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 添加现有触发器 public_id。 如果触发器不存在，如何创建？

最终结果应该是:

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 触发器已在 tv_client1 数据库中创建。如果您希望 tv_client2 数据库中存在相同的触发器，则可以针对 tv_client2 数据库执行相同的 CREATE TRIGGER public_id ... 代码，如下所示好吧，同样的内容将反射(reflect)在 information_schema.triggers 中。