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sql面試經典500題

發布時間: 2022-06-22 14:29:47

⑴ 經典的sql面試題目,百度有答案,誰有更簡潔的

select a.id,a.proid as pro1,b.proid as pro2 from (select * from tablename where proid =1) a,(select * from tablename where proid =2) b where a.id=b.id

⑵ SQL語句面試題

SELECT*,
(SELECTCOUNT(*)FROM(SELECTCOUNT(*),b.sidFROMscbLEFTJOINcoursecONb.Cid=c.CidGROUPBYb.sid,c.tid)owWHEREow.sid=a.sid)as'
選課數量',
(SELECTsum(Score)FROMScdWHEREa.sid=d.sid)as'總成績'
FROMstudenta
;

SELECTd.sid,d.snamefromteachera
LEFTJOINcoursebona.tid=b.tid
LEFTJOINscconc.cid=b.cid
leftJOINstudentdONd.sid=c.sid
WHEREa.tname='葉萍';

SELECTsid,sname
FROMstudent
WHEREsidin(selecta.sid
FROMscAleftjoinscbona.sid=b.sid
WHEREa.cid=1andb.cid=2anda.score>b.score)

SELECTsc.Sid,sum(CASEWHENc.Cname='
數學'thensc.Scoreelse0end)數學,SUM(casewhenc.Cname='物理
'THENsc.ScoreELSE0END)物理,AVG(sc.Score)平均分
FROMsc
INNERJOINCourseconsc.Cid=c.Cid
WHEREc.Cnamein('數學','物理')
GROUPBYsc.Sid
ORDERBYAVG(sc.Score)DESC

insertintoSc(Sid,Cid,Score)values(003,3,85);

insertintoSc(Sid,Cid,Score)values(003,3,30);

首先這個不知道是你i寫錯了還是怎麼一個人化學成績有2個所以我在這里按照你這個上做的查詢所以有一個人是選了單個課程

⑶ SQL面試題

select name
from
(
select name,sum(score) sc
from 表

group by name
) t1
where t1.sc>200
這樣?

⑷ sql面試題

1,答
select * into B庫.table_b from A庫.table_a

2,答
select * into A庫.new_table from A庫.table_a left outer join B庫.table_b on A庫.table_a.name=B庫.table_b.name and A庫.table_a.Text=B庫.table_b.text

delete from A庫.table_a left outer join A庫.new_table on A庫.table_a.name=A庫.new_table.name and A庫.table_a.Text=A庫.new_table.text
delete from B庫.table_b left outer join A庫.new_table on b庫.table_b.name=A庫.new_table.name and b庫.table_b.Text=A庫.new_table.text

3 答

select * from (select top 10 * from (select top 100 * from 表 )as a) as b

4 答
select * into 表c from 表A
union all
select * into 表c from 表B

試試如果不對請指正。

⑸ SQL資料庫面試題 急急急

a)select pname as '商品名',avg(qty) as 平均銷售量 from s,p,m where m.city='上海' and s.mno=m.mno and p.pno=s.pno,select p.Pno,p.pname,sum(s.qty)
from s left join p on s.pno=p.pno left join m on p.Mno=m.Mno
where m.city='上海市'
group by p.Pno,p.pname,p.city,p.color
b)、先刪除Sale表的外鍵PNO,再刪除gds表。

c)聯系:視圖(view)是在基本表之上建立的表,它的結構(即所定義的列)和內容(即所有數據行)都來自基本表,它依據基本表存在而存在。一個視圖可以對應一個基本表,也可以對應多個基本表。視圖是基本表的抽象和在邏輯意義上建立的新關系
區別:1、視圖是已經編譯好的sql語句。而表不是
2、視圖沒有實際的物理記錄。而表有。
3、表是內容,視圖是窗口
4、表只用物理空間而視圖不佔用物理空間,視圖只是邏輯概念的存在,表可以及時四對它進行修改,但視圖只能有創建的語句來修改
5、表是內模式,視圖是外模式
6、視圖是查看數據表的一種方法,可以查詢數據表中某些欄位構成的數據,只是一些SQL語句的集合。從安全的角度說,視圖可以不給用戶接觸數據表,從而不知道表結構。
7、表屬於全局模式中的表,是實表;視圖屬於局部模式的表,是虛表。
8、視圖的建立和刪除隻影響視圖本身,不影響對應的基本表。

⑹ 面試題目(sql)

1、忍不住想說一句,因為第一題中的欄位類型是
【日期型】,而各種資料庫操作日期型數據有不同的方法,沒有一種共通的方法,所以脫離了資料庫而言沒有一種共通的sql。
2、select
ID,NAME,ADDRESS,PHONE,LOGDATE
from
T
where
ID
in(
select
ID
from
T
group
by
NAME
having
count(*)>1)
order
by
NAME;
3、delete
from
T
where
ID
not
in
(select
min(id)
from
T
group
by
name);
4、update
T
set
T.ADDRESS=(select
E.ADDRESS
from
E
where
E.NAME=T.NAME),
T.PHONE=(select
E.PHONE
from
E
where
E.NAME=T.NAME);
5、這個不同的資料庫也有不同的處理方法,不能脫離資料庫談了。
如:SqlServer或者access可以使用
top
oracle可以使用
rownum

---
以上,希望對你有所幫助。

⑺ sql面試題,請大神解答,急!!!

第一題,最高的10-20。
1234select*from(selectcolD,colE,dense_rank()over(orderbycolGdesc)asrkfromtableb)whererkbetween10and20--當然面試的話這里可以註明dense_rank和rank區別等等。

第二題,2樓寫的就可以了

第三題,注意題目是人數之和
12345selectcount(*)ascntfromtableBwherecolAin(=傳入idconnectbypriorcolA=colB)

第四題
--測試數據
withtableAas(select1ascolA,0ascolB,'北京',0ascolB,'上海'fromal),tableBas(select1ascolD,'人員1'ascolE,1ascolA,2000ascolG,0ascolHfromalunionallselect2,'人員2',1,2000,0fromalunionallselect3,'人員3',1,2000,0fromalunionallselect4,'人員4',1,2000,0fromalunionallselect5,'人員5',1,2000,1fromalunionallselect6,'人員6',2,2000,1fromalunionallselect7,'人員7',1,2000,1fromal)--查詢sqlselectdecode(t.colH,0,'女','男')asgender,max(decode(t.colC,'北京',t.cnt,0))as北京,max(decode(t.colC,'上海',t.cnt,0))as上海from(selecta.colC,b.colH,count(*).colA=b.colAgroupbycolC,colH)tgroupbyt.colH
這里可以解釋下本sql的思路:--首先查出每個地區不同性別的人數,在行轉列(由於題目很明顯告訴你固定數據)

⑻ sql語句 面試題

A.創建表格CODE省略

註明:學生表PK stu_id 課程表pk cos_id 分數表PK enrollment_id FK stu_id,cos_id

B.插入數據code省略

C.Query

  1. select s.stu_id,stu_name,count(cos_id) from student s,enrollments e where s.stu_id = e.stu_id and e.grade>60 group by s.stu_id,stu_name;

  2. select e.stu_id,s.stu_name,c.cos_name from student s,enrollments e,course c

    where s.stu_id = e.stu_id

    and e.cos_id = c.cos_id

    and c.cos_name = 'CHINESE'

    and s.stu_name like 'W%';

  3. select stu_id,stu_name from (select e.stu_id,stu_name,cos_name from enrollments e,student s,course c

    where s.stu_id = e.stu_id

    and e.cos_id = c.cos_id

    and c.cos_name IN ('CHINESE','MUSIC'))

    group by stu_id,stu_name

    having count(cos_name) = 2

  4. select distinct e.cos_id,c.cos_name,count(e.stu_id) stu_count,count(e.stu_id)-NVL(A.FAIL,0) upscore,(count(e.stu_id)-NVL(A.FAIL,0))/count(e.stu_id) rate from

    (select cos_id,count(stu_id) fail from enrollments where grade<60 group by cos_id) a,enrollments e,course c

    where e.cos_id = a.cos_id(+)

    and e.cos_id = c.cos_id

    group by e.cos_id,NVL(a.fail,0),c.cos_name;

  5. update student

    set avg_grade =(select avg(grade) X from enrollments group by stu_id

    having student.stu_id = enrollments.stu_id);

  6. select stu_id,avg(grade) from

    (select stu_id,cos_id,grade,row_number() over(partition by stu_id order by grade ) X from enrollments)

    group by stu_id

    having count(*)<=2

    UNION

    select A.stu_id,avg(A.grade)from

    (select stu_id,cos_id,grade,row_number() over(partition by stu_id order by grade ) X from enrollments) A,

    (select stu_id,count(*) c from

    (select stu_id,cos_id,grade,row_number() over(partition by stu_id order by grade ) X from enrollments)

    group by stu_id) B

    where A.stu_id = B.stu_id

    and A.x>1 and x<B.c

    group by A.stu_id,b.c

_________________________________________________

環境:oracle 10g/TOAD 以上代碼均通過測試,如有問題,請聯系,謝謝

⑼ 資料庫SQL查詢語句面試題

5.1
select a.username,b.deptname from users a,dept b where a.dept_id=b.id;

5.2
update users set dept_id='9' where dept_id='2';

5.3
select a.deptname,b.count_id from dept a,(select dept_id,count(id) as count_id from users group by dept_id having count(id)>1) b where a.id=b.dept_id;

5.4
select a.deptname,b.count_man,c.count_woman from dept a,(select dept_id,count(sex) as count_man from users where sex='男' group by dept_id) b,(select dept_id,count(sex) as count_woman from users where sex='女' group by dept_id) c where a.id=b.dept_id and a.id=c.dept_id;

5.5
添加歷史記錄表
create table history(
id number(8), -- 記錄編號
dept_id varchar2(5), -- 部門ID
user_id varchar2(5), -- 用戶ID
change_date date -- 變動日期
);

⑽ SQL 面試題

SELECT aa.日期, aa.數值, SUM(lj.數值) AS 累計
FROM 累積 lj INNER JOIN
(SELECT *
FROM 累積) aa ON lj.日期 <= aa.日期
WHERE (aa.日期 <= '2005-05-04') --日期可以變成時間段
GROUP BY aa.日期, aa.數值
ORDER BY aa.日期