MySQL如果不存在则创建触发器？

Question

SELECT trigger_schema, trigger_name from information_schema.triggers;

+------------------------+------------------+
| trigger_schema         | trigger_name     |
+------------------------+------------------+
| tv_client1             | public_id        |
+------------------------+------------------+

我想为tv_client2添加一个现有的触发器public_id。 如果不存在，如何创建触发器？

最终结果应为：

SELECT trigger_schema, trigger_name from information_schema.triggers;

+------------------------+------------------+
| trigger_schema         | trigger_name     |
+------------------------+------------------+
| tv_client1             | public_id        |
+------------------------+------------------+
| tv_client2             | public_id        |
+------------------------+------------------+

Answer 1

查询SELECT trigger_schema, trigger_name from information_schema.triggers;显示数据库名称和触发器名称。在您的情况下，public_id数据库中已创建tv_client1触发器。如果您希望tv_client2数据库中存在相同的触发器，那么您也可以对CREATE TRIGGER public_id ...数据库执行相同的tv_client2代码，然后将information_schema.triggers反映出来。