sql查询语句

1、创建数据库

CREATE DATABASE database-name

2、删除数据库

drop database dbname

3、删除新表

drop table tabname

4、增加一个列

Alter table tabname add column col type

5、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

6、创建新表

create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..)

根据已有的表创建新表：

A：create table tab_new like tab_old (用旧表创建新表)

B：create table tab_new as select col1,col2… from tab_old definition only

其它答案

牛仔很忙2020-06-22 18:56:36

选择：select * from table1 where 范围

删除：delete from table1 where 范围

插入： table1(field1,field2) values(value1,value2)

更新：update table1 set field1=value1 where 范围

查找：select * from table1 where field1 like ’%value1%’ ---like的语法很精妙，查资料!

排序：select * from table1 order by field1,field2 [desc]

总数：select count as totalcount from table1

最大：select max(field1) as maxvalue from table1

最小：select min(field1) as minvalue from table1

求和：select sum(field1) as sumvalue from table1

平均：select avg(field1) as avgvalue from table1