【正文】
20141126實(shí)驗(yàn)名稱數(shù)據(jù)查詢實(shí)驗(yàn)學(xué)時(shí)4準(zhǔn)備材料1. SQL Plus命令手冊(cè)2. Oracle數(shù)據(jù)字典擴(kuò)展實(shí)驗(yàn)1. 利用企業(yè)管理器的圖形界面構(gòu)造查詢語句,并察看查詢結(jié)果2. 利用企業(yè)管理器完成視圖、索引的創(chuàng)建與使用。3. 利用DBMS進(jìn)行對(duì)第三章習(xí)題所設(shè)計(jì)SQL語句的檢查 (此部分內(nèi)容不要求在實(shí)驗(yàn)室完成,不用寫入實(shí)驗(yàn)報(bào)告。Comp. Sci.39。t display the tot_creds value from the student table, you should use SQL aggregation on courses taken by the student. SELECT id,SUM(credits)FROM takes NATURAL JOIN student NATURAL JOIN courseWHERE id = 12345GROUP BY id。 don39。t bother about students who have not registered for any course, they can be omitted) SELECT id,SUM(credits)FROM takes NATURAL JOIN student NATURAL JOIN courseGROUP BY id(4) Find the names of all students who have taken any Comp. Sci. course ever (there should be no duplicate names) SELECT DISTINCT id,NAMEFROM takes NATURAL JOIN studentWHERE course_id IN (SELECT course_id FROM course