文件名称:三个关系表-b样条插值(b-spline interpolation)
文件大小:8.74MB
文件格式:PDF
更新时间:2024-06-30 14:47:14
数据库原理
图 3.3 三个关系表 答:(1)SELECT A#,ANAME FROM A WHERE WQTY<=100 OR CITY='长沙' (2)方法一: SELECT A.ANAME FROM A,B,AB WHERE A.A#=AB.A# AND B.B#=AB.B# AND B.BNAME='书包' 方法二: SELECT ANAME FROM A WHERE A# IN (SELECT A# FROM AB WHERE B# IN (SELECT B# FROM B WHERE BNAME='书包')) (3)SELECT A.ANAME,A.CITY FROM A,AB WHERE A.A#=AB.A# AND AB.B# IN (SELECT AB.B# FROM AB WHERE A#='256') 【例 3.37】设有图书登记表 TS,具有属性:BNO(图书编号),BC(图书类别), BNA(书名),AU(著者),PUB(出版社)。按下列要求用 SQL语句进行设计: