable> when <value>

像这样

SELECT
    CASE WHEN Type = 1 THEN "A"
         WHEN Type < 300 THEN "B"
         WHEN Type = 300 THEN "C"
         ELSE "-"
    END TypeDesc