探灵笔记等级: JSON在線解析

1、創建數據庫
CREATE DATABASE database-name

2、刪除數據庫
drop database dbname

3、備份sql server
--- 創建 備份數據的 device
USE master
EXEC sp_addumpdevice 'disk', 'testBack', 'c:\mssql7backup\MyNwind_1.dat'
--- 開始 備份
BACKUP DATABASE pubs TO testBack

4、創建新表
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..)

根據已有的表創建新表:
A:create table tab_new like tab_old (使用舊表創建新表)
B:create table tab_new as select col1,col2… from tab_old definition only

5、刪除新表
drop table tabname

6、增加一個列
Alter table tabname add column col type
注:列增加后將不能刪除。DB2中列加上后數據類型也不能改變,唯一能改變的是增加varchar類型的長度。

7、添加主鍵: Alter table tabname add primary key(col)
刪除主鍵: Alter table tabname drop primary key(col)

8、創建索引:create [unique] index idxname on tabname(col….)
刪除索引:drop index idxname
注:索引是不可更改的,想更改必須刪除重新建。

9、創建視圖:create view viewname as select statement
刪除視圖:drop view viewname

10、幾個簡單的基本的sql語句
選擇:select * from table1 where 范圍
插入:insert into table1(field1,field2) values(value1,value2)
刪除:delete from table1 where 范圍
更新:update table1 set field1=value1 where 范圍
查找:select * from table1 where field1 like ’%value1%’ ---like的語法很精妙,查資料!
排序:select * from table1 order by field1,field2 [desc]
總數: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?。簊elect min(field1) as minvalue from table1

工具導航地圖