一、基础
1.创建数据库
create database dbname
2.删除数据库
drop database dbname
3.备份sql server
--创建备份数据的device
use master
exec sp_addumpdevice 'disk' ,'testBack','c:\mssql7\backup\MyNwind_1.dat'
--开始备份
backup database pubs to testback
4.创建新表
create table tabname(col 1 type1[not null] [primary key],co2 type2[not null]...)
根据已有的表创建新表
A:create table tab_new like tab_old(使用旧表创建新表)
B:create table tab_new as select col1,col2... from tab_old definition only
5.删除新表
drop table tabname
6.增加一列
Alter table tabname add column col type
注:列增加后将不能删除。DB2中列加上数据后数据类型也不能变,唯一能改变的是增加varchar的长度
7.添加主键:Alter table tabname add primary key(col)
删除主键:Alter table tabname drop primary key (col)
8.创建索引:create [unique] index inxname on tabname(col....)
删除索引:drop index idxname
注:索引是不可更改的,想要更改必须删除重新建
9。创建视图:create view viewname as select statement
删除视图:drop view viewname
10.几个简单基本sql语句
选择:select * from table1 where 范围
插入:insert into table1(field1,field2) values(value1,value2)
删除:delete from table1 where 范围
更新:update table 1 set field1 = value1 where 范围
查找:select * from table1 where field1 like '%value1%' --like 的语法
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 talble1
平均:select avg(field1) as avgvalue from table1
最大:select max(field11) as maxvalue from table1
最小:select min(field1) as minvalue from table1
11.几个高级查询运算
A:UNION运算符
UNION运算符通过组合其他两个结果表