Oracle start with..Connect By prior..用法实例讲解
2014-05-21 10:26
573 查看
oracle中的select语句可以用START WITH...CONNECT BY PRIOR子句实现递归查询,connect by 是结构化查询中用到的,其基本语法是:
select ... from <TableName>
where < Conditional-1>
start with <Conditional-2>
connect by < Conditional-3>
;
<Conditional-1>:过滤条件,用于对返回的所有记录进行过滤。
<Conditional-2>:查询结果重起始根结点的限定条件。
<Conditional-3>:连接条件
数据组织结构如下图:
数据库表结构如下:
create table t2(
root_id number,
id number,
name varchar(5),
description varchar(10)
);
insert into t2(root_id,id,name,description) values(0,1,'a','aaa');
insert into t2(root_id,id,name,description) values(1,2,'a1','aaa1');
insert into t2(root_id,id,name,description) values(1,3,'a2','aaa2');
insert into t2(root_id,id,name,description) values(0,4,'b','bbb');
insert into t2(root_id,id,name,description) values(4,5,'b1','bbb1');
insert into t2(root_id,id,name,description) values(4,6,'b2','bbb2');
获取完整树:
select * from t2 start with root_id = 0 connect by prior id = root_id;
获取特定子树:
select * from t2 start with id = 1 connect by prior id = root_id;
select * from t2 start with id = 4 connect by prior id = root_id;
如果connect by prior中的prior被省略,则查询将不进行深层递归。
如:
select * from t2 start with root_id = 0 connect by id = root_id;
select * from t2 start with id = 1 connect by id = root_id;
如:
转载地址:http://www.360doc.com/content/11/0608/11/5287961_122421161.shtml
oracle中的select语句可以用START WITH...CONNECT BY PRIOR子句实现递归查询,connect by 是结构化查询中用到的,其基本语法是:
select ... from <TableName>
where < Conditional-1>
start with <Conditional-2>
connect by < Conditional-3>
;
<Conditional-1>:过滤条件,用于对返回的所有记录进行过滤。
<Conditional-2>:查询结果重起始根结点的限定条件。
<Conditional-3>:连接条件
数据组织结构如下图:
数据库表结构如下:
create table t2(
root_id number,
id number,
name varchar(5),
description varchar(10)
);
insert into t2(root_id,id,name,description) values(0,1,'a','aaa');
insert into t2(root_id,id,name,description) values(1,2,'a1','aaa1');
insert into t2(root_id,id,name,description) values(1,3,'a2','aaa2');
insert into t2(root_id,id,name,description) values(0,4,'b','bbb');
insert into t2(root_id,id,name,description) values(4,5,'b1','bbb1');
insert into t2(root_id,id,name,description) values(4,6,'b2','bbb2');
获取完整树:
select * from t2 start with root_id = 0 connect by prior id = root_id;
获取特定子树:
select * from t2 start with id = 1 connect by prior id = root_id;
select * from t2 start with id = 4 connect by prior id = root_id;
如果connect by prior中的prior被省略,则查询将不进行深层递归。
如:
select * from t2 start with root_id = 0 connect by id = root_id;
select * from t2 start with id = 1 connect by id = root_id;
如:
转载地址:http://www.360doc.com/content/11/0608/11/5287961_122421161.shtml
相关文章推荐
- oracle中START WITH ... CONNECT BY PRIOR的用法
- Oracle start with ... connect by prior 用法
- Oracle START WITH...CONNECT BY PRIOR的用法
- oracle 的start with connect by prior 的用法
- ORACLE start with… connect by prior 子句用法
- Oracle start with connect by prior 用法(递归查询树形结构)
- oracle中 sql语句:start with .. connect by prior.. 用法
- Oracle start with connect by prior 递归查询用法
- Oracle start with connect by prior 用法
- oracle中 sql语句:start with .. connect by prior.. 用法
- Oracle start with connect by prior 用法
- oracle 中的select ...connect by prior ...start with 及(+)的用法
- Oracle_start_with_connect_by_prior_用法
- oracle start with connect by prior 递归查询用法
- oracle start with connect by prior 用法
- oracle 中的select ...connect by prior ...start with 及(+)的用法
- Oracle start with ... connect by prior 用法
- Oracle_start_with_connect_by_prior_用法
- Oracle中START WITH...CONNECT BY PRIOR用法
- oracle 递归查询 start with connect by prior