淘宝网开发人员数据库知识参考手册下载后可任意编辑编写、修订、审核记录编号文档版本修订章节修订原因修订日期修订人11.0全文新建文档2024-9-27胜通22.0补充文档2024-1-6胜通345678910下载后可任意编辑目录第一章 基本元素.....................................................................................................................................6第一节 数据类型.................................................................................................................................61.VARCHAR2(size):.............................................................................................................62.CHAR(size)..........................................................................................................................63.LONG........................................................................................................................................74.CLOB........................................................................................................................................75.NUMBER(p,s)...................................................................................................................76.DATE.........................................................................................................................................87.TIMESTAMP( factional_seconds_precision ).....................................................................8第二节 NULL.......................................................................................................................................8第三节 伪列.......................................................................................................................................111.CURRVAL 和 NEXTVAL........................................................................................................112.LEVEL.......................................................................................................................................