MiniDatabase
1Ϸж
ݿ03ĸѡ
ַַ򳬹ͷΧ磺aʾ벻Ҫַ
03δͷΧ磺4ʾûиѡ

˵ѡһ

2ݿ
ݿڣtestʾtestݿѴڣ
test1MiniDatabaseļ´test1ļСʾtest1ݿⴴɹ
ݿв

3
ʾһű

student
sno
1
11
1
1
name
0
8
0
0
ɹʾϢMiniDatabaseݿļtest1´ñstudentıļ

4׷Data
astudentaڡʾñڣһ
ʾݡ

һ㱨ʾ
Ըԣ20071610101/bao/1/ʾԸһ£
ͻ򳤶Ȳԣ20071610101a/1.0/ʾ1Ͳ1Ȳ2Ͳ

ʾ
Ϊգ/bao/NULL/bao/ʾΪգ
20071610101/bao/ȷ
ظ20071610101/cai/ʾظ

׷
20071610102/cai/
20071610103/ding/
20071610124/zeng/
20071610127/zhu/
20071610128/li/

ʾ
courseʾ

5Column
ʾColumn

class
1
1
0
ĬΪNULLݲNULL
λòڷΧڡʾcolumn4ʧܣ

a
1
1
9

6׷Column
ơλá

sex
0
6

7ɾColumn
ColumnڣaʾвڣColumnһ
ڣɾclass
courseʾ

8޸Column
޸ֶ͡ĬΪNULL

sname
0
name

9ɾData
ɾData
ColumnsnoʾݲƳ
ݲڡʾݲڣ
ȷɾ
sname
li
ΪNULL

ɾData
ҪƳ20071610102ݽƳ
ڡʾڣ
ݲڡʾݲڣ

courseʾ

10޸Data
罫ѧ20071610128Ϊ20071610102
sno
20071610128
20071610102
޸sex

sex
NULL
ݸ¼

11Χѯ
ݿtest studentв

12ɾݿ
test
MiniDadabaseļ£testļмļtestıļɾ

13Column
test1ݿ
course

course
sno
1
11
2
student
sno
1
cno
1
6
0
1
score
2
6
0
0
ڡʾñڣcolumnΪĬֵNULL
ColumnڡвڣcolumnΪĬֵNULL

14ɾ
ɾstudentʾñɾ

15ɾColumn
ɾstudent Column snoʾƳ
ɾstudent Column sexɹ

16޸ĹColumn

ID
1
sno
ʾ޸ģ

17׷Data
course׷Data
ݲڣ20071610128/01/80.0/ʾcolumnsnostudentsnoݣ20071610128ڣ
ȷ׷
20071610101/01/81.1/
20071610127/01/85.0/

18ɾData
ɾstudent 20071610101ʾݲƳ
ȷɾɾ޸ıcourse 20071610101ɾstudent 20071610101

19޸ĹData
޸ıstudent 20071610127ʾݲ޸ģ
ȷ޸ģɾ޸ıcourse 20071610127޸ıstudent 20071610127

20ȷɾColumn
ɾcoursesnocourseɾstudentsnostudent