Question

我有4个表：参加者，历史记录，参与者_用户和余额。 Tables History和Attendee_Owes有FK引用Attendees PK。

历史记录包含与会者的所有付款记录。

Attendee_Owes仅为历史记录表中的每位与会者保留最后一条记录。

这两个表的模式是：

sqlite> .schema history
CREATE TABLE HISTORY(
HISTORY_ID INTEGER PRIMARY KEY,
LAST_PAYMENT_DATE VARCHAR NOT NULL,
CURRENT_PAYMENT_DATE VARCHAR NOT NULL,
SUBSIDY VARCHAR(1) NOT NULL,
WEEKLY_PAYMENT REAL NOT NULL,
AMOUNT_PAID REAL NOT NULL,
HISTORY_BALANCE REAL NOT NULL,
HIST_ATTENDEE_ID INTEGER,
FOREIGN KEY(HIST_ATTENDEE_ID) REFERENCES ATTENDEES(ATTENDEE_ID) 
ON DELETE CASCADE 
ON UPDATE CASCADE
);

sqlite> .schema attendee_owes
CREATE TABLE ATTENDEE_OWES(
OWES_ID INTEGER PRIMARY KEY,
ATTENDEE_OWES_BALANCE REAL NOT NULL,
OWES_ATTENDEE_ID INTEGER,
FOREIGN KEY(OWES_ATTENDEE_ID) REFERENCES ATTENDEES(ATTENDEE_ID)
ON DELETE CASCADE 
ON UPDATE CASCADE
);

我的问题是删除历史记录时触发的触发器。

CREATE TRIGGER after_history_delete
AFTER DELETE ON history
BEGIN
   UPDATE ATTENDEE_OWES SET ATTENDEE_OWES_BALANCE = (SELECT HISTORY_BALANCE FROM HISTORY ORDER BY HISTORY_ID DESC LIMIT 1) WHERE OWES_ATTENDEE_ID = HIST_ATTENDEE_ID;
END;

我在UPDATE语句结束时收到错误：没有这样的列：HIST_Attendee_ID

我试过了：

UPDATE ATTENDEE_OWES SET ATTENDEE_OWES_BALANCE = (SELECT HISTORY_BALANCE FROM HISTORY ORDER BY HISTORY_ID DESC LIMIT 1) WHERE OWES_ATTENDEE_ID = HISTORY.HIST_ATTENDEE_ID;

和

UPDATE ATTENDEE_OWES SET ATTENDEE_OWES_BALANCE = (SELECT HISTORY_BALANCE FROM HISTORY ORDER BY HISTORY_ID DESC LIMIT 1) WHERE OWES_ATTENDEE_ID = HISTORY(HIST_ATTENDEE_ID);

但我仍然收到错误，告诉我没有这样的专栏。

我已经尝试过我所知道的一切。任何建议都将不胜感激。

Answer 1

让我们以更方便的方式查看您的SQL：

UPDATE ATTENDEE_OWES SET 
  ATTENDEE_OWES_BALANCE = (
    SELECT HISTORY_BALANCE 
    FROM HISTORY 
    ORDER BY HISTORY_ID DESC LIMIT 1) 
WHERE 
  OWES_ATTENDEE_ID = HIST_ATTENDEE_ID;

我们可以看到OWES_ATTENDEE_ID = HIST_ATTENDEE_ID与表HISTORY未知的最顶层相关。正确的查询必须是：

UPDATE ATTENDEE_OWES SET 
  ATTENDEE_OWES_BALANCE = (
    SELECT HISTORY_BALANCE 
    FROM HISTORY
    WHERE OWES_ATTENDEE_ID = HIST_ATTENDEE_ID
    ORDER BY HISTORY_ID DESC LIMIT 1)

外键列未被识别

1 个答案: