mysql - Modify the isbn data of the database so that if the isbn encoding is normal, it will not change. If it exceeds 13 digits, the first 13 digits will be taken directly. How should I write the sql statement?
(www.sf.gg) is China's leading developer technology community. We hope to provide a pure, high-quality technical exchange platform for programming enthusiasts, learn, communicate and grow with developers, and create an era for developers!
ringa_lee 2017-05-18 10:50:27 0 1 456
javascript面向对象 - JavaScript extend方法的最后修改superClass.prototype.constructor
该问题困扰我好久了。 原书《JavaScript设计模式》,ISBN: 9787115191281。代码在42页下方。 书中写的extend函数如下: {代码...} 问题是最后3行这个if语句有什么用呢?书上说,即使父类是Object也可以正常继承,...
阿神 2017-04-10 15:06:12 0 3 472
php - CodeIgniter执行删除作为外键的记录遇到问题
假设两个表desc如下: book (isbn PK,authorid int FK) author (authorid PK,name varchar(10)) 现在有两条记录 book 1111, 001 author 001, orz 在未设置的情况下,如果想删除author记录,是不行的。 现在,使用...
阿神 2017-04-10 15:03:55 0 0 201