我的"ON DELETE CASCADE"无效 [英] My 'ON DELETE CASCADE ' does not work

问题描述

我有3个表:lt_hdefaults，lt_hperiods和lt_hrules.在lt_hdefaults中，特定年份的属性有一行.在lt_hperiods表中，可能有多个期间，称为季节.在lt_hrules表中，每个期间可能有多个规则.现在，我无法进行的工作:当用户从lt_hdefaults删除记录时，应该从lt_hperiods和lt_hrules表中删除与删除的记录相关的其他数据.我正在尝试通过使用

I have got 3 tables: lt_hdefaults, lt_hperiods and lt_hrules. In lt_hdefaults, there is one row for a property for a particular year. In the lt_hperiods table, there could be more than one period, call them seasons. In the lt_hrules table, there could be more than one rule for each period. Now, what I could not make work: when the user deletes a record from lt_hdefaults, other data related to the deleted record should be removed from lt_hperiods and lt_hrules table. I am trying to achieve this by using

FOREIGN KEY (lt_year,lt_id) REFERENCES lt_hdefaults(lt_year,lt_id) ON DELETE CASCADE

但是，它不起作用.我知道它看起来很长，但不是很复杂.如果有人有任何想法，我将不胜感激.我知道如何使用mysql，但是我不是这方面的专家.非常感谢.

However, it does not work. I know it looks long but it's not very complicated. If anyone has any idea, I would appreciate it. I know how to use mysql however I am not an expert on that. Thanks very much.

以下示例:

CREATE TABLE IF NOT EXISTS lt_hdefaults (
  lt_year year(4) NOT NULL DEFAULT '0000',
  lt_id int(255) NOT NULL DEFAULT '0',
  period_name varchar(45) NOT NULL DEFAULT 'Default',
  min_stay int(10) NOT NULL DEFAULT '1',
  max_stay int(10) NOT NULL,
  weekly_rate float(10,2) NOT NULL,
  nightly_rate float(10,2) NOT NULL,
  PRIMARY KEY (lt_year,lt_id)
) ENGINE=MyISAM DEFAULT CHARSET=latin1;    

CREATE TABLE IF NOT EXISTS lt_hperiods (
  period_id int(255) NOT NULL ,
  lt_id int(255) NOT NULL,
  lt_year year(4) NOT NULL DEFAULT '0000',
  period_name varchar(45) NOT NULL,
  min_stay int(10) NOT NULL,
  max_stay int(10) NOT NULL,
  fromDate date NOT NULL,
  toDate date NOT NULL,
  weekly_rate float(10,2) DEFAULT NULL,
  nightly_rate float(10,2) NOT NULL,
  arriveDepartDays varchar(150) DEFAULT 'sunday,monday,tuesday,wednesday,thursday,friday,saturday',
  noArriveDepartDays varchar(150) DEFAULT NULL,
  PRIMARY KEY (period_id),
  FOREIGN KEY (lt_year,lt_id) REFERENCES lt_hdefaults(lt_year,lt_id) ON DELETE CASCADE
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=107 ;    

CREATE TABLE IF NOT EXISTS lt_hrules (
  period_id int(255) NOT NULL,
  lt_id int(255) NOT NULL,
  lt_year year(4) NOT NULL DEFAULT '0000',
  rule_name varchar(45) NOT NULL,
  night_of_stay int(10) NOT NULL,
  fixed_rate float(10,2) NOT NULL,
  PRIMARY KEY (period_id,lt_id,night_of_stay),
  FOREIGN KEY (period_id) REFERENCES lt_hperiods(period_id) ON DELETE CASCADE
) ENGINE=MyISAM DEFAULT CHARSET=latin1;    

INSERT INTO lt_hdefaults (lt_year, lt_id, period_name, min_stay, max_stay, weekly_rate, nightly_rate, min_guests, max_guests, surchargeAboveGuests, chargePerGuestFee, bondFee, cleaningFee, bookingServiceFee) VALUES
(2010, 2, 'Default', 0, 0, 1200.00, 171.43, 2, 5, 6, 85.00, 1000.00, 120.00, 0.00),
(2010, 3, 'Default', 0, 0, 1300.00, 185.71, 2, 5, 6, 44.00, 1000.00, 120.00, 0.00);

INSERT INTO lt_hperiods (period_id, lt_id, lt_year, period_name, min_stay, max_stay, fromDate, toDate, weekly_rate, nightly_rate, arriveDepartDays, noArriveDepartDays) VALUES
(105, 3, 2010, 'winter', 2, 66, '2010-12-22', '2011-01-15', 1500.00, 214.29, 'Monday,Tuesday,Wednesday,Thursday', 'Friday,Saturday,Sunday'),
(106, 3, 2010, 'summer', 2, 77, '2011-01-14', '2011-01-28', 4000.00, 571.43, 'Monday,Tuesday,Wednesday,Thursday,Friday,Saturday', 'Sunday');

INSERT INTO lt_hrules (period_id, lt_id, lt_year, rule_name, night_of_stay, fixed_rate) VALUES
(106, 3, 2010, 'r2', 2, 222.00),
(106, 3, 2010, 'r1', 1, 111.00),
(105, 3, 2010, 'r2', 2, 222.00),
(105, 3, 2010, 'r1', 1, 111.00);

推荐答案

ENGINE=MyISAM<-MyISAM不支持任何类型的外键.请改用InnoDB.

ENGINE=MyISAM <-- MyISAM doesn't support any kind of foreign keys. Use InnoDB instead.

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