Question

以下查询按预期工作并向我显示我的触发器。

SELECT TRIGGER_SCHEMA, EVENT_OBJECT_TABLE,
IF(EVENT_MANIPULATION = 'UPDATE' AND ACTION_TIMING='BEFORE', TRIGGER_NAME, '') AS BEFORE_UPDATE,
IF(EVENT_MANIPULATION = 'UPDATE' AND ACTION_TIMING = 'AFTER', TRIGGER_NAME, '') AS AFTER_UPDATE,
IF(EVENT_MANIPULATION = 'INSERT' AND ACTION_TIMING='BEFORE', TRIGGER_NAME, '') AS BEFORE_INSERT,
IF(EVENT_MANIPULATION = 'INSERT' AND ACTION_TIMING = 'AFTER', TRIGGER_NAME, '') AS AFTER_INSERT,
IF(EVENT_MANIPULATION = 'DELETE' AND ACTION_TIMING='BEFORE', TRIGGER_NAME, '') AS BEFORE_DELETE,
IF(EVENT_MANIPULATION = 'DELETE' AND ACTION_TIMING = 'AFTER', TRIGGER_NAME, '') AS AFTER_DELETE
from information_schema.triggers ;

问题是如果我有3个AFTER触发器，它会显示在3个单独的行上。如何在同一行显示所有三个？我尝试使用TRIGGER_SCHEMA，EVENT_OBJECT_TABLE进行分组 - 但它显示了预期触发器名称的空白值。

Answer 1

尝试做

COALESCE（IF（....））作为FinalColumn

可能会有多个插入/更新/删除触发器（或级联结果）影响您的结果。

自我加入以避免分组

1 个答案: