一些简单的SQL语句
1.创建数据库：create database database-name
2.删除数据库：delete database database-name
3.选择:select * from table where ...
4.插入：insert into table(field1,field2) values(value1,value2)
5.更新：update table set field1=value1 where ...
6.删除：delete from table where 范围
7.查找：select * from table where field1 like '%value1%'
8.排序: select * from table where order by field1,field2 [desc]
9.总数：select count as totalcount from table
10.求和：select sum(field1) as sumvalue from table
11.平均：select avg(field1) as avgvalue from table
12.最大：select max(field1) as maxvalue from table
13.最小：select min(field1) as minvalue from table
14.备份数据库：backup database database-name to disk
15.创建新表：create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..)
16.增加一列：Alter table tabname add column col type
17.添加主键：Alter table tabname add primary key(col)
18.删除主键：Alter table tabname drop primary key(col)
19.创建视图：create view viewname as select statement
20.删除视图：drop view viewname
