有S,C,SC三个关系,用关系代数表示下列查询:有S,C,SC三个关系,student(sno,sname,ssex,sage,sdept)course(cno,cname,cpno,ccredit),SCG(sno,cno,grade),用关系代数表示下列查询:(1) 检索Li老师所授课程的课程号、
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/17 03:11:20
![有S,C,SC三个关系,用关系代数表示下列查询:有S,C,SC三个关系,student(sno,sname,ssex,sage,sdept)course(cno,cname,cpno,ccredit),SCG(sno,cno,grade),用关系代数表示下列查询:(1) 检索Li老师所授课程的课程号、](/uploads/image/z/8549450-26-0.jpg?t=%E6%9C%89S%2CC%2CSC%E4%B8%89%E4%B8%AA%E5%85%B3%E7%B3%BB%2C%E7%94%A8%E5%85%B3%E7%B3%BB%E4%BB%A3%E6%95%B0%E8%A1%A8%E7%A4%BA%E4%B8%8B%E5%88%97%E6%9F%A5%E8%AF%A2%EF%BC%9A%E6%9C%89S%2CC%2CSC%E4%B8%89%E4%B8%AA%E5%85%B3%E7%B3%BB%2Cstudent%EF%BC%88sno%2Csname%2Cssex%2Csage%2Csdept%EF%BC%89course%28cno%2Ccname%2Ccpno%2Cccredit%29%2CSCG%28sno%2Ccno%2Cgrade%29%2C%E7%94%A8%E5%85%B3%E7%B3%BB%E4%BB%A3%E6%95%B0%E8%A1%A8%E7%A4%BA%E4%B8%8B%E5%88%97%E6%9F%A5%E8%AF%A2%EF%BC%9A%281%29+%E6%A3%80%E7%B4%A2Li%E8%80%81%E5%B8%88%E6%89%80%E6%8E%88%E8%AF%BE%E7%A8%8B%E7%9A%84%E8%AF%BE%E7%A8%8B%E5%8F%B7%E3%80%81)
x[oEǿJ[ʖLtncFg G:w:7xHWKgқK)B3 l}u
@q*]:JN_{ӫEڕ [OBdm
s U*OJzf}>y~лƝQ<٭ht$m>m qW[f{2҂˛ӅխYc-!^2Md~`b2lΧ9wzsi免mp[R'kOw7/~5mO9/=)C:eP+3~pbdm?sKʼnuAb6Q6e.=Ͼ0xϮxڎ)jշH\-Ujx;:b+G_NW_ҷB{IA!˓STreP
|"D!B8oJ"2J:AHRD(P#VxEYReEICGɒv7IE*h"8Fc91ymqSI!,A\2L0i#6Dm[-9vFP+XQ
AߑozHDfj0b[1iqQ
ɃgJjҰߔHm[-Q`D9s[@J*lĆd&
}Gt4Y3¾)Wr[,[!iXDBq!Q 摧&HD,ڛA-0R#䡒`d"BQI D`EƠ(\`k0 R,W@QksQ\k.pD&0^