选择：select * from table1 where 范围
插入：insert into table1(field1,field2)values(value1,value2)
删除：delete from table1 where 范围
更新：update table1 set field1=value1 where 范围
查找：select * from table1 where field1 like ‘%value1%’
select * from table1 where field1 isno null
排序：select * from table1 order by field1,field2 desc
总数：select count as totalcount from table1
SQL: select count (value) as Tname from table_name where name=’x’
求和：select sum(field1) as sumvalue from table1
SQL: select sum(value) from table1
平均：select avg(field1) as avgvalue from table1
SQL: select avg(value) from table1
最大：select max(field1) as maxvalue from table1
SQL: select max(value) from table1
最小：select min(field1) as minvalue from table1
SQL: select min(value) from table1