# 创建数据库
neo4j@neo4j> CREATE DATABASE fgedudb;

# 输出示例：
0 rows
ready to start consuming query results after 5 ms, query completed after 5 ms.

# 查看所有数据库
neo4j@neo4j> SHOW DATABASES;

+——————————————————————————————–+
| name | type | status | currentStatus | default | home | constituents | access |
+——————————————————————————————–+
| “neo4j” | “standard” | “online” | “online” | TRUE | TRUE | [] | “read-write” |
| “fgedudb” | “standard” | “online” | “online” | FALSE | FALSE | [] | “read-write” |
| “system” | “system” | “online” | “online” | FALSE | FALSE | [] | “read-write” |
+——————————————————————————————–+

3 rows
ready to start consuming query results after 5 ms, query completed after 5 ms.

# 切换到新数据库
neo4j@neo4j> :use fgedudb;
neo4j@fgedudb>

# 输出示例：
Created 1 nodes, Set 1 properties, Added 1 labels
ready to start consuming query results after 5 ms, query completed after 5 ms.

# 创建多个节点
neo4j@fgedudb> CREATE (p1:Person {name: ‘李四’, age: 28, city: ‘上海’}),
(p2:Person {name: ‘王五’, age: 35, city: ‘广州’}),
(p3:Person {name: ‘赵六’, age: 32, city: ‘深圳’});

# 创建带关系的节点
neo4j@fgedudb> CREATE (a:Person {name: ‘张三’})-[:KNOWS {since: 2020}]->(b:Person {name: ‘李四’});

# 查看所有节点
neo4j@fgedudb> MATCH (n) RETURN n LIMIT 10;

+—————————————————+
| n |
+—————————————————+
| (:Person {name: “张三”, age: 30, city: “北京”}) |
| (:Person {name: “李四”, age: 28, city: “上海”}) |
| (:Person {name: “王五”, age: 35, city: “广州”}) |
| (:Person {name: “赵六”, age: 32, city: “深圳”}) |
+—————————————————+

# 创建关系
neo4j@fgedudb> MATCH (a:Person {name: ‘张三’}), (b:Person {name: ‘王五’})
CREATE (a)-[:FRIEND {since: 2021}]->(b);

# 查看关系
neo4j@fgedudb> MATCH (a)-[r]->(b) RETURN a.name, type(r), b.name;

+————————————-+
| a.name | type(r) | b.name |
+————————————-+
| “张三” | “KNOWS” | “李四” |
| “张三” | “FRIEND” | “王五” |
+————————————-+

+——————-+
| p.name | p.age |
+——————-+
| “王五” | 35 |
| “赵六” | 32 |
+——————-+

# 关系查询
neo4j@fgedudb> MATCH (a:Person {name: ‘张三’})-[:KNOWS|FRIEND]->(b)
RETURN a.name, b.name;

+——————-+
| a.name | b.name |
+——————-+
| “张三” | “李四” |
| “张三” | “王五” |
+——————-+

# 多跳关系查询
neo4j@fgedudb> MATCH path = (a:Person)-[*1..3]-(b:Person)
RETURN path;

# 聚合查询
neo4j@fgedudb> MATCH (p:Person)
RETURN p.city, count(*) as count, avg(p.age) as avg_age;

+———————————–+
| p.city | count | avg_age |
+———————————–+
| “北京” | 1 | 30.0 |
| “上海” | 1 | 28.0 |
| “广州” | 1 | 35.0 |
| “深圳” | 1 | 32.0 |
+———————————–+

# 最短路径查询
neo4j@fgedudb> MATCH path = shortestPath((a:Person {name: ‘张三’})-[*]-(b:Person {name: ‘赵六’}))
RETURN path;

# 统计节点数量
neo4j@fgedudb> MATCH (n) RETURN count(n) as node_count;
+————+
| node_count |
+————+
| 4 |
+————+

# 输出示例：
Added 1 index.
ready to start consuming query results after 5 ms, query completed after 5 ms.

# 创建复合索引
neo4j@fgedudb> CREATE INDEX person_city_age_index FOR (p:Person) ON (p.city, p.age);

# 创建唯一约束
neo4j@fgedudb> CREATE CONSTRAINT person_name_unique FOR (p:Person) REQUIRE p.name IS UNIQUE;

# 查看所有索引
neo4j@fgedudb> SHOW INDEXES;

+————————————————————————–+
| id | name | state | type | uniqueness |
+————————————————————————–+
| 1 | “person_name_index” | “ONLINE” | “BTREE” | “NONUNIQUE” |
| 2 | “person_city_age_index”| “ONLINE”| “BTREE” | “NONUNIQUE” |
| 3 | “person_name_unique” | “ONLINE” | “BTREE” | “UNIQUE” |
+————————————————————————–+

# 使用索引查询
neo4j@fgedudb> MATCH (p:Person) WHERE p.name = ‘张三’ RETURN p;

# 查看查询计划
neo4j@fgedudb> EXPLAIN MATCH (p:Person) WHERE p.name = ‘张三’ RETURN p;