Oracle Property Graph 让关系型数据也能用图的方式查询。本文用一组转账数据，走一遍建表、建图、单跳与多跳查询的完整流程，并整理 ORA-40954: unknown label 的常见原因。
01 | 准备测试表与数据
建议在空白 schema 中执行。若对象已存在，先手工删除或更换名称。
|-----------------------------------------------------------------|
| CREATE TABLE money_accounts ( |
| account_id NUMBER CONSTRAINT money_accounts_pk PRIMARY KEY, |
| account_name VARCHAR2(50) NOT NULL |
| ); |
| |
| CREATE TABLE money_transfers ( |
| transfer_id NUMBER CONSTRAINT money_transfers_pk PRIMARY KEY, |
| from_account_id NUMBER NOT NULL, |
| to_account_id NUMBER NOT NULL, |
| amount NUMBER(12,2), |
| transfer_time TIMESTAMP, |
| CONSTRAINT money_transfer_from_fk |
| FOREIGN KEY (from_account_id) |
| REFERENCES money_accounts(account_id), |
| CONSTRAINT money_transfer_to_fk |
| FOREIGN KEY (to_account_id) |
| REFERENCES money_accounts(account_id) |
| ); |
插入 6 个账户：
|-------------------------------------------------|
| INSERT INTO money_accounts VALUES (1, '账户A'); |
| INSERT INTO money_accounts VALUES (2, '账户B'); |
| INSERT INTO money_accounts VALUES (3, '账户C'); |
| INSERT INTO money_accounts VALUES (4, '账户D'); |
| INSERT INTO money_accounts VALUES (5, '账户E'); |
| INSERT INTO money_accounts VALUES (6, '账户F'); |
构造一条连续转账链，并增加一条捷径：
快捷路径
A
B
C
D
E
F
|--------------------------------------------------------------|
| INSERT INTO money_transfers |
| VALUES (101, 1, 2, 1000, TIMESTAMP '2026-09-01 09:00:00'); |
| INSERT INTO money_transfers |
| VALUES (102, 2, 3, 900, TIMESTAMP '2026-09-01 10:00:00'); |
| INSERT INTO money_transfers |
| VALUES (103, 3, 4, 800, TIMESTAMP '2026-09-01 11:00:00'); |
| INSERT INTO money_transfers |
| VALUES (104, 4, 5, 700, TIMESTAMP '2026-09-01 12:00:00'); |
| INSERT INTO money_transfers |
| VALUES (105, 5, 6, 600, TIMESTAMP '2026-09-01 13:00:00'); |
| -- B 直接转到 E，形成另一条路径 |
| INSERT INTO money_transfers |
| VALUES (106, 2, 5, 500, TIMESTAMP '2026-09-01 14:00:00'); |
| COMMIT; |
02 | 创建属性图
显式声明两个标签：ACCOUNT 是顶点标签，TRANSFER 是边标签。
|------------------------------------------|
| CREATE PROPERTY GRAPH money_graph |
| VERTEX TABLES ( |
| money_accounts |
| KEY (account_id) |
| LABEL account |
| PROPERTIES ( |
| account_id, |
| account_name |
| ) |
| ) |
| EDGE TABLES ( |
| money_transfers |
| KEY (transfer_id) |
| SOURCE KEY (from_account_id) |
| REFERENCES money_accounts (account_id) |
| DESTINATION KEY (to_account_id) |
| REFERENCES money_accounts (account_id) |
| LABEL transfer |
| PROPERTIES ( |
| transfer_id, |
| amount, |
| transfer_time |
| ) |
| ); |
未加双引号的标识符会被 Oracle 规范化为大写，因此 LABEL account 可以通过 IS ACCOUNT 匹配。
03 | 单跳查询
|--------------------------------------------------------|
| SELECT * |
| FROM GRAPH_TABLE( |
| money_graph |
| MATCH (a IS ACCOUNT)-[t IS TRANSFER]->(b IS ACCOUNT) |
| COLUMNS ( |
| a.account_id AS source_account, |
| a.account_name AS source_name, |
| t.amount AS amount, |
| b.account_id AS target_account, |
| b.account_name AS target_name |
| ) |
| ) |
| ORDER BY source_account, target_account; |
它应返回 6 条直接转账关系。
04 | 1～5 跳查询
|-----------------------------------------------------------|
| SELECT * |
| FROM GRAPH_TABLE( |
| money_graph |
| MATCH (a IS ACCOUNT)-[IS TRANSFER]->{1,5}(b IS ACCOUNT) |
| COLUMNS ( |
| a.account_id AS source_account, |
| a.account_name AS source_name, |
| b.account_id AS target_account, |
| b.account_name AS target_name |
| ) |
| ) |
| WHERE source_account = 1 |
| ORDER BY target_account; |
从账户 A 出发，可以匹配到：
- A→B：1 跳
- A→B→C：2 跳
- A→B→C→D：3 跳
- A→B→C→D→E：4 跳
- A→B→C→D→E→F：5 跳
- A→B→E：另一条 2 跳路径
- A→B→E→F：另一条 3 跳路径
因此 E 和 F 可能出现多次，因为查询匹配的是"路径"，而不只是去重后的终点。如果只想看可达账户，可以在外层去重：
|-----------------------------------------------------------|
| SELECT DISTINCT target_account, target_name |
| FROM GRAPH_TABLE( |
| money_graph |
| MATCH (a IS ACCOUNT)-[IS TRANSFER]->{1,5}(b IS ACCOUNT) |
| COLUMNS ( |
| a.account_id AS source_account, |
| b.account_id AS target_account, |
| b.account_name AS target_name |
| ) |
| ) |
| WHERE source_account = 1 |
| ORDER BY target_account; |
05 | ORA-40954 常见原因
① 把表名当成标签名
图定义是 LABEL account，正确匹配是 (a IS ACCOUNT)，而不是 (a IS MONEY_ACCOUNTS)。IS 后面填的是 Label，不是底层表名。
② 没有显式声明预期标签
如果图定义没有 LABEL account，却查询 (a IS ACCOUNT)，Oracle 就可能找不到该标签。建议在教学和生产 DDL 中显式声明 Label。
③ 双引号导致大小写敏感
若创建时写 LABEL "Account"，标签名就是大小写敏感的 Account，查询必须写 (a IS "Account")，(a IS ACCOUNT) 无法匹配。最佳实践是标签不使用双引号。
④ 标签存在，但元素类型用错
TRANSFER 只定义在边上，却写成 (a IS TRANSFER)；或 ACCOUNT 只定义在顶点上，却写成 -[e IS ACCOUNT]->，都会出现标签无法用于当前位置的问题。
快速定位是哪一个标签有问题
先单独测试顶点标签：
|----------------------------------------|
| SELECT * |
| FROM GRAPH_TABLE( |
| money_graph |
| MATCH (a IS ACCOUNT) |
| COLUMNS (a.account_id AS account_id) |
| ); |
再单独测试边标签：
|------------------------------------------|
| SELECT * |
| FROM GRAPH_TABLE( |
| money_graph |
| MATCH (a)-[t IS TRANSFER]->(b) |
| COLUMNS (t.transfer_id AS transfer_id) |
| ); |
第一个失败说明 ACCOUNT 标签有问题；第二个失败说明 TRANSFER 标签有问题。