Oracle sql 对具有图节点的 table 数据进行分层或递归查询

Question

这是我的 table "graphtable" 具有图形节点。每个元组代表一个无向边。

╔═════════╦═════════╗
║ NODEONE ║ NODETWO ║
╠═════════╬═════════╣
║ A       ║ A       ║
║ A       ║ A       ║
║ A       ║ B       ║
║ A       ║ B       ║
║ A       ║ A       ║
║ C       ║ D       ║
║ C       ║ A       ║
║ D       ║ E       ║
║ A       ║ E       ║
║ D       ║ A       ║
║ G       ║ K       ║
║ G       ║ G       ║
║ K       ║ K       ║
║ K       ║ L       ║
║ L       ║ M       ║
║ Y       ║ M       ║
║ G       ║ L       ║
║ G       ║ L       ║
║ X       ║ Z       ║
║ D       ║ D       ║
║ I       ║ I       ║
╚═════════╩═════════╝

如你所见，这个table中有四个不同的无向图。

节点（A、B、C、D、E）
节点（L、K、G、M、Y）
节点数（一）
节点（X,Z）

我尝试了类似于下面发布的查询；

select nodeone,nodetwo
from
graphtable
start with NODEONE='D'
connect by nocycle prior nodeone=nodetwo

我也可以使用递归查询来遍历图形。

但是，如果我从那个特定图[=40=中的任何节点开始，我需要获取特定图中涉及的所有元组].但是，我的任何查询都没有得到该结果。

从nodeone='A'开始；似乎 return 所有边缘，但边缘 'D-D' 不存在。从 nodeone='D' 开始；似乎 return 与之前的结果相去甚远。

请帮忙.. 我提前感谢任何帮助。谢谢。

Answer 1

Each tuple represents an undirected edge.

您没有将其视为无向边 - 您将其视为有向边，因为您只检查 prior nodeone=nodetwo 并且不检查当前边的任一端是否可以匹配前一个边。

SQL Fiddle

Oracle 11g R2 架构设置:

CREATE TABLE graphtable ( NODEONE, NODETWO ) AS
  SELECT 'A', 'A' FROM DUAL UNION ALL
  SELECT 'A', 'A' FROM DUAL UNION ALL
  SELECT 'A', 'B' FROM DUAL UNION ALL
  SELECT 'A', 'B' FROM DUAL UNION ALL
  SELECT 'A', 'A' FROM DUAL UNION ALL
  SELECT 'C', 'D' FROM DUAL UNION ALL
  SELECT 'C', 'A' FROM DUAL UNION ALL
  SELECT 'D', 'E' FROM DUAL UNION ALL
  SELECT 'A', 'E' FROM DUAL UNION ALL
  SELECT 'D', 'A' FROM DUAL UNION ALL
  SELECT 'G', 'K' FROM DUAL UNION ALL
  SELECT 'G', 'G' FROM DUAL UNION ALL
  SELECT 'K', 'K' FROM DUAL UNION ALL
  SELECT 'K', 'L' FROM DUAL UNION ALL
  SELECT 'L', 'M' FROM DUAL UNION ALL
  SELECT 'Y', 'M' FROM DUAL UNION ALL
  SELECT 'G', 'L' FROM DUAL UNION ALL
  SELECT 'G', 'L' FROM DUAL UNION ALL
  SELECT 'X', 'Z' FROM DUAL UNION ALL
  SELECT 'D', 'D' FROM DUAL UNION ALL
  SELECT 'I', 'I' FROM DUAL;

查询 1:

SELECT DISTINCT
       nodeone,
       nodetwo,
       rowid    -- Included as a unique id to differentiate edges with the
                -- same start/end points.
FROM   graphtable
START WITH NODEONE = 'D'
CONNECT BY NOCYCLE
   PRIOR nodeone IN ( nodeone, nodetwo )
OR PRIOR nodetwo IN ( nodeone, nodetwo )
ORDER SIBLINGS BY nodeone, nodetwo

Results:

| NODEONE | NODETWO |                     ROWID |
|---------|---------|---------------------------|
|       A |       A | oracle.sql.ROWID@57528909 |
|       A |       A | oracle.sql.ROWID@3d7f5c9c |
|       A |       A | oracle.sql.ROWID@777a44ea |
|       A |       B | oracle.sql.ROWID@1ca773d6 |
|       A |       B | oracle.sql.ROWID@5f7ebb8a |
|       A |       E | oracle.sql.ROWID@18229745 |
|       C |       A | oracle.sql.ROWID@3d5acdbf |
|       C |       D | oracle.sql.ROWID@1ac42001 |
|       D |       A | oracle.sql.ROWID@30cc6a38 |
|       D |       D | oracle.sql.ROWID@3cd85bdb |
|       D |       E | oracle.sql.ROWID@57845eca |

Oracle sql 对具有图节点的 table 数据进行分层或递归查询

Oracle sql hierarchical or recursive query on table data with graph nodes

sql

oracle

graph-theory

hierarchical-query