摘要:
A Nested Set Implementation in Java and PostgreSQLThis tutorial intends to give the reader:Themotivationsto use the Nested Set structure.Thetheorybehind the Nested Set structure.A possibleschemato implement the Nested Set.A set ofjava classesto allow the Nested Set to be used.Seean alternate impleme 阅读全文
摘要:
This acts provides Nested Set functionality. Nested Set is similiar to Tree, but with the added feature that you can select the children and all of their descendents with a single query. A good use case for this is a threaded post system, where you want to display every reply to a comment without mu 阅读全文
摘要:
Ruby要求:数据表的名字和model的名字必须关联: 1. 表名小写,model名的第一个字母大写; 2. 表名用复数形式(如products),model用单数形式(如Product). 在Rails2.0中,scaffold从核心中移出,转变成插件,使用时,我们需要在所在项目里用下面的命令下载: ruby script/plugin install scaffolding 配置好数据库: drop table if exists products; create table products ( id int not null auto_increment, title varcha.. 阅读全文