ITPub博客

http://blog.csdn.net/u011415782/article/details/78505422https://www.jianshu.com/p/fd09644e91adhttp://tieba.baidu.com/p/4730955412

Building a nested hierarchy of JSON in a relational DBhttps://lakshminp.com/building-nested-hierarchy-json-relational-db其中，不要coalesce点击(此处)折叠或打开SELECT id, name, COALESCE(get_children(id), '[]') as children from genres ...

http://www.cnblogs.com/pigtail/archive/2012/03/09/2387486.html让我们总结一下：1、只要“||”前面为false，无论“||”后面是true还是false，结果都返回“||”后面的值。2、只要“||”前面为true，无论“||”后面是true还是false，结果都返回“||”前面的值。3、只要“&&”前面是false，无论“&&”后面...

http://www.cnblogs.com/kakayang/p/6478069.html