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SQL基础
1.创建数据库:create database 数据库名(database-name)
2.删除数据库:drop database dbname
3.说明:备份 sql server
--创建 备份数据的 device
use master exec sp_addumpdevice ‘disk‘,‘testBack‘,‘c:\mssql7backup\MyNwind_1.dat‘
--开始 备份
BACKUP DATABASE pubs TO testBack
4.说明:创建新表
create table tabname(coll typel [not null] [primary key],col2 type2 [not null],...)
5.删除新表
drop table tabname
6.增加一个列
alter table tabname add column col type
7.添加/删除主键
alter table tabname add/drop primary key(col)
8.创建视图
create view viewname as select statement
删除视图
drop view viewname
9.简单的sql语句
选择:select * from table where 范围
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 table where field1 like ‘%value1%‘
排序:select * from table1 order by field1,field2 //默认排序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
SQL基础