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SQLServer基础语法实例应用（一）

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Jun 07, 2016 pm 02:53 PM

sqlserverBaseExampleapplicationgrammar

一、基础1、说明：创建数据库 ? 1 CREATE DATABASE database-name 2、说明：删除数据库 ? 1 DROP DATABASE database-name 3、说明：备份数据库 ? 1 2 3 4 5 USE master -- 创建备份数据的 device EXEC sp_addumpdevice 'disk', 'cc_jz', 'd:cc_jz.dat' --

一、基础 1、说明：创建数据库

CREATE DATABASE database-name

2、说明：删除数据库

DROP DATABASE database-name

3、说明：备份数据库

USE master

-- 创建备份数据的 device

EXEC sp_addumpdevice 'disk', 'cc_jz', 'd:cc_jz.dat'

-- 开始备份

BACKUP DATABASE cc_jz TO cc_jz

4、说明：创建新表

create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..)

--> 测试数据：[a]

if object_id('[a]') is not null drop table [a]

create table [a]([ID] int,[品名] varchar(6),[入库数量] int,[入库时间] datetime)

insert [a]

select 1,'矿泉水',100,'2013-01-02' union all

select 2,'方便面',60,'2013-01-03' union all

select 3,'方便面',50,'2013-01-03' union all

select 4,'矿泉水',80,'2013-01-04' union all

select 5,'方便面',50,'2013-01-05'

select * from a

ID 品名入库数量入库时间

----------- ------ ----------- -----------------------

1 矿泉水 100 2013-01-02 00:00:00.000

2 方便面 60 2013-01-03 00:00:00.000

3 方便面 50 2013-01-03 00:00:00.000

4 矿泉水 80 2013-01-04 00:00:00.000

5 方便面 50 2013-01-05 00:00:00.000

(5 行受影响)

5、说明：删除新表

drop table tabname

6、说明：增加一个列

Alter table tabname add column col type

Alter table a add col int

select * from a

ID 品名入库数量入库时间 col

----------- ------ ----------- ----------------------- -----------

1 矿泉水 100 2013-01-02 00:00:00.000 NULL

2 方便面 60 2013-01-03 00:00:00.000 NULL

3 方便面 50 2013-01-03 00:00:00.000 NULL

4 矿泉水 80 2013-01-04 00:00:00.000 NULL

5 方便面 50 2013-01-05 00:00:00.000 NULL

(5 行受影响)

7、说明：添加主键：

Alter table tabname add primary key(col)

说明：删除主键：

Alter table tabname drop primary key(col)

8、说明：创建索引：

create [unique] index idxname on tabname(col….)

删除索引：

drop index idxname

注：索引是不可更改的，想更改必须删除重新建。

9、说明：创建视图：

create view viewname as select statement

删除视图：

drop view viewname

10、说明：几个简单的基本的sql语句

--选择：

select * from table1

--插入：

insert into table1(field1,field2) values(value1,value2)

--删除：

delete from table1 --where 范围

--更新：

update table1 set field1=value1 --where 范围

--查找：

select * from table1 where field1 like '%value1%'

--排序：

select * from table1 order by field1,field2 [desc]

--总数：

select count as totalcount from table1

--求和：

select sum(field1) as sumvalue from table1

--平均：

select avg(field1) as avgvalue from table1

--最大：

select max(field1) as maxvalue from table1

--最小：

select min(field1) as minvalue from table1

11、说明：几个高级查询运算词

A： UNION/UNION ALL 运算符

UNION 运算符通过组合其他两个结果表（例如 TABLE1 和 TABLE2）并消去表中任何重复行而派生出一个结果表。

当 ALL 随 UNION 一起使用时（即 UNION ALL），不消除重复行。两种情况下，派生表的每一行不是来自 TABLE1 就是来自 TABLE2。

--> 测试数据：[a]

if object_id('[a]') is not null drop table [a]

create table [a]([ID] int)

insert [a]

select 1 union all

select 2 union all

select 3 union all

select null

select * from a

(5 行受影响)

-----------

NULL

(5 行受影响)

--> 测试数据：[b]

if object_id('[b]') is not null drop table [b]

create table [b]([ID] int)

insert [b]

select 1 union all

select 2 union all

select 4 union all

select null

select * from b

(5 行受影响)

-----------

NULL

(5 行受影响)

--合并去重

select * from a

union

select * from b

-----------

NULL

(5 行受影响)

--合并不去重

select * from a

union all

select * from b

-----------

NULL

(10 行受影响)

B： EXCEPT 运算符

EXCEPT 运算符通过包括所有在 TABLE1 中但不在 TABLE2 中的行并消除所有重复行而派生出一个结果表。

注意：根本没有EXCEPT ALL 的用法；网上很多文章里写有EXCEPT ALL ，实际上是错误的。（测试SQL Server 2000 2005 2008R2 2012都不好用）

--> 测试数据：[a]

if object_id('[a]') is not null drop table [a]

create table [a]([ID] int)

insert [a]

select 1 union all

select 2 union all

select 3 union all

select null

select * from a

(5 行受影响)

-----------

NULL

(5 行受影响)

--> 测试数据：[b]

if object_id('[b]') is not null drop table [b]

create table [b]([ID] int)

insert [b]

select 1 union all

select 2 union all

select 4 union all

select null

select * from b

(5 行受影响)

-----------

NULL

(5 行受影响)

--取两表不同数据并去重

select * from a

EXCEPT

select * from b

-----------

(1 行受影响)

C： INTERSECT 运算符

INTERSECT 运算符通过只包括 TABLE1 和 TABLE2 中都有的行并消除所有重复行而派生出一个结果表。

注意：根本没有INTERSECT ALL 的用法；网上很多文章里写有INTERSECT ALL ，实际上是错误的。（测试SQL Server 2000 2005 2008R2 2012都不好用）

--> 测试数据：[a]

if object_id('[a]') is not null drop table [a]

create table [a]([ID] int)

insert [a]

select 1 union all

select 2 union all

select 3 union all

select null

select * from a

(5 行受影响)

-----------

NULL

(5 行受影响)

--> 测试数据：[b]

if object_id('[b]') is not null drop table [b]

create table [b]([ID] int)

insert [b]

select 1 union all

select 2 union all

select 4 union all

select null

select * from b

(5 行受影响)

-----------

NULL

(5 行受影响)

--取两表相同数据并去重

select * from a

INTERSECT

select * from b

-----------

NULL

(3 行受影响)

12、说明：使用外连接
A、left （outer） join：
左外连接（左连接）：结果集几包括连接表的匹配行，也包括左连接表的所有行。

SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c

--> 测试数据：[a]

if object_id('[a]') is not null drop table [a]

create table [a]([ID] int)

insert [a]

select 1 union all

select 2 union all

select 3 union all

select null

select * from a

(5 行受影响)

-----------

NULL

(5 行受影响)

--> 测试数据：[b]

if object_id('[b]') is not null drop table [b]

create table [b]([ID] int)

insert [b]

select 1 union all

select 2 union all

select 4 union all

select null

select * from b

(5 行受影响)

-----------

NULL

(5 行受影响)

select a.*,b.* from a a LEFT JOIN b b ON a.id= b.id

ID ID

----------- -----------

1 1

2 2

3 NULL

NULL NULL

(6 行受影响)

B：right （outer） join:

右外连接(右连接)：结果集既包括连接表的匹配连接行，也包括右连接表的所有行。

--> 测试数据：[a]

if object_id('[a]') is not null drop table [a]

create table [a]([ID] int)

insert [a]

select 1 union all

select 2 union all

select 3 union all

select null

select * from a

(5 行受影响)

-----------

NULL

(5 行受影响)

--> 测试数据：[b]

if object_id('[b]') is not null drop table [b]

create table [b]([ID] int)

insert [b]

select 1 union all

select 2 union all

select 4 union all

select null

select * from b

(5 行受影响)

-----------

NULL

(5 行受影响)

select a.*,b.* from a a RIGHT JOIN b b ON a.id= b.id

ID ID

----------- -----------

1 1

2 2

NULL 4

NULL NULL

(6 行受影响)

C：full/cross （outer） join：

全外连接：不仅包括符号连接表的匹配行，还包括两个连接表中的所有记录。

--> 测试数据：[a]

if object_id('[a]') is not null drop table [a]

create table [a]([ID] int)

insert [a]

select 1 union all

select 2 union all

select 3 union all

select null

select * from a

(5 行受影响)

-----------

NULL

(5 行受影响)

--> 测试数据：[b]

if object_id('[b]') is not null drop table [b]

create table [b]([ID] int)

insert [b]

select 1 union all

select 2 union all

select 4 union all

select null

select * from b

(5 行受影响)

-----------

NULL

(5 行受影响)

select a.*,b.* from a a FULL JOIN b b ON a.id= b.id

ID ID

----------- -----------

1 1

2 2

3 NULL

NULL NULL

NULL 4

NULL NULL

(8 行受影响)

Statement

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