触发触发器时超出堆栈深度限制

Question

我正在尝试构建一个缓慢变化的维度table，它跟踪所有的历史记录。 table 的架构是这样的：

CREATE TABLE test.dim
(id text,
 column1 text,
 column2 text,
 begin_date timestamp without time zone,
 is_current boolean,
 end_date timestamp without time zone)

我定义了一个触发器函数，并在每次插入操作之前触发它：

CREATE OR REPLACE FUNCTION test.slow_change_func()
  RETURNS trigger AS
$BODY$
  DECLARE
    BEGIN
        IF ( NOT EXISTS ( SELECT 1 FROM yang_test.dim
                          WHERE id= NEW.id  
                                AND(column1 = NEW.column1 OR (column1 is null AND NEW.column1 is null))
                                AND (column2 = NEW.column2 OR (column2 is null AND NEW.column2 is null))
                                AND is_current
                          )
            )
        THEN  UPDATE yang_test.dim
               SET (end_date, is_current) = (now(), FALSE)
               WHERE id = NEW.id
                        AND is_current;
               INSERT INTO test.dim (id, column1, column2, begin_date, is_current, end_date)
               VALUES ( NEW.id, NEW.column1, NEW.column2, now(), TRUE, 'infinity'::timestamp );

         END IF;
      RETURN NULL;
    END;
$BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100;





CREATE TRIGGER slow_change_trigger
  BEFORE INSERT
  ON test.dim
  FOR EACH ROW
  EXECUTE PROCEDURE test.slow_change_func();

当我尝试测试它时，

INSERT INTO test.dim (id, column1, column2, begin_date, is_current, end_date)
               VALUES ( 1, 'hello', 'world', now(), TRUE, 'infinity'::timestamp )

它会抛出一个错误：超出堆栈深度限制。看起来函数是运行一个循环。有什么建议吗？

Answer 1

我想我已经弄明白了，这符合我的要求：

CREATE OR REPLACE FUNCTION yang_test.slow_change_func()
  RETURNS trigger AS
$BODY$
  DECLARE
    BEGIN
        IF ( NOT EXISTS ( SELECT 1 FROM yang_test.dim
                          WHERE id= NEW.id  
                                AND(column1 = NEW.column1 OR (column1 is null AND NEW.column1 is null))
                                AND (column2 = NEW.column2 OR (column2 is null AND NEW.column2 is null))
                                AND is_current
                          )
            )
        THEN  UPDATE yang_test.dim
               SET (end_date, is_current) = (now(), FALSE)
               WHERE id = NEW.id
                        AND is_current;
        ELSE RETURN null;


         END IF;
        RETURN NEW;
    END;
$BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100;

触发触发器时超出堆栈深度限制

stack depth limit exceeded when fired a trigger

postgresql

database-trigger