我是新手来触发。我试图通过以下链接创建一个触发器 - http://www.postgresqltutorial.com/creating-first-trigger-postgresql/
。但它给出了一些错误。代码块和错误如下:
代码块>>
CREATE OR REPLACE FUNCTION log_last_name_changes()
RETURNS trigger AS
$BODY$
BEGIN
IF NEW.last_name <> OLD.last_name THEN
INSERT INTO employee_audits(employee_id,last_name,changed_on)
VALUES(OLD.id,OLD.last_name,now());
END IF;
RETURN NEW;
END;
$BODY$
而错误>>
ERROR: no language specified
SQL state: 42P13
有人可以帮我吗?
试试这种方式:
CREATE OR REPLACE FUNCTION log_last_name_changes()
RETURNS trigger AS
$BODY$
BEGIN
IF NEW.last_name <> OLD.last_name THEN
INSERT INTO employee_audits(employee_id,last_name,changed_on)
VALUES(OLD.id,OLD.last_name,now());
END IF;
RETURN NEW;
END;
$BODY$
LANGUAGE plpgsql VOLATILE -- Says the function is implemented in the plpgsql language; VOLATILE says the function has side effects.
COST 100; -- Estimated execution cost of the function.