select (select count(*) from a) anum,(select count(*) from b) bnum from dual
create view c as select (select count(*) from a ) anum,(select count(*) from b ) bnum from dual
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 3SQL>
写错了,是简洁 TMD微软拼音
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?
N个表的记录数都可以。DUAL是一个只有一行数据的系统表
create view c as select (select count(*) from a ) anum,(select count(*) from b ) bnum from dual OK!
as
select (select count(*) from a ) anum,(select count(*) from b ) bnum from dual
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 3SQL>
TMD微软拼音
as
select (select count(*) from a ) anum,(select count(*) from b ) bnum from dual
OK!