Apache AGE 图数据库使用指南

-- 创建 Apache AGE 扩展
CREATE EXTENSION IF NOT EXISTS age;

-- 将 ag_catalog 加入 search_path
SET search_path = ag_catalog, "$user", public;

-- 或永久设置（推荐）
ALTER DATABASE mydb SET search_path = ag_catalog, "$user", public;

-- 创建一个新图
SELECT create_graph('knowledge_graph');

-- 创建带标签和属性的节点
SELECT * FROM cypher('knowledge_graph', $$
    CREATE (n:Person {name: '张三', age: 30, role: 'Engineer'})
    RETURN n
$$) AS (node agtype);

-- 批量创建节点
SELECT * FROM cypher('knowledge_graph', $$
    CREATE (a:Person {name: '李四', role: 'Manager'}),
           (b:Company {name: '腾讯云', industry: 'Cloud'}),
           (c:Technology {name: 'PostgreSQL', type: 'Database'})
    RETURN a, b, c
$$) AS (a agtype, b agtype, c agtype);

-- 创建节点之间的关系
SELECT * FROM cypher('knowledge_graph', $$
    MATCH (p:Person {name: '张三'}), (c:Company {name: '腾讯云'})
    CREATE (p)-[r:WORKS_AT {since: '2020-01-01'}]->(c)
    RETURN r
$$) AS (rel agtype);

-- 创建使用关系
SELECT * FROM cypher('knowledge_graph', $$
    MATCH (p:Person {name: '张三'}), (t:Technology {name: 'PostgreSQL'})
    CREATE (p)-[r:USES {level: 'expert'}]->(t)
    RETURN r
$$) AS (rel agtype);

-- 查找所有 Person 节点
SELECT * FROM cypher('knowledge_graph', $$
    MATCH (n:Person)
    RETURN n.name, n.role
$$) AS (name agtype, role agtype);

-- 查找关系路径
SELECT * FROM cypher('knowledge_graph', $$
    MATCH (p:Person)-[r:WORKS_AT]->(c:Company)
    RETURN p.name, c.name, r.since
$$) AS (person agtype, company agtype, since agtype);

-- 多跳查询
SELECT * FROM cypher('knowledge_graph', $$
    MATCH (p:Person)-[:WORKS_AT]->(c:Company),
          (p)-[:USES]->(t:Technology)
    RETURN p.name, c.name, t.name
$$) AS (person agtype, company agtype, tech agtype);

-- 路径查询（2-3 跳）
SELECT * FROM cypher('knowledge_graph', $$
    MATCH path = (a:Person)-[*2..3]->(b)
    RETURN path
$$) AS (path agtype);

-- 更新节点属性
SELECT * FROM cypher('knowledge_graph', $$
    MATCH (p:Person {name: '张三'})
    SET p.age = 31
    RETURN p
$$) AS (node agtype);

-- 删除关系
SELECT * FROM cypher('knowledge_graph', $$
    MATCH (p:Person {name: '张三'})-[r:USES]->(t:Technology)
    DELETE r
$$) AS (result agtype);

-- 删除节点（需先删除关联的边）
SELECT * FROM cypher('knowledge_graph', $$
    MATCH (t:Technology {name: 'PostgreSQL'})
    DETACH DELETE t
$$) AS (result agtype);

-- 图查询结果与关系表联合
SELECT g.person_name, u.email, u.department
FROM (
    SELECT * FROM cypher('knowledge_graph', $$
        MATCH (p:Person)-[:WORKS_AT]->(c:Company {name: '腾讯云'})
        RETURN p.name AS person_name
    $$) AS (person_name agtype)
) g
JOIN users u ON u.name = g.person_name::text;

-- 构建产品知识图谱
SELECT create_graph('product_kg');

SELECT * FROM cypher('product_kg', $$
    CREATE (pg:Product {name: 'PostgreSQL', category: 'Database'}),
           (vec:Feature {name: '向量检索', desc: '基于 pgvector'}),
           (ai:Feature {name: 'AI 调用', desc: '基于 tencentdb_ai'}),
           (pg)-[:HAS_FEATURE]->(vec),
           (pg)-[:HAS_FEATURE]->(ai)
    RETURN pg, vec, ai
$$) AS (pg agtype, vec agtype, ai agtype);

-- 实体提取后存入图，检索时图 + 向量混合召回：
-- 1. 向量召回相关文档
-- 2. 从图中找到相关实体的关系链
-- 3. 将图上下文 + 文档内容一起送给大模型

-- 记录 Agent 之间的交互关系
SELECT * FROM cypher('agent_memory', $$
    CREATE (a1:Agent {name: 'Planner', role: 'planning'}),
           (a2:Agent {name: 'Researcher', role: 'research'}),
           (a1)-[:DELEGATES {task: '调研竞品', timestamp: '2026-01-15'}]->(a2)
    RETURN a1, a2
$$) AS (a1 agtype, a2 agtype);