触发动态知道事件类型

Question

对于在 INSERT 或 UPDATE 之前发生的触发器，我有大部分相同的代码， 而不是创建 2 个触发器，是否有任何方法可以知道触发器内动态发生的事件类型？

示例：

CREATE OR REPLACE FUNCTION UpsertClientLog() RETURNS TRIGGER AS $$
DECLARE action_type VARCHAR(255);
BEGIN
  IF (event == 'INSERT') THEN
    action_type = 'Create'
  ELSE 
    action_type = 'Update'
  END IF;

  -- Same code from here on out ..
END;
$$ LANGUAGE plpgsql;

CREATE TRIGGER UPSERT_CLIENT_LOG BEFORE INSERT OR UPDATE ON client
  FOR EACH ROW EXECUTE PROCEDURE UpsertClientLog();

Answer 1

您可以使用 special variable TO_OP:

TG_OP

Data type text; a string of INSERT, UPDATE, DELETE, or TRUNCATE telling for which operation the trigger was fired.