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So my parents do Nor my parents do Nor do my parents So do my parents
So my parents do Nor my parents do Nor do my parents So do my parents
The parents as well as their child Not the parents but their child Neither the child nor his parents Both the parents and their child
do your parents come does your parents come have your parents our parents come
Ⅰ和Ⅱ Ⅰ和Ⅲ Ⅱ和Ⅲ Ⅰ、Ⅱ和Ⅲ 第(39)至(41)题,基于“学生—选课-课程”数据库中如下三个关系: S(S#,SNAME,SEX,AG,SC(S#,C#,GRAD ,C(C#,CNAME,TEACHE
So my parents do Nor my parents do Nor do my parents So do my parents
The parents as well as their child Not the parents but their child Neither the child nor his parents Both the parents and their child
The parents as well as their child Not the parents but their child Neither the child nor his parents Both the parents and their child
John as well as his parents John’s parents as well as John John and his parents John’s parents and John
So my parents do Nor my parents do Nor do my parents So do my parents
(S#,C#) (S#,GRADE) (C#,GRADE) GRADE
parent’s parents’ parents parents’s
向关系SC插入元组时,S#和C#都不能是空值(NUL 可以任意删除关系SC中的元组 向任何一个关系插入元组时,必须保证关系主码值的唯一性 可以任意删除关系C中的元组
parent parents parents' parents's
care the parents the parents do care the parents care do the parents care
只有S,SC 只有SC,C 只有S,C S,SC,C
it;whom himself;who this;whom that;who
their parents; they aren't their parents; aren't his parents; they are their parents; their aren't