Question

我有一个名为“ supported_languages”的表，如下所示：

-----------------------------------------------------------
language_ref   |   language _name   |   language_active   |
-----------------------------------------------------------
en             |    English         |        Y            |
-----------------------------------------------------------
es             |    Espanol         |        Y            |
-----------------------------------------------------------
fr             |    Francias        |        Y            |
-----------------------------------------------------------
he             |    hebrew          |       NULL          |
-----------------------------------------------------------

我想创建一个查询，该查询将仅将英语设置为有效。仅当以下三种语言-en，es，fr处于活动状态（Y）并且“ he”语言为空时（与提供的表格相同）。仅在这种情况下-将“ language_active”下的所有内容更改为N，并使英语成为唯一有效的语言。

有什么帮助吗？

谢谢！

Answer 1

您需要将类似的内容放入更新触发器中。

if exists (select * from supported_languages where language_ref = 'en' and language_active = 'Y')
    and exists (select * from supported_languages where language_ref = 'es' and language_active = 'Y')
    and exists (select * from supported_languages where language_ref = 'fr' and language_active = 'Y')
    and exists (select * from supported_languages where language_ref = 'he' and language_active = 'N')
    update supported_languages set language_active = 'N' 
where language_ref = 'es' or language_ref = 'fr'

mysql替换成if语句

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