2022年6月7日
Lecture 05 Intro to SQL (Continued)
摘要： Null Values： It is possible for tuples to have a null value, denoted by null, for some of their attributes. null signifies an unknown value or that a 阅读全文
posted @ 2022-06-07 22:06 M1stF0rest 阅读(87) 评论(0) 推荐(0)