數據庫sql語句有哪些呢?下面就讓我們一起來了解一下吧:
sql語句有很多,比較基本的sql語句有:
選擇:select * from table1 where 範圍
插入:insert into table1(field1,field2) values(value1,value2)
刪除:delete from table1 where 範圍
更新:update table1 set field1=value1 where 範圍
查找:select * from table1 where field1 like ’%value1%’
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
最小:select min(field1) as minvalue from table1
當然也還有其他的sql語句,具體介紹如下:
若是備份sql server
1、創建、備份數據的 device,示例代碼爲:
USE master
EXEC sp_addumpdevice 'disk', 'testBack', 'c:mssql7backupMyNwind_1.dat'
2、開始、備份,示例代碼爲:
BACKUP DATABASE pubs TO testBack
若是創建新表
示例代碼爲:
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..)
若是依照已有的表創建新表
示例代碼爲:
A:create table tab_new like tab_old (使用舊錶創建新表)
B:create table tab_new as select col1,col2… from tab_old definition only
若是刪除新表
示例代碼爲:
drop table tabname