成绩表(CJB)结构列名                          可空值否   类型               备注
------------------------------- -------- ----
KCH                             NOT NULL VARCHAR2(10)       课程号
KCM                                      VARCHAR2(50)       课程名
KXH                                      NUMBER(4)          课序号
XH                              NOT NULL VARCHAR2(12)       学号
XNXQ                                     VARCHAR2(11)       学年学期
XF                                       NUMBER(5,1)        学分
XS                                       NUMBER(4,1)        学时数
KCSX                                     VARCHAR2(4)        课程属性(必修,限选,任选)
KSCJ                                     NUMBER(5,1)        考试成绩
...学籍表(XJB)结构:列名                          可空值否   类型            备注
------------------------------- -------- ----
XH                              NOT NULL VARCHAR2(12)    学号
XM                              NOT NULL VARCHAR2(40)    姓名
XB                                       VARCHAR2(2)     性别
XSH                                      VARCHAR2(5)     系所号
ZYH                                      VARCHAR2(8)     专业号
ZYFX                                     VARCHAR2(30)    专业方向(专业名)
BM                                       VARCHAR2(10)    班级名称
RXNJ                                     VARCHAR2(4)     入学年级
SSNJ                                     VARCHAR2(4)     所属年级
PYFS                                     VARCHAR2(20)    培养方式(层次)
CXBKBZ                                   VARCHAR2(4)     成绩补考备注(补考,重修,辅修)
...系所表(XSB)结构:列名                          可空值否   类型             备注
------------------------------- -------- ----
XSH                             NOT NULL VARCHAR2(5)      系所号
XSM                                      VARCHAR2(30)     系所名称学分绩点转化表(XFJ)结构: 列名                          可空值否   类型
 ------------------------------- -------- ----
 JDH                             NOT NULL NUMBER(2)
 JDS                                      NUMBER(2,1)
 XXF                                      NUMBER(5,1)
 SXF                                      NUMBER(5,1)
 BZ                                       VARCHAR2(20)   
以下是XFJ内的数据(各课程成绩通过这张表转换):JDH       JDS       XXF       SXF BZ 
--- --------- --------- --------- -------------- 
  1         4        90       100 A(优) 
  2       3.7        87      89.9 A- 
  3       3.3        84      86.9 B+ 
  4         3        81      83.9 B(良) 
  5       2.7        78      80.9 B- 
  6       2.3        75      77.9 C+ 
  7         2        72      74.9 C(中) 
  8       1.7        69      71.9 C- 
  9       1.3        66      68.9 D+ 
 10         1        60      65.9 D 
 12         0         0      59.9 F(不及格)     如何用sql语句生成如下的形式呢?  
系别  学号  性别 专业  培养层次  必修课总学分  限选课总学分  任选课总学分(通识、复合) 任选课总学分(教育类) 重修课程门次 重修课程总学分  平均学分绩点  注:任选课(通识、复合)课程名里都有“复合”二字  ,任选课(教育类)课程号前面是"JY"  
   平均绩点计算方式为:每门课程绩点*学分/总学分  任选,限选,必修是在课程属性字段里