标签:返回 数据 between phone -- apt 存在 min rownum
--创建视图 create[or replace] [force|--不管基表是否存在都创建视图。 noforce]--仅当基表存在时才创建视图(默认)。 view view [(alias[,alias]…)] as subquery--子查询,决定了视图对应的数据。 [with check option[constraint constraint]]--指明对视图操作时,必须满足子查询中的约束条件。 [with read only[constraint constraint]];--指明该视图为只读视图,不能修改。 --创建TOP-N视图 --内嵌视图有一种特殊的应用,称为Top-N-Analysis查询,通过使用伪列ROWNUM,为查询结果集排序,并返回符合条件的记录。 select[column_list],rownum from(select[column_list]from table order by top-n_column) where rownum<=n; --例1 select * from ( select employee_id,first_name,last_name,salary from employee order by salary desc )nested_order where rownum <= 5;--查询工资排在前1~5名的员工号,员工名,工资,及其工资排号。 --例2 select * from t_test4 where rownum <= 5;--也是可以的 --例3 select * from ( select rownum num,employee_id,first_name,last_name,salary from ( select employee_id,first_name,last_name,salary from employee order by salary desc · )nested_order1 )nested_order2 where num between 5 and 10;--查询工资排在前5~10名的员工号,员工名,工资,及其工资排号。 --那么问题来了,为什么内嵌查询可以rownum>1 --分页查询 --第一种方式 select * from ( select a.*, rownum as rn from css_bl_view a where capture_phone_num = ‘(1) 925-4604800‘ )b where b.rn between 6 and 10; --第二种方式 select * from css_bl_view a where capture_phone_num = ‘(1) 925-4604800‘ and rownum <= 10 minus select * from css_bl_view a where capture_phone_num = ‘(1) 925-4604800‘ and rownum <= 5; --第三种方式 select * from ( select a.*, rownum as rn from css_bl_view a where capture_phone_num = ‘(1) 925-4604800‘ and rownum <= 10 )b where b.rn > 5; --一个用rownum的小技巧 select decode(rownum-min_sno,0,a.owner,null) owner,decode(rownum-min_sno,0,1,rownum+1-min_sno) sno, a.name from (select * from t_test8 order by owner, name ) a, (select owner, min(rownum) min_sno from( select * from t_test8 order by owner, name) group by owner) b where a.owner=b.owner;
标签:返回 数据 between phone -- apt 存在 min rownum
原文地址:http://www.cnblogs.com/wangyonglong/p/7132963.html