⑴ sql语句查询查看90分以上学生的成绩.课程名称.学生姓名怎么写
select 成绩,课程名称,姓名 from 成绩,学生基本信息,课程名称 where学生基本信息.学号=成绩.学号 and 成绩.课程编号=课程名称.课程编号 and 成绩>90
⑵ 如何用sql语句查出学生表成绩小于60为不及格60-80为良好80-90为优秀
select name，case when 成绩<60 then 不及格 when 成绩>=60 and 成绩<80 then 良好 when 成绩>=0 and 成绩<90 then 优秀 end as 成绩情况 ，from 表名。
注意，在输入sql语句的时候，要在英文环境下输入。否则可能会出现代码不识别。
⑶ SQL SEVER中的兼容级别具体是干什么用的
SQL sever中的兼容级别指的是：将某些数据库行为设置为与指定的 SQL Server 版本兼容。
适用范围：SQL Server（SQL Server 2008 到当前版本）；
参数：
database_name
要修改的数据库的名称。
COMPATIBILITY_LEVEL {80 | 90 | 100 | 110 | 120 }
要使数据库与之兼容的 SQL Server 版本。该值必须为下列值之一：
⑷ 什么是sql
SQL是一种结构化查询语言即Structure Query Language
一般格式：
SELECT[DISTINCT]<目标列表达式>…
FROM<表名>，<查询名>……
[WHERE <条件表达式>]
[GROUP BY<列名1>[HAVING<条件表达式>]
[ORDER BY<列名2>[ASC│DESC];
SELECT SNAME,SDEPT FROM STUDENT
SELECT SNO,CNO FROM 查询1
SELECT * FROM STUDENT
SELECT DISTINCT SNO FROM SC
SELECT SNAME,SAGE FROM STUDENT WHERE SDEPT='CS'
WHERE SAGE NOT BETWEEN 10 AND 18
'',"";
BETWEEN #1978-01-01# AND #1980-12-31#
*,?,#
'' ""
IN NOT IN
WHERE SDEPT IN('CS','IS'); SDEPT='CS' OR SEPT='IS'
LIKE *,?,#
SELECT * FROM STUDENT WHERE SNAME LIKE '刘?'
SAGE LIKE '1#'
1按学生成绩降序排序，成绩相同按课程号排序
select * from sc order by grade desc,cno
2安课程号排序，课程号相同按成绩将需排列
IS NULL,IS NOT NULL
SELECT SNO,CNO FROM SC WHERE GRADE IS NULL
count(*),count(CNO),sum(),avg(),min(),max()
select count(*) from sc
select cno,count(*) from sc group by cno
and or not
select sname ,2003-sage as 出生年份 from student
SELECT SC.SNO,SNAME,CNO FROM STUDENT,SC WHERE STUDENT.SNO=SC.SNO
SELECT C1.CNO,C2.CPNO FROM COURSE C1,COURSE C2 WHERE C1.CPNO=C2.CNO
LEFT JOIN RIGHT JOIN
SELECT course.*, sc.*
FROM course LEFT JOIN sc ON course.cno = sc.cno;
SELECT SNAME+SDEPT AS SNSD FROM STUDENT
1查询信息系年龄在18到20之间的学生信息
SELECT *
FROM STUDENT
WHERE SDEPT='IS'AND SAGE BETWEEN 18 AND 20;
2查询每门课程相应的选课人数
SELECT CNO,COUNT(SNO)
FROM SC
GROUP BY CNO;
SELECT COUNT(*) FROM SC
3查询每个学生不及格课程门数
SELECT CNO,COUNT(CNO)
FROM SC
WHERE GRADE<60
GROUP BY SNO
4查询成绩在90到100份之间的每门课程的选修人数
SELECT CNO, COUNT( SNO)
FROM SC
WHERE GRADE BETWEEN 90 AND 100
GROUP BY CNO ;
5查询姓名第二个字是“力”的学生姓名和所在系
SELECT SNAME,SDEPT
FROM STUDENT
WHERE SNAME LIKE "?力*";
6查询没有成绩的学生学号和对应的课程号
SELECT SNO,CNO
FROM SC
WHERE GRADE IS NULL;
7查询数学系和信息系所有男学生的情况
SELECT *
FROM STUDENT
WHERE SDEPT ="IS" OR SDEPT= "MA" AND SSEX="男";
8查询总成绩大于200分的学生学号
SELECT SNO
FROM SC
GROUP BY SNO HAVING SUM(GRADE)>200;
SELECT * FROM SC ORDER BY SNO ,GRADE DESC
1.SELECT ENO,ENAME FROM EMP,WORKS WHERE
CMP.ENO=WORKS.ENO,SEX='男',AGE>50
2.SELECT ENO,ENAME FROM EMP ,WORKS WHERE SALARY>1000 AND EMP.ENO=WORKS.ENO
3.SELECT ENO,ENAME FROM EMP,COMP,WORKS WHERE CNAME="LHGS" AND WORKS.CNO=COMP.CNO AND EMP.ENO=WORKS.ENO
4.SELECT ENO,ENAME FROM EMP,COMP,WORKS WHERE WORKS.CNO=COMP.CNO AND EMP.ENO=WORKS.ENO AND SEX='M'AND CNAME='LHGS' AND SALARY>1000
left join right jion
select * from student left join sc on studnt.sno=sc.sno
#1987-10-01#
1、select distinct sno from sc where grade<60
2 select * from student where sdept in('cs','is')
select * from student where sdept='cs' or sdept='is'
3 select sno,sname,sage from student where sage between 10 and 19
>=10 and <=19
like '1#'
4 select sname ,sdept from student where sname like '?力*'
5 select sno from sc where grade is not null
子查询
概念：
分类：
引导谓词：select from where sage>(select sage from student where sdept='cs')
>，=，<
查询和刘晨同在一个系学习的学生
SELECT S1.* FROM STUDENT S1,STUDENT S2 WHERE S2.SNAME='刘晨' AND S1.SDEPT=S2.SDEPT
SELECT *
FROM STUDENT
WHERE SDEPT=
(SELECT SDEPT
FROM STUDENT
WHERE SNAME='刘晨')
select sname from student where sdept=(select sdept from student where sname='刘晨')
in
查询选修了数据库课程的学生的姓名和所在系
SELECT SNAME,SDEPT
FROM STUDENT
WHERE SNO IN
( SELECT SNO
FROM SC
WHERE CNO IN
(SELECT CNO
FROM COURSE
WHERE CNAME='数据库'))
select sname ,sdept
from student
where sno in
(select sno
from sc
where cno=
(select cno
from course
where cname='数据库'))
select sname ,sdept
from student,sc,course
where student.sno=sc.sno and sc.cno=course.cno and cname='数据库'
查询其他系比信息系任一学生年龄小的学生情况
any,all
>any大于子查询结果中的某个值(>min()大于最小值）
>all大于子查询结果中的所有值(>max()大于最大值）
<any小于子查询结果中的某个值(<max()小于最大值）
<all小于子查询结果中的所有值(<min()小于最小值）
SELECT *
FROM STUDENT
WHERE SAGE<(SELECT max(SAGE)
FROM STUDENT WHERE SDEPT='IS')
AND SDEPT<>'IS'
select sname
from student
where sage <any(select sage from student where sdept='is') and sdept <>'is'
集合查询
并（UNION）、交、差
查询既选修了1号课程又选修了2号课程的学生学号。
SELECT SNO FROM SC WHERE CNO=1 AND SNO IN(SELECT SNO FROM SC WHERE CNO=2)
exists
网络班
查询选修了全部课程的学生姓名
select sname
from student
where sno in
(select sno
from sc
group by sno having count(*)=
(select count(*)
from course) )
使用EXISTS
SELECT SNAME
FROM STUDENT
WHERE NOT EXISTS
(SELECT *
FROM COURSE
WHERE NOT EXISTS
(SELECT *
FROM SC
WHERE SNO=STUDENT.SNO
AND CNO=COURSE.CNO))
查询至少选修了01001选修的全部课程的学生号码
select sno from sc where cno in(select cno from sc where sno=01001) group by sno having count(*)=(select count(*) from sc where sno=01001)
SELECT SNAME FROM STUDENT
WHERE SNO IN(SELECT SNO FROM SC WHERE CNO IN(SELECT CNO FROM COURSE WHERE CNAME='数据库'))
更新查询
插入（INSERT INTO）
INSERT INTO STUDENT VALUES(95033,'','IS','男',19)
INSERT INTO C1(CPNO,CNAME)
SELECT CPNO,CNAME FROM COURSE WHERE CNO IN(1,2)
INSERT INTO SC1(SNO,CNO)
SELECT SNO,CNO FROM STUDENT,COURSE
修改(UPDATE)
UPDATE SC SET GRADE=0 WHERE 'IS'=(SELECT SDEPT FROM STUDENT WHERE SNO=SC.SNO )
删除(DELETE)
DELETE FROM C1
DELETE FROM SC WHERE 'IS' =(SELECT SDEPT FROM STUDENT WHERE SNO=SC.SNO)
UPDATE STUDENT SET SNO=95030 WHERE SNO=95004
⑸ 心理测试sql-90到底是什么
《症状自评量表SCL90》是世界上最着名的心理健康测试量表之一，是当前使用最为广泛的精神障碍和心理疾病门诊检查量表，将协助您从十个方面来了解自己的心理健康程度。 本测验适用对象为16岁以上的用户。
⑹ sql查询语句的问题，“列出成绩大于90的所有学生的姓名、专业、课程名称、成绩”这条语句怎么写
可以参考下面的代码：
select s.姓名, s.专业, sc.成绩, c.课程名称
from 学生基本情况表 s, 成绩表 sc, 课程表 c
where s.学号 = sc.学号 and c.课程编号 = sc.课程编号
and sc.成绩 > 90
(6)sql到90是什么意思扩展阅读：
sql语句
删除列：
Alter table table_name drop column column_name--从表中删除一列
添加主键：
Alter table tabname add primary key(col)
平均：
select avg(field1) as avgvalue from table1
最大：
select max(field1) as maxvalue from table1
⑺ sql语句查询分数大于90和分数不为零的语句
select * from table_name
where 分数>90
--满足大于90就不为零了
⑻ SQL中根据学生成绩然后在查找结果中输出评价，如大于90分在查找结果后显示‘优’，89~90显示‘良’
对于SQL SERVER数据库，可以用以下的方式查询，当然你的字段名需要自己修改。
select 学生姓名,学生成绩,case when 学生成绩>90 then '优' when 学生成绩>89 then '良' end as 评价 from 学生成绩表
⑼ 用SQL查询平均成绩高于90分的同学的学号、姓名及其平均成绩,并按成绩由高到低排序
应该不只一张表 学生信息表info_student 成绩表 info_score
select *, avgs from info_student s inner join
(select uid,avg(score) avgs from info_score group by uid having avg(score)>90) a
on s.uid = a.uid