数据库操作
查询表中重复的记录(以name,及price为条件，两条以上同样的记录)
方法1：select name,price, count(*) as b from EXPORT_TABLE where b>1 group by name,price order by b desc
方法2：sqlstr="select price,isbn from EXPORT_TABLE group by price,isbn having count(*)>1
查询并统计表中ID号相同的LIB值
select sum(lib) as libup,book_id from EXPORT_TABLE group by book_id order by book_id desc
方法1：select name,price, count(*) as b from EXPORT_TABLE where b>1 group by name,price order by b desc
方法2：sqlstr="select price,isbn from EXPORT_TABLE group by price,isbn having count(*)>1
查询并统计表中ID号相同的LIB值
select sum(lib) as libup,book_id from EXPORT_TABLE group by book_id order by book_id desc
