基本语句：
select: select * from tableName where condition and condition and ...
insert: insert into tableName(column1, column2, ...) values(value1, value2)
delete: delete from tableName where conditions
update: update tableName set column1=value1, column2=value2, ... where conditions
提升：
模糊查询: select * from tableName where column like '%value%'
选择前N条记录：select top N * from tableName where condition and condition and ...
统计: select count(*) from tableName where conditions
排序: select * from tableName where column1 like '%value%' order by column2, column3, ... desc(降序) asc(升序)
求和: select sum(column) as name from tableName
平均: select avg(column) as name from tableName
最大值: select max(column) as name from tableName
最小值: select min(column) as name from tableName