高中生如何提高学习效率
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函数怎么学最简单最学习方法
2021-10-01
如何报名自考
按照你提问的内容顺序回答你，以下内容希望对你有所帮助：1、怎样才能报名自考？自考有什么要求？初高中学历可以报读大专，大专学历可以直接报读本科，如果没有大专你还想报读本科也可以，那么需要专本套读，也就是你大专也要报，可以通过自考，成考，网教，国开等形式报读大专，同时报读自考本科；自考属于宽进严出，报考没什么要求；2、一般怎么学习，学习资料从哪获取？大部分报考自考的考生都会通过报读社会机构学习，有线上和线下两种形式，根据自己的时间选择不同形式学习，机构会提供全套教学内容，包括你提到的学习资料（视频、课件、讲义、题库、精讲、串讲、重点、难点、考点、疑点），当然需要培训费用，一般5000-10000不等，不同班型不同学习价格不同；个别人不通过机构自己学习，会自己买一套教材，上网零星的下载资料，不过这样自己没目标没方法的学习考试通过率极地，个人建议如果你想通过自考形势考取学历，一定要报读培训机构，考试是有方法的，你自己笨笨的学很难，毕竟不是考一科，要十几科，缺一不可；3、报考学校大部分你知道的大学都是主考院校，都招生自学考试学生，你在当地选择一个你认为较好的学校即可，这个不复杂，也不重要，因为大多数学校级别差不多，关键是专业，虽然你没问，我也提及下，专业选择影响你考试顺利与否，比如会计专业，不同主考院校考试科目就可能有所不同，有些涵盖了高级财务会计、线性代数、计算机应用等较难学科，增加了你考试通过难度性，有些院校会计专业就没考这些，所以选择专业很重要，不要固执的盯着你要的那个专业，记住考证是目的，专业和院校不是第一选择，顺利拿下才是王道；4、报考时间、注册事宜:每年1、4、10月考试，一年三次，关注当地自考办官网，一般提前一个多月进行网上报名，注册也是自考办官网注册，如果你报读了机构，这些事情机构会协助你处理，一点不复杂，就算你不报读机构自己在官网也能看懂报考流程，不过抢考场还是个技术活，一般一线城市的考场都比较难抢，这个要注意；以上简单的分享了一下你所关注的几个问题，其实还有很多细节，如果需要欢迎关注本人，我分享过很多关于自考方面的文章，也许对你有帮助。欢迎关注@老孙浅谈系列
如何学习SQL语言
掌握这50句常用SQL基本就差不多了。建议自己在数据库建立好以下几张表，然后自己对照这些例子逐个全部试一遍，并理解透彻。数据表准备Student(S#,Sname,Sage,Ssex) 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#,avg(score) from sc group by S# having avg(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#,Sname4、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# having 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 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 having 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 avg(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# having 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 avg(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 avg(t.score) 18、查询各科成绩最高和最低的分：以如下形式显示：课程ID，最高分，最低分 SELECT L.C# As 课程ID,L.score AS 最高分,R.score AS 最低分 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# );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) DESC22、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），马克思（002），UML （003），数据库（004） [学生ID],[学生姓名],企业管理,马克思,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 马克思, 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 ,Studentwhere SC.S#=Student.S# group by SC.S# ,Student.Sname having count(C#)=1;28、查询男生、女生人数 Select count(Ssex) as 男生人数 from Student group by Ssex having Ssex='男'; Select count(Ssex) as 女生人数 from Student group by Ssex having Ssex='女'；29、查询姓“张”的学生名单 SELECT Sname FROM Student WHERE Sname like '张%';30、查询同名学生名单，并统计同名人数select Sname,count(*) from Student group by Sname having 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# ,avg(score) from Student,SC where Student.S#=SC.S# group by SC.S#,Sname having avg(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，成绩最高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、查询每门功成绩最好的前两名 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# having count(*) > = 246、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#,avg(isnull(score,0)) from SC where S# in (select S# from SC where score <60 group by S# having 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';