Where the First Normal Form deals with atomicity of data, the Second Normal Form (or 2NF) deals with relationships between composite key columns and non-key columns.
英
美
释义
在第二范式中,任何非关键字字段必须依赖整个主关键字。
把海词放在桌面上,查词最方便
触屏版
|
电脑版
©2003 - 2024 海词词典(Dict.cn)
立即下载