SQL语句先前写的时候,很容易把一些特殊的用法忘记,我特此整理了一下SQL语句操作。 pge++Di
Ev2HGU [
G,<T/f
.{$
一、基础 RQB]/D\BO
1、说明:创建数据库 Gqcz<=/
CREATE DATABASE database-name L9ap(
2、说明:删除数据库 zT|)uP*
drop database dbname 9cx =@
3、说明:备份sql server >'5_Y]h4m|
--- 创建 备份数据的 device |*X*n*oI
USE master K+)%KP
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat' zYv#:>C8
--- 开始 备份 |Uk"
{
BACKUP DATABASE pubs TO testBack q;D+ai
4、说明:创建新表 F@!Td(r2
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..) qG/fE'(j&
根据已有的表创建新表: pdb1GDl0q
A:create table tab_new like tab_old (使用旧表创建新表) CGP3qHrXt
B:create table tab_new as select col1,col2... from tab_old definition only %?hsoj&k
5、说明:删除新表 m8JR@!t7
drop table tabname Ty@=yA17
6、说明:增加一个列 ,j ',x\
Alter table tabname add column col type H:JLAK
注:列增加后将不能删除。DB2中列加上后数据类型也不能改变,唯一能改变的是增加varchar类型的长度。 8dOo Q
7、说明:添加主键: Alter table tabname add primary key(col) =GBI0&U
说明:删除主键: Alter table tabname drop primary key(col) z6~
H:k1G%
8、说明:创建索引:create [unique] index idxname on tabname(col....) XJ+6FT/qss
删除索引:drop index idxname %77p5ctW
注:索引是不可更改的,想更改必须删除重新建。 @[?!s%*2
9、说明:创建视图:create view viewname as select statement nGf);U#K
删除视图:drop view viewname u@P[Vb
10、说明:几个简单的基本的sql语句 >Aq870n
选择:select * from table1 where 范围 cZ+7.oDu
插入:insert into table1(field1,field2) values(value1,value2) yag}fQ(XH
删除:delete from table1 where 范围 GOB(#vu
更新:update table1 set field1=value1 where 范围 4Kv[e]10(
查找:select * from table1 where field1 like '%value1%' ---like的语法很精妙,查资料! F;!2(sPS
排序:select * from table1 order by field1,field2 [desc] Q U
F$@)A
总数:select count as totalcount from table1 G02m/8g3
求和:select sum(field1) as sumvalue from table1 }o,z!_^PLQ
平均:select avg(field1) as avgvalue from table1 .LRxP#B
最大:select max(field1) as maxvalue from table1 3PUAH
最小:select min(field1) as minvalue from table1 /_-;zL
'QH1=$Su
b2&