title: on delete cascade by default set to on delete restrict in mysql
body: <p>I have two tables (<code>music,music_details</code>).The description of the tables has mentioned bellow</p>
  
  <p>music:</p>
  
  <pre><code>music | CREATE TABLE `music` (
  `music_id` int(11) NOT NULL AUTO_INCREMENT,
  `movie_name` varchar(100) DEFAULT NULL,
  `movie_image` varchar(100) DEFAULT NULL,
  `music_director` varchar(150) DEFAULT NULL,
  `cast` varchar(150) DEFAULT NULL,
  PRIMARY KEY (`music_id`)
  ENGINE=InnoDB DEFAULT CHARSET=latin1 |
  </code></pre>
  
  <p>music_details:</p>
  
  <pre><code>music_details | CREATE TABLE `music_details` (
  `music_id` int(11) DEFAULT NULL,
  `songtitle` varchar(150) DEFAULT NULL,
  `duration` time DEFAULT NULL,
  `artist` varchar(100) DEFAULT NULL,
  `lyricist` varchar(100) DEFAULT NULL,
  `status` varchar(50) DEFAULT NULL,
  KEY `music_id` (`music_id`),
  CONSTRAINT `music_details_ibfk_1` FOREIGN KEY (`music_id`) REFERENCES `music` (`music_id`) on delete cascade on update cascade
  ENGINE=InnoDB DEFAULT CHARSET=latin1 |
  </code></pre>
  
  <p>now my problem is <code>'on delete cascade'</code> is working fine only at that instance,after some time it set to default(<code>on delete restrict</code>).what is the problem.</p>