Oracle 分层查询 | 码农家园

Oracle Hierarchical Queries

我正在努力处理具有以下要求的查询：

表A

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ID Name Key

1 A1 Key1
2 A2 Key2
3 A3 Key3

表B

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ID A_ID NAME CONTAINER_A_ID
1 1 B1 NULL
2 1 B2 NULL
3 1 B3 2
4 2 B4 NULL
5 2 B5 NULL
6 3 B6 NULL
7 3 B7 NULL

表 A 中的 Key 列是唯一的

表B中的A_ID列是表A的外键

表 B 中的 CONTAINER_A_ID 列表示表 B 中的行可以是
容器，它包含由 CONTAINER_A_ID 值指示的其他数据行。

下面是例子：

输入参数为表A键列值，假设A.Key = \\'key1\\'，根据上述样本数据得出的结果为：

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A.ID A.NAME A.KEY B.ID B.A_ID B.NAME B.CONTAINER_A_ID
1 A1 KEY1 1 1 B1 NULL
1 A1 KEY1 2 1 B2 NULL
1 A1 KEY1 3 1 B3 2
2 A2 KEY2 4 2 B4 NULL
2 A2 KEY2 5 2 B5 NULL

如果输入参数是A.Key = \\'key2\\'，则结果为：

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A.ID A.NAME A.KEY B.ID B.A_ID B.NAME B.CONTAINER_A_ID
2 A2 KEY2 4 2 B4 NULL
2 A2 KEY2 5 2 B5 NULL

谢谢

相关讨论

这是用于分层查询

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with TableA as
(
select 1 id, 'A1' Name, 'Key1' key from dual union all
select 2, 'A2', 'Key2' from dual union all
select 3, 'A3', 'Key3' from dual
)
, tableb as
(
select 1 id, 1 a_id, 'B1' name , null CONTAINER_A_ID from dual union all
select 2 , 1 , 'B2' , null from dual union all
select 3 , 1 , 'B3' , 2 from dual union all
select 4 , 2 , 'B4' , null from dual union all
select 5 , 2 , 'B5' , null from dual union all
select 6 , 3 , 'B6' , null from dual union all
select 7 , 3 , 'B7' , null from dual

)
select
a.id, a.name, a.key, b.id, b.a_id, b.name, b.container_a_id
from
tableb b
left join
tablea a
on
a.id = b.a_id
start with
A.Key = 'Key1'
connect by
prior b.container_a_id = b.a_id;

如果您需要订购，请在末尾添加 order by a.id, b.id,a.name,...;。

这是在 Oracle 11g 上。

如果您专门寻找 CONNECT BY，我还不知道。

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drop table t1; drop table t2;
create table t1 (id int primary key, name char(5), key char(5));
create table t2 (id int primary key, a_id int, name char(5) , container int);

insert into t1 values (1, 'A1', 'K1');
insert into t1 values (2, 'A2', 'K2');
insert into t1 values (3, 'A3', 'K3');

insert into t2 values (1, 1, 'B1', null);
insert into t2 values (2, 1, 'B2', null);
insert into t2 values (3, 1, 'B3', 2);
insert into t2 values (4, 2, 'B4', null);
insert into t2 values (5, 2, 'B5', null);
insert into t2 values (6, 3, 'B6', null);
insert into t2 values (7, 3, 'B7', null);

with t(id, name, key, bid, aid, bname, con) as (
select a.id, a.name, a.key, b.id, b.a_id, b.name, b.container
from t1 a
inner join
t2 b
on a.id = b.a_id
where a.key = 'K1'
union all
select a.id, a.name, a.key, b.id, b.a_id, b.name, b.container
from t t
inner join
t1 a
on a.id = t.con
inner join
t2 b
on a.id = b.a_id
) select * from t;

enter

1	insert into t2 values (4, 2, 'B4', 3);

enter