请教一下这个视图的创建方法

[alfwolf]

有表a,b
需要创建视图c以实现c中的字段anum,bnum分别为a,b中的记录数目
谢谢

[sasacat]

create view c
as
select (select count(*) from a ) anum,(select count(*) from b ) bnum from dual

[waterfirer]

select (select count(*) from a) anum,(select count(*) from b) bnum from dual

[sasacat]

create view c
as
select (select count(*) from a ) anum,(select count(*) from b ) bnum from dual

[qiaozhiwei]

SQL> create view test_cou as
2 SELECT A.COU AS A表条数, B.COU AS B表条数
3 FROM (SELECT 1 AS id, COUNT(*) AS cou
4 FROM AAA_CSDN_1) A,
5 (SELECT 1 AS id, COUNT(*) AS cou
6 FROM AAAA_CSDN_2) B
7 WHERE A.ID = B.ID;

视图已建立。

SQL> select * from test_cou;

A表条数 B表条数
---------- ----------
5 3

SQL>

[xinpingf]

2楼的方法即间接又明了。

[xinpingf]

写错了，是简洁
TMD微软拼音

[alfwolf]

谢谢各位,那个dual是什么意思,查询多个表的记录数也可以吗?

[sasacat]

N个表的记录数都可以。DUAL是一个只有一行数据的系统表

[lizhaogui]

create view c
as
select (select count(*) from a ) anum,(select count(*) from b ) bnum from dual


OK!