用SQL*PLUS执行的结果如下:SQL> select *,(select count(*) from deeptree where parentid=id) as children 2 from deeptree 3 whrere id=parentid; select *,(select count(*) from deeptree where parentid=id) as children * ERROR 位于第 1 行: ORA-00923: 未找到预期 FROM 关键字错在何处?
select a.*, (select count(*) from deeptree where parentid = id) as children from deeptree a where a.id=a.parentid这样语法肯定是没错的,不过逻辑就有点问题了,count(*)求出来,却不分组,意义何在?
--查询 select * from scott.emp; --建表 create table temp_1 as select a.*, a.empno as empno2 from scott.emp a ; --在查询 select a.*, (select count(*) from temp_1 where empno = empno2) as children from temp_1 a where a.empno=a.empno2
新表中有一个原表的LINK字段未显示,而且也没有别名字段CHILDREN
2 from deeptree
3 whrere id=parentid;
select *,(select count(*) from deeptree where parentid=id) as children
*
ERROR 位于第 1 行:
ORA-00923: 未找到预期 FROM 关键字错在何处?
from deeptree a
where a.id=a.parentid这样语法肯定是没错的,不过逻辑就有点问题了,count(*)求出来,却不分组,意义何在?
select * from scott.emp;
--建表
create table temp_1 as select a.*, a.empno as empno2 from scott.emp a ;
--在查询
select a.*, (select count(*) from temp_1 where empno = empno2) as children
from temp_1 a
where a.empno=a.empno2