本篇文章給大家談?wù)剆ql，以及sql server 2008對(duì)應(yīng)的知識(shí)點(diǎn)，希望對(duì)各位有所幫助，不要忘了收藏本站喔。
sql是什么
SQL是英文Structured Query Language的縮寫形式，它的意思是表示結(jié)構(gòu)化查詢語言。SQL語言的主要功能就是同各種數(shù)據(jù)庫建立聯(lián)系。此外，SQL是被當(dāng)成為關(guān)系型數(shù)據(jù)庫管理系統(tǒng)的標(biāo)準(zhǔn)語言。其是由Microsoft開發(fā)和推廣的關(guān)系數(shù)據(jù)庫管理系統(tǒng)。
擴(kuò)展資料：
SQL Server的特點(diǎn)如下：
1、具有真正的客戶機(jī)和服務(wù)器體系結(jié)構(gòu)。
2、圖形化用戶界面，使系統(tǒng)管理和數(shù)據(jù)庫管理更加直觀。
3、豐富的編程接口工具，為用戶進(jìn)行程序設(shè)計(jì)提供了更大的選擇余地。
4、其完全集成，利用了NT的許多功能，如發(fā)送和接受消息等。
參考資料：SqlServer-百度百科
sql是什么？
SQL語言，是結(jié)構(gòu)化查詢語言(Structured Query Language)的簡(jiǎn)稱。SQL語言是一種數(shù)據(jù)庫查詢和程序設(shè)計(jì)語言，用于存取數(shù)據(jù)以及查詢、更新和管理關(guān)系數(shù)據(jù)庫系統(tǒng)；同時(shí)也是數(shù)據(jù)庫腳本文件的擴(kuò)展名。
什么是sql
分類: 電腦/网络 程序設(shè)計(jì) 其他編程語言
問題描述:
sql在access的用法
解析:
SQL是一種結(jié)構(gòu)化查詢語言即Structure Query Language
一般格式：
SELECT[DISTINCT]目標(biāo)列表達(dá)式…
FROM表名，查詢名……
[WHERE 條件表達(dá)式]
[GROUP BY列名1[HAVING條件表達(dá)式]
[ORDER BY列名2[ASC│DESC];
SELECT SNAME,SDEPT FROM STUDENT
SELECT SNO,CNO FROM 查詢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 '劉?'
SAGE LIKE '1#'
1按學(xué)生成績(jī)降序排序，成績(jī)相同按課程號(hào)排序
select * from sc order by grade desc,o
2安課程號(hào)排序，課程號(hào)相同按成績(jī)將需排列
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 o,count(*) from sc group by o
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 courseo = sco;
SELECT SNAME+SDEPT AS SNSD FROM STUDENT
1查詢信息系年齡在18到20之間的學(xué)生信息
SELECT *
FROM STUDENT
WHERE SDEPT='IS'AND SAGE BETWEEN 18 AND 20;
2查詢每門課程相應(yīng)的選課人數(shù)
SELECT CNO,COUNT(SNO)
FROM SC
GROUP BY CNO;
SELECT COUNT(*) FROM SC
3查詢每個(gè)學(xué)生不及格課程門數(shù)
SELECT CNO,COUNT(CNO)
FROM SC
WHERE GRADE60
GROUP BY SNO
4查詢成績(jī)?cè)?0到100份之間的每門課程的選修人數(shù)
SELECT CNO, COUNT( SNO)
FROM SC
WHERE GRADE BETWEEN 90 AND 100
GROUP BY CNO ;
5查詢姓名第二個(gè)字是“力”的學(xué)生姓名和所在系
SELECT SNAME,SDEPT
FROM STUDENT
WHERE SNAME LIKE "?力*";
6查詢沒有成績(jī)的學(xué)生學(xué)號(hào)和對(duì)應(yīng)的課程號(hào)
SELECT SNO,CNO
FROM SC
WHERE GRADE IS NULL;
7查詢數(shù)學(xué)系和信息系所有男學(xué)生的情況
SELECT *
FROM STUDENT
WHERE SDEPT ="IS" OR SDEPT= "MA" AND SSEX="男";
8查詢總成績(jī)大于200分的學(xué)生學(xué)號(hào)
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',AGE50
2.SELECT ENO,ENAME FROM EMP ,WORKS WHERE SALARY1000 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 SALARY1000
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 grade60
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 beeen 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
子查詢
概念：
分類：
引導(dǎo)謂詞：select from where sage(select sage from student where sdept='cs')
，=，
查詢和劉晨同在一個(gè)系學(xué)習(xí)的學(xué)生
SELECT S1.* FROM STUDENT S1,STUDENT S2 WHERE S2.SNAME='劉晨' AND S1.SDEPT=S2.SDEPT
SELECT *
FROM STUDENT
WHERE SDEPT=
(SELECT SDEPT
FROM STUDENT
WHERE SNAME='劉晨')
select sname from student where sdept=(select sdept from student where sname='劉晨')
in
查詢選修了數(shù)據(jù)庫課程的學(xué)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='數(shù)據(jù)庫'))
select sname ,sdept
from student
where sno in
(select sno
from sc
where o=
(select o
from course
where ame='數(shù)據(jù)庫'))
select sname ,sdept
from student,sc,course
where student.sno=sc.sno and sco=courseo and ame='數(shù)據(jù)庫'
查詢其他系比信息系任一學(xué)生年齡小的學(xué)生情況
any,all
any大于子查詢結(jié)果中的某個(gè)值(min()大于最小值）
all大于子查詢結(jié)果中的所有值(max()大于最大值）
any小于子查詢結(jié)果中的某個(gè)值(max()小于最大值）
all小于子查詢結(jié)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'
*** 查詢
并（UNION）、交、差
查詢既選修了1號(hào)課程又選修了2號(hào)課程的學(xué)生學(xué)號(hào)。
SELECT SNO FROM SC WHERE CNO=1 AND SNO IN(SELECT SNO FROM SC WHERE CNO=2)
exists
网络班
查詢選修了全部課程的學(xué)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))
查詢至少選修了01001選修的全部課程的學(xué)生號(hào)碼
select sno from sc where o in(select o 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='數(shù)據(jù)庫'))
更新查詢
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 )
刪除(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
sql是什么意思
結(jié)構(gòu)化查詢語言（Structured Query Language）簡(jiǎn)稱SQL，是一種特殊目的的編程語言，是一種數(shù)據(jù)庫查詢和程序設(shè)計(jì)語言，用于存取數(shù)據(jù)以及查詢、更新和管理關(guān)系數(shù)據(jù)庫系統(tǒng)。
結(jié)構(gòu)化查詢語言是高級(jí)的非過程化編程語言，允許用戶在高層數(shù)據(jù)結(jié)構(gòu)上工作。它不要求用戶指定對(duì)數(shù)據(jù)的存放方法，也不需要用戶了解具體的數(shù)據(jù)存放方式。
所以具有完全不同底層結(jié)構(gòu)的不同數(shù)據(jù)庫系統(tǒng)，可以使用相同的結(jié)構(gòu)化查詢語言作為數(shù)據(jù)輸入與管理的接口。結(jié)構(gòu)化查詢語言語句可以嵌套，這使它具有極大的靈活性和強(qiáng)大的功能。
SQL具有數(shù)據(jù)定義、數(shù)據(jù)操縱、數(shù)據(jù)查詢和數(shù)據(jù)控制的功能。
1、SQL數(shù)據(jù)定義功能：能夠定義數(shù)據(jù)庫的三級(jí)模式結(jié)構(gòu)，即外模式、全局模式和內(nèi)模式結(jié)構(gòu)。在SQL中，外模式又叫做視圖（View），全局模式簡(jiǎn)稱模式（Schema），內(nèi)模式由系統(tǒng)根據(jù)數(shù)據(jù)庫模式自動(dòng)實(shí)現(xiàn)，一般無需用戶過問。
2、SQL數(shù)據(jù)操縱功能：包括對(duì)基本表和視圖的數(shù)據(jù)插入、刪除和修改，特別是具有很強(qiáng)的數(shù)據(jù)查詢功能。
3、SQL的數(shù)據(jù)控制功能：主要是對(duì)用戶的訪問權(quán)限加以控制，以保證系統(tǒng)的安全性。
