我有树表news_files，files和news
id name
1 valodik
2 gugushik
news_files
id news_id file_id
1 1 5
2 1 6
3 2 9
files
id file_path
5 /opt/storage/
6 /opt/storage/
9 /opt/storage/
trigger在news_files上创建了DELIMITER //
CREATE TRIGGER after_delete_files AFTER DELETE ON news_files
FOR EACH ROW
BEGIN
DELETE FROM files WHERE id=old.file_id;
END;//
DELIMITER ;
news我要删除表files中的数据，它会自动删除news_files.news_id表中的行，news.id被约束级联到delete from news where id = 1;
例子
connect()自动删除表文件中的两行。