数据库简单语句 数据库语句总结

数据库基本语句？

select,update,delete,insert into ,drop create是基本语句，select 查询是基本的语句，做任何动作前要先查询；update更新数据，delete删除数数据；insert into插入数据；drop 删除对象；create 建立对象。

数据库简单语句 数据库语句总结

数据库简单语句 数据库语句总结

数据库简单语句 数据库语句总结

一个非常简单的数据库查询语句

给你伪代码吧，如下：

[外层循环开始] （如果你的程序需要插入很多，可以做个外层的循环）

rs.open "select from [表] where [要插入数据的条件]",connection..... （请遵循recordset 对象打开记录集的语法结构）

if rs.count=0 then （记录集对象如果数量是0，说明没有找到相同的）

for i=1 to 30

con.execute "插入语句" （循环插入30次）

next i

else

不满足条件时尽兴的作

end if

[外层循环结束]

数据库中常用的sql语句有哪些

select

into

from语句

要求目标表table_4不存在，因为在插入时会自动创建表table_4，并将table_3中指定字段数据到table_4中。

可以考虑使用如下语句:

insert

into

dbo.table_4

(sname,

semail)

(select

sname,

semail

from

table_3);

数据库得一些常用语句及其使用方法?

数据的作(增删改查)x0dx0a1.插入数据：x0dx0a（1）单行INSERT语句x0dx0aINSERT INTO [表名] (字段1,字段2) VALUES (100,'51WINDOWS.NET')x0dx0a（2）多行INSERT语句x0dx0aINSERT INTO [表名] (字段1,字段2) SELECT (字段1,字段2) FROM [表名2] WHERE [条件]x0dx0a2.删除数据：x0dx0aDELETE FROM [表名] WHERE [字段名]>100x0dx0a更新数据：x0dx0aUPDATE [表名] SET [字段1] = 200,[字段2] = '51WINDOWS.NET' WHERE [字段三] = x0dx0a'HAIWA

3.查询数据：x0dx0aselect (字段1,字段2) from [表名] where [条件] order by [字段] desc;x0dx0a4.删除表：x0dx0aDrop table [表名]x0dx0a5.新增字段：x0dx0aALTER TABLE [表名] ADD [字段名] NVARCHAR (50) NULLx0dx0a6.删除字段：x0dx0aALTER TABLE [表名] DROP COLUMN [字段名]x0dx0a7.修改字段：x0dx0aALTER TABLE [表名] ALTER COLUMN [字段名] NVARCHAR (50) NULL

数据库常用sql语句有哪些

数据库常用sql语句有哪些

SQL语句有哪些？SQL语句无论是种类还是数量都是繁多的，很多语句也是经常要用到的，下文我为大家分享的就是SQL的常用语句，仅供参考！

50个常用的sql语句

Student(S#,Sname,Sage,S) 学生表

Course(C#,Cname,T#) 课程表

SC(S#,C#,score) 成绩表

Teacher(T#,Tname) 教师表

问题：

1、查询“001”课程比“002”课程成绩高的所有学生的学号；

select a.S# from (select s#,score from SC where C#='001') a,(select s#,score

from SC where C#='002') b

where a.score>b.score and a.s#=b.s#;

2、查询平均成绩大于60分的同学的学号和平均成绩；

select S#,g(score)

from sc

group by S# hing g(score) >60;

3、查询所有同学的学号、姓名、选课数、总成绩；

select Student.S#,Student.Sname,count(SC.C#),sum(score)

from Student left Outer join SC on Student.S#=SC.S#

group by Student.S#,Sname

4、查询姓“李”的老师的个数；

select count(distinct(Tname))

from Teacher

where Tname like '李%';

5、查询没学过“叶平”老师课的同学的学号、姓名；

select Student.S#,Student.Sname

from Student

where S# not in (select distinct( SC.S#) from SC,Course,Teacher where SC.C#=Course.C# and Teacher.T#=Course.T# and Teacher.Tname='叶平');

6、查询学过“001”并且也学过编号“002”课程的同学的学号、姓名；

select Student.S#,Student.Sname from Student,SC where Student.S#=SC.S# and SC.C#='001'and exists( Select from SC as SC_2 where SC_2.S#=SC.S# and SC_2.C#='002');

7、查询学过“叶平”老师所教的所有课的同学的学号、姓名；

select S#,Sname

from Student

where S# in (select S# from SC ,Course ,Teacher where SC.C#=Course.C# and Teacher.T#=Course.T# and Teacher.Tname='叶平' group by S# hing count(SC.C#)=(select count(C#) from Course,Teacher where Teacher.T#=Course.T# and Tname='叶平'));

8、查询课程编号“002”的成绩比课程编号“001”课程低的所有同学的学号、姓名；

Select S#,Sname from (select Student.S#,Student.Sname,score ,(select score from SC SC_2 where SC_2.S#=Student.S# and SC_2.C#='002') score2

from Student,SC where Student.S#=SC.S# and C#='001') S_2 where score2

9、查询所有课程成绩小于60分的同学的学号、姓名；

select S#,Sname

from Student

where S# not in (select Student.S# from Student,SC where S.S#=SC.S# and score>60);

10、查询没有学全所有课的同学的学号、姓名；

select Student.S#,Student.Sname

from Student,SC

where Student.S#=SC.S# group by Student.S#,Student.Sname hing count(C#) <(select count(C#) from Course);

11、查询至少有一门课与学号为“1001”的同学所学相同的同学的学号和姓名；

select S#,Sname from Student,SC where Student.S#=SC.S# and C# in select C# from SC where S#='1001';

12、查询至少学过学号为“001”同学所有一门课的其他同学学号和姓名；

select distinct SC.S#,Sname

from Student,SC

where Student.S#=SC.S# and C# in (select C# from SC where S#='001');

13、把“SC”表中“叶平”老师教的课的成绩都更改为此课程的平均成绩；

update SC set score=(select g(SC_2.score)

from SC SC_2

where SC_2.C#=SC.C# ) from Course,Teacher where Course.C#=SC.C# and Course.T#=Teacher.T# and Teacher.Tname='叶平');

14、查询和“1002”号的同学学习的课程完全相同的其他同学学号和姓名；

select S# from SC where C# in (select C# from SC where S#='1002')

group by S# hing count()=(select count() from SC where S#='1002');

15、删除学习“叶平”老师课的SC表记录；

Delect SC

from course ,Teacher

where Course.C#=SC.C# and Course.T#= Teacher.T# and Tname='叶平';

16、向SC表中插入一些记录，这些记录要求符合以下条件：没有上过编号“003”课程的同学学号、2、

号课的平均成绩；

Insert SC select S#,'002',(Select g(score)

from SC where C#='002') from Student where S# not in (Select S# from SC where C#='002');

17、按平均成绩从高到低显示所有学生的“数据库”、“企业管理”、“英语”三门的课程成绩，按如下形式显示： 学生ID,,数据库,企业管理,英语,有效课程数,有效平均分

SELECT S# as 学生ID

,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='004') AS 数据库

,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='001') AS 企业管理

,(SELECT score FROM SC WHERE SC.S#=t.S# AND C#='006') AS 英语

,COUNT() AS 有效课程数, AVG(t.score) AS 平均成绩

FROM SC AS t

GROUP BY S#

ORDER BY g(t.score)

18、查询各科成绩和的分：以如下形式显示：课程ID，分，分

SELECT L.C# As 课程ID,L.score AS 分,R.score AS 分

FROM SC L ,SC AS R

WHERE L.C# = R.C# and

L.score = (SELECT MAX(IL.score)

FROM SC AS IL,Student AS IM

WHERE L.C# = IL.C# and IM.S#=IL.S#

GROUP BY IL.C#)

AND

R.Score = (SELECT MIN(IR.score)

FROM SC AS IR

WHERE R.C# = IR.C#

GROUP BY IR.C#

);

19、按各科平均成绩从低到高和及格率的百分数从高到低顺序

SELECT t.C# AS 课程号,max(course.Cname)AS 课程名,isnull(AVG(score),0) AS 平均成绩

,100 SUM(CASE WHEN isnull(score,0)>=60 THEN 1 ELSE 0 END)/COUNT() AS 及格百分数

FROM SC T,Course

where t.C#=course.C#

GROUP BY t.C#

ORDER BY 100 SUM(CASE WHEN isnull(score,0)>=60 THEN 1 ELSE 0 END)/COUNT() DESC

20、查询如下课程平均成绩和及格率的百分数(用"1行"显示): 企业管理（001），（002），OO&UML （003），数据库（004）

SELECT SUM(CASE WHEN C# ='001' THEN score ELSE 0 END)/SUM(CASE C# WHEN '001' THEN 1 ELSE 0 END) AS 企业管理平均分

,100 SUM(CASE WHEN C# = '001' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN C# = '001' THEN 1 ELSE 0 END) AS 企业管理及格百分数

,SUM(CASE WHEN C# = '002' THEN score ELSE 0 END)/SUM(CASE C# WHEN '002' THEN 1 ELSE 0 END) AS 平均分

,100 SUM(CASE WHEN C# = '002' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN C# = '002' THEN 1 ELSE 0 END) AS 及格百分数

,SUM(CASE WHEN C# = '003' THEN score ELSE 0 END)/SUM(CASE C# WHEN '003' THEN 1 ELSE 0 END) AS UML平均分

,100 SUM(CASE WHEN C# = '003' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN C# = '003' THEN 1 ELSE 0 END) AS UML及格百分数

,SUM(CASE WHEN C# = '004' THEN score ELSE 0 END)/SUM(CASE C# WHEN '004' THEN 1 ELSE 0 END) AS 数据库平均分

,100 SUM(CASE WHEN C# = '004' AND score >= 60 THEN 1 ELSE 0 END)/SUM(CASE WHEN C# = '004' THEN 1 ELSE 0 END) AS 数据库及格百分数

FROM SC

21、查询不同老师所教不同课程平均分从高到低显示

SELECT max(Z.T#) AS 教师ID,MAX(Z.Tname) AS 教师姓名,C.C# AS 课程ID,MAX(C.Cname) AS 课程名称,AVG(Score) AS 平均成绩

FROM SC AS T,Course AS C ,Teacher AS Z

where T.C#=C.C# and C.T#=Z.T#

GROUP BY C.C#

ORDER BY AVG(Score) DESC

22、查询如下课程成绩第 3 名到第 6 名的学生成绩单：企业管理（001），（002），UML （003），数据库（004）

[学生ID],[学生姓名],企业管理,,UML,数据库,平均成绩

SELECT DISTINCT top 3

SC.S# As 学生学号,

Student.Sname AS 学生姓名 ,

T1.score AS 企业管理,

T2.score AS ,

T3.score AS UML,

T4.score AS 数据库,

ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0) as 总分

FROM Student,SC LEFT JOIN SC AS T1

ON SC.S# = T1.S# AND T1.C# = '001'

LEFT JOIN SC AS T2

ON SC.S# = T2.S# AND T2.C# = '002'

LEFT JOIN SC AS T3

ON SC.S# = T3.S# AND T3.C# = '003'

LEFT JOIN SC AS T4

ON SC.S# = T4.S# AND T4.C# = '004'

WHERE student.S#=SC.S# and

ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0)

NOT IN

(SELECT

DISTINCT

TOP 15 WITH TIES

ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0)

FROM sc

LEFT JOIN sc AS T1

ON sc.S# = T1.S# AND T1.C# = 'k1'

LEFT JOIN sc AS T2

ON sc.S# = T2.S# AND T2.C# = 'k2'

LEFT JOIN sc AS T3

ON sc.S# = T3.S# AND T3.C# = 'k3'

LEFT JOIN sc AS T4

ON sc.S# = T4.S# AND T4.C# = 'k4'

ORDER BY ISNULL(T1.score,0) + ISNULL(T2.score,0) + ISNULL(T3.score,0) + ISNULL(T4.score,0) DESC);

23、统计列印各科成绩,各分数段人数:课程ID,课程名称,[100-85],[85-70],[70-60],[ <60]

SELECT SC.C# as 课程ID, Cname as 课程名称

,SUM(CASE WHEN score BETWEEN 85 AND 100 THEN 1 ELSE 0 END) AS [100 - 85]

,SUM(CASE WHEN score BETWEEN 70 AND 85 THEN 1 ELSE 0 END) AS [85 - 70]

,SUM(CASE WHEN score BETWEEN 60 AND 70 THEN 1 ELSE 0 END) AS [70 - 60]

,SUM(CASE WHEN score < 60 THEN 1 ELSE 0 END) AS [60 -]

FROM SC,Course

where SC.C#=Course.C#

GROUP BY SC.C#,Cname;

24、查询学生平均成绩及其名次

SELECT 1+(SELECT COUNT( distinct 平均成绩)

FROM (SELECT S#,AVG(score) AS 平均成绩

FROM SC

GROUP BY S#

) AS T1

WHERE 平均成绩 > T2.平均成绩) as 名次,

S# as 学生学号,平均成绩

FROM (SELECT S#,AVG(score) 平均成绩

FROM SC

GROUP BY S#

) AS T2

ORDER BY 平均成绩 desc;

25、查询各科成绩前三名的记录:(不考虑成绩并列情况)

SELECT t1.S# as 学生ID,t1.C# as 课程ID,Score as 分数

FROM SC t1

WHERE score IN (SELECT TOP 3 score

FROM SC

WHERE t1.C#= C#

ORDER BY score DESC

)ORDER BY t1.C#;

26、查询每门课程被选修的学生数

select c#,count(S#) from sc group by C#;

27、查询出只选修了一门课程的全部学生的学号和姓名

select SC.S#,Student.Sname,count(C#) AS 选课数

from SC ,Student

where SC.S#=Student.S# group by SC.S# ,Student.Sname hing count(C#)=1;

28、查询男生、女生人数

Select count(S) as 男生人数 from Student group by S hing S='男';

Select count(S) as 女生人数 from Student group by S hing S='女'；

29、查询姓“张”的.学生名单

SELECT Sname FROM Student WHERE Sname like '张%';

30、查询同名同性学生名单，并统计同名人数

select Sname,count() from Student group by Sname hing count()>1;;

31、1981年出生的学生名单(注：Student表中Sage列的类型是datetime)

select Sname, CONVERT(char (11),DATEPART(year,Sage)) as age

from student

where CONVERT(char(11),DATEPART(year,Sage))='1981';

32、查询每门课程的平均成绩，结果按平均成绩升序排列，平均成绩相同时，按课程号降序排列

Select C#,Avg(score) from SC group by C# order by Avg(score),C# DESC ;

33、查询平均成绩大于85的所有学生的学号、姓名和平均成绩

select Sname,SC.S# ,g(score)

from Student,SC

where Student.S#=SC.S# group by SC.S#,Sname hing g(score)>85;

34、查询课程名称为“数据库”，且分数低于60的学生姓名和分数

Select Sname,isnull(score,0)

from Student,SC,Course

where SC.S#=Student.S# and SC.C#=Course.C# and Course.Cname='数据库'and score <60;

35、查询所有学生的选课情况；

SELECT SC.S#,SC.C#,Sname,Cname

FROM SC,Student,Course

where SC.S#=Student.S# and SC.C#=Course.C# ;

36、查询任何一门课程成绩在70分以上的姓名、课程名称和分数；

SELECT distinct student.S#,student.Sname,SC.C#,SC.score

FROM student,Sc

WHERE SC.score>=70 AND SC.S#=student.S#;

37、查询不及格的课程，并按课程号从大到小排列

select c# from sc where scor e <60 order by C# ;

38、查询课程编号为003且课程成绩在80分以上的学生的学号和姓名；

select SC.S#,Student.Sname from SC,Student where SC.S#=Student.S# and Score>80 and C#='003';

39、求选了课程的学生人数

select count() from sc;

40、查询选修“叶平”老师所授课程的学生中，成绩的学生姓名及其成绩

select Student.Sname,score

from Student,SC,Course C,Teacher

where Student.S#=SC.S# and SC.C#=C.C# and C.T#=Teacher.T# and Teacher.Tname='叶平' and SC.score=(select max(score)from SC where C#=C.C# );

41、查询各个课程及相应的选修人数

select count() from sc group by C#;

42、查询不同课程成绩相同的学生的学号、课程号、学生成绩

select distinct A.S#,B.score from SC A ,SC B where A.Score=B.Score and A.C# <>B.C# ;

43、查询每门功成绩的前两名

SELECT t1.S# as 学生ID,t1.C# as 课程ID,Score as 分数

FROM SC t1

WHERE score IN (SELECT TOP 2 score

FROM SC

WHERE t1.C#= C#

ORDER BY score DESC

)ORDER BY t1.C#;

44、统计每门课程的学生选修人数（超过10人的课程才统计）。要求输出课程号和选修人数，查询结果按人数降序排列，查询结果按人数降序排列，若人数相同，按课程号升序排列

select C# as 课程号,count() as 人数

from sc

group by C#

order by count() desc,c#

45、检索至少选修两门课程的学生学号

select S#

from sc

group by s#

hing count() > = 2

46、查询全部学生都选修的课程的课程号和课程名

select C#,Cname

from Course

where C# in (select c# from sc group by c#)

47、查询没学过“叶平”老师讲授的任一门课程的学生姓名

select Sname from Student where S# not in (select S# from Course,Teacher,SC where Course.T#=Teacher.T# and SC.C#=course.C# and Tname='叶平');

48、查询两门以上不及格课程的同学的学号及其平均成绩

select S#,g(isnull(score,0)) from SC where S# in (select S# from SC where score <60 group by S# hing count()>2)group by S#;

49、检索“004”课程分数小于60，按分数降序排列的同学学号

select S# from SC where C#='004'and score <60 order by score desc;

50、删除“002”同学的“001”课程的成绩

delete from Sc where S#='001'and C#='001'; ;

数据库增删改查基本语句

1、“INSERT INTO”语句，用于向表格中增加新的行。

2、“DELETE”语句，用于删除表中的行。

3、“Update”语句，用于修改表中的数据。

4、“SELECT”语句，用于从表中选取数据。

sql语言特点：

SQL可以完成数据库生命周期中的全部活动，包括定义关系模式、录入数据、建立数据库、查询、更新、维护、数据库重构、数据库安全性控制等一系列作，这就为数据库应用系统开发提供了良好的环境，在数据库投入运行后，还可根据需要随时逐步修改模式，且不影响数据库的运行，从而使系统具有良好的可扩充性。