T-SQL修改表數據
INSERT語句
語法：
INSERT
[TOP(expression) [PERCENT]]
[INTO]
{ <object> | rowset_function_limited
[ WITH ( <Table_Hint_Limited> [ ...n ] ) ] /*指定表提示*/
| view_name } /*視圖名*/
{
[(column_list) ] /*指定列名*/
[<OUTPUT Clause> ]
{VALUES /*指定列名的取值*/
{DEFAULT | NULL | expression}[1…n]) /*列值的構成形式*/
|derived_table|execute_statement } } /*結果集*/
|DEFAULT VALUES /*所有列均取默認值*/
例子：
/*插入單個元組*/
/*向student表中插入一個學生記錄（‘200’，‘曾雷’，‘女’，‘1978-2-3’，‘05001’）*/
USE test
INSERT INTO student_1
VALUES(100,'曾雷','女','1995-2-3',20)
/*查詢student表，查看結果*/
select * from student_1
-----------------------------------------------------------------------------------
/*向student表中插入一個學生記錄（‘201’，‘孫浩’，‘男’，‘1977-8-4’，NULL）*/
INSERT INTO student_1(sno,sname,ssex,sbirthday,sage)
VALUES(200,'孫浩','男','1996-8-4',null)
select * from student_1
delete from student_1 where sno=200
INSERT INTO student_1(sno,sname,ssex,sbirthday)
VALUES(200,'孫浩','男','1996-8-4')
-----------------------------------------------------------------------------------
/*插入元組集合*/
/*將student_1表中的相關數據插入到student表中*/
select * from student
select * from student_1
insert into student(sno,sname,ssex,sage)
select sno,sname,ssex,sage
from student_1
/*向student表中添加兩個新生*/
INSERT INTO student_1(sno,sname,ssex,sbirthday,sage)
VALUES(300,'王明','男','1996-8-4',19),(400,'趙強','男','1996-4-1',19)
-----------------------------------------------------------------------------------
/*向自增列添加數據*/
create table testidentity(
id int identity,
words varchar(10))
insert into testidentity values('a') --標識列不指定
insert into testidentity values('b') --指定除了標識列外的列
set IDENTITY_INSERT testidentity on
insert into testidentity(id,words) values(10,'c') --指定標識列
set IDENTITY_INSERT testidentity off
insert into testidentity values('d')
select * from testidentityUPDATE語句
語法：
UPDATE｛table_name｜view_name｝
SET column_name = {expression | DEFAULT | NULL}[1…n]
where where_clause
例子：
/*將sc表中的成績小於60的加5。*/
UPDATE sc
SET grade=grade+5
WHERE grade<70
/*將張三選修1號課程的成績置零。*/
UPDATE sc
SET grade=0
WHERE cno=1 and sno in
(select sno from student where sname='張三')
/*將學號爲1的學生的姓名改爲張三十，年齡改小2歲。*/
UPDATE student
SET sname='張三十',sage=sage-2 --同時更新多列
WHERE sno=1
select * from student
-----------------------------------------------------------------------------------
/*使用top表達式*/
UPDATE top(2) student
SET sage=sage-2
UPDATE top(50) percent student
SET sage=sage-2DELETE語句
語法：
DELETE table_name
WHERE search_condition
例子：
/*刪除student表中學號爲200的記錄*/
select * from student
select * from sc
DELETE student
WHERE sno='200'
/*刪除張三的選修1號課程的選課記錄*/
DELETE sc
WHERE cno=1 and sno in
(select sno from student where sname='張三')
-----------------------------------------------------------------------------------
/*TRANCATE*/
/*TRUNCATE TABLE table_name*/
/*一次刪除表中所有數據，即清空表，
但表的結構及約束保持不變，且該操作不記錄日誌，無法恢復，使用時必須慬慎。*/
/*刪除student_1表中的記錄*/
TRUNCATE TABLE student_1
select * from student_1
T-SQL查詢數據
SELECT 語句語法：
SELECT select_list
[INTO new_table]
FROM table_source
[WHERE search_condition]
[GROUP BY group_by_expression]
[HAVING search_condition]
[ORDER BY order_expression [ASC | DESC]]
簡單查詢例子：
/*查詢列*/
/*查詢student表中所有記錄的sname、ssex和sage列*/
SELECT sname,ssex,sage
FROM student
/*查詢有選課記錄的課程cno*/
select distinct cno --避免重複項
from sc
/*查詢有85分以上成績的課程cno*/
SELECT DISTINCT cno
FROM sc
WHERE grade>85
/*查詢student表的所有記錄*/
SELECT *
FROM student
SELECT sno as '學號',sname as '姓名',ssex as '性別'
FROM student
/*返回部分結果top*/
select top(1) * from student
select top(1) * from student where ssex='女'
select top(1) with ties * from student order by sage
select top(50) percent * from student
/*計算列*/
select sno,sname,2015-sage as '出生年月' from student
select sno,cno,grade*1.1 from sc
-----------------------------------------------------
/*選擇查詢
查詢sc表中成績大於60的所有記錄*/
SELECT *
FROM sc
WHERE grade>60
/*查詢sc表中1號課程成績大於60的所有記錄*/
SELECT *
FROM sc
WHERE cno=2 and grade>60
/*查詢score表中成績在60～80之間的所有記錄*/
SELECT *
FROM sc
WHERE grade between 60 and 80
/*查詢sc表中成績爲85、86或88的記錄*/
SELECT *
FROM sc
WHERE grade in(85,86,88)
/*字符串匹配*/
/* % 匹配任意字符
_ 匹配單個字符
[] 匹配括號中的任意一個字符
[^]或[!]匹配沒有出現在括號中的單個字符
escape換碼字符 */
select * from student
/*查詢student表中姓張的或性別爲“女”的學生記錄*/
SELECT *
FROM student
WHERE sname like '張%'or ssex='女'
/*查詢student表中姓李的學生*/
SELECT *
FROM student
WHERE sname like '李%'
SELECT *
FROM student
WHERE sname like '[李]%'
SELECT *
FROM student
WHERE sname like '李_'
SELECT *
FROM student
WHERE sname like '[^李]%'
SELECT *
FROM student
WHERE sname not like '[李]%'
SELECT *
FROM student
WHERE sname like '%[四]%'
/*查詢sc表中沒成績的記錄*/
SELECT *
FROM sc
WHERE grade is null
SELECT *
FROM sc
WHERE grade is not null
/*查詢結果排序*/
SELECT *
FROM sc
order by grade
SELECT *
FROM sc
order by cno,grade desc
/*分組查詢*/
/*group by group_by_expression[with rollup|cube]*
having search_condition
with rollup 只返回第一個分組條件制定的列的統計行;
而with cube除返回group by制定的列外,還返回按組統計的行*/
SELECT cno,AVG(grade)
FROM sc
group by cno
SELECT cno,AVG(grade)
FROM sc
group by cno
having AVG(grade)>60
SELECT cno,tno,AVG(grade)
FROM sc
group by cno,tno
SELECT cno,tno,AVG(grade)
FROM sc
group by cno,tno with rollup
select AVG(grade)
from sc高級查詢例子：
/*嵌套查詢*/
use test
/*使用IN或NOT IN*/
select sname
from student
where sno in
(select sno
from sc
where cno=2)
select sname
from student
where sno not in
(select sno
from sc
where cno=2)
/*比較運算符的子查詢*/
select sno,grade
from sc sc1
where sc1.cno=1 and
sc1.grade=(select sc2.grade
from sc sc2
where sc2.cno=1 and sc2.sno=1)
select * from sc
select sno,grade
from sc sc1
where sc1.cno=1 and
sc1.grade>(select sc2.grade
from sc sc2
where sc2.cno=1 and sc2.sno=1)
select sno
from sc
where cno=1 and
grade>all(select grade from sc where sno=1)
select sno
from sc
where cno=1 and
grade>(select max(grade) from sc where sno=1)
select student.sno,sname,cno,grade
from sc as a,student
where student.sno=a.sno and --不相關子查詢
grade>(select avg(grade)
from sc b
where b.cno=a.cno)
/*exists*/
SELECT sname
FROM student
WHERE EXISTS
(SELECT *
FROM sc
WHERE student.sno=sc.sno and sc.cno=2)
SELECT sname
FROM student
WHERE not EXISTS
(SELECT *
FROM sc
WHERE student.sno=sc.sno and sc.cno=2)
/*多層嵌套查詢
查詢最高分的學生姓名*/
select *
from student
where not exists
(select *
from course
where not exists
(select *
from sc
where sc.sno=student.sno and sc.cno=course.cno))
select sname
from student
where sno in
(select sno
from sc
where grade=
(select max(grade)
from sc))
go
select * from sc
select * from student
/*DELETE、UPDATE和INSERT語句中的子查詢*/
------------------------------------------------------------
/*聯接查詢*/
use test
/*查詢學生的姓名，選課號及成績*/
select sname,cno,grade
from student,sc
where student.sno=sc.sno
select sname,cname,grade
from student,sc,course --多表連接
where student.sno=sc.sno and sc.cno=course.cno
select sname,cno,grade
from student inner join sc on(student.sno=sc.sno) --內連接
select student.sname,sc.cno,sc.grade
from student left join sc on (student.sno=sc.sno) --左向外連接
select student.sname,sc.cno,sc.grade
from student right join sc on (student.sno=sc.sno) --右向外連接
select student.sname,sc.cno,sc.grade
from student full outer join sc on (student.sno=sc.sno) --完全外部連接
select student.sno,sc.sno,sc.cno,sc.grade
from student cross join sc --交叉連接
select student.sno,sc.sno,sc.cno,sc.grade
from student cross join sc --帶限定條件的交叉連接
where student.sno<2
select c1.cno,c2.cname
from course c1,course c2 --自連接
where c1.cpno=c2.cno
--------------------------------------------------------------------------
/*無法使用ntext、text或image列上直接連接表，
但是使用substring函數在ntext、text或image列上間接聯接表，如*/
select *
from student join sc
on substring(student.mytext,1,2)=substring(sc.mytext,1,2)
------------------------------
/*使用UNION運算符組合多個結果
查詢所有作者和客戶的號碼和名稱*/
select sno,sname from student where sno=1
union
select sno,sname from student where sno=2
go
---------------------------
/*在查詢的基礎上創建新表
將查詢得到的學生學號、姓名、課程和分數輸入到新建的表score1中，
再顯示該新表的記錄*/
select student.sno,avg(grade) as 平均成績
into avggrade --該表自動生成
from student inner join sc on (student.sno=sc.sno)
group by student.sno
select * from avggrade
drop table avggrade博客園博客:欠扁的小籃子