添加选取Neo4j指定数据库功能的支持

lightrag/kg/neo4j_impl.py

@@ -1,18 +1,16 @@
 import asyncio
+import inspect
 import os
 from dataclasses import dataclass
 from typing import Any, Union, Tuple, List, Dict
-import inspect
+
-from lightrag.utils import logger
-from ..base import BaseGraphStorage
 from neo4j import (
     AsyncGraphDatabase,
     exceptions as neo4jExceptions,
     AsyncDriver,
     AsyncManagedTransaction,
+    GraphDatabase
 )
-
-
 from tenacity import (
     retry,
     stop_after_attempt,
@@ -20,6 +18,9 @@ from tenacity import (
     retry_if_exception_type,
 )
 
+from lightrag.utils import logger
+from ..base import BaseGraphStorage
+
 
 @dataclass
 class Neo4JStorage(BaseGraphStorage):
@@ -38,10 +39,38 @@ class Neo4JStorage(BaseGraphStorage):
         URI = os.environ["NEO4J_URI"]
         USERNAME = os.environ["NEO4J_USERNAME"]
         PASSWORD = os.environ["NEO4J_PASSWORD"]
+        DATABASE = os.environ.get(
+            'NEO4J_DATABASE')  # If this param is None, the home database will be used. If it is not None, the specified database will be used.
+        self._DATABASE = DATABASE
         self._driver: AsyncDriver = AsyncGraphDatabase.driver(
             URI, auth=(USERNAME, PASSWORD)
         )
-        return None
+        _database_name = "home database" if DATABASE is None else f"database {DATABASE}"
+        with GraphDatabase.driver(URI, auth=(USERNAME, PASSWORD)) as _sync_driver:
+            try:
+                with _sync_driver.session(database=DATABASE) as session:
+                    try:
+                        session.run('MATCH (n) RETURN n LIMIT 0')
+                        logger.info(f"Connected to {DATABASE} at {URI}")
+                    except neo4jExceptions.ServiceUnavailable as e:
+                        logger.error(f"{DATABASE} at {URI} is not available".capitalize())
+                        raise e
+            except neo4jExceptions.AuthError as e:
+                logger.error(f"Authentication failed for {DATABASE} at {URI}")
+                raise e
+            except neo4jExceptions.ClientError as e:
+                if e.code == 'Neo.ClientError.Database.DatabaseNotFound':
+                    logger.info(f"{DATABASE} at {URI} not found. Try to create specified database.".capitalize())
+                try:
+                    with _sync_driver.session() as session:
+                        session.run(f'CREATE DATABASE `{DATABASE}` IF NOT EXISTS')
+                        logger.info(f"{DATABASE} at {URI} created".capitalize())
+                except neo4jExceptions.ClientError as e:
+                    if e.code == "Neo.ClientError.Statement.UnsupportedAdministrationCommand":
+                        logger.warning(
+                            "This Neo4j instance does not support creating databases. Try to use Neo4j Desktop/Enterprise version or DozerDB instead.")
+                    logger.error(f"Failed to create {DATABASE} at {URI}")
+                    raise e
 
     def __post_init__(self):
         self._node_embed_algorithms = {
@@ -63,7 +92,7 @@ class Neo4JStorage(BaseGraphStorage):
     async def has_node(self, node_id: str) -> bool:
         entity_name_label = node_id.strip('"')
 
-        async with self._driver.session() as session:
+        async with self._driver.session(database=self._DATABASE) as session:
             query = (
                 f"MATCH (n:`{entity_name_label}`) RETURN count(n) > 0 AS node_exists"
             )
@@ -78,7 +107,7 @@ class Neo4JStorage(BaseGraphStorage):
         entity_name_label_source = source_node_id.strip('"')
         entity_name_label_target = target_node_id.strip('"')
 
-        async with self._driver.session() as session:
+        async with self._driver.session(database=self._DATABASE) as session:
             query = (
                 f"MATCH (a:`{entity_name_label_source}`)-[r]-(b:`{entity_name_label_target}`) "
                 "RETURN COUNT(r) > 0 AS edgeExists"
@@ -91,7 +120,7 @@ class Neo4JStorage(BaseGraphStorage):
             return single_result["edgeExists"]
 
     async def get_node(self, node_id: str) -> Union[dict, None]:
-        async with self._driver.session() as session:
+        async with self._driver.session(database=self._DATABASE) as session:
             entity_name_label = node_id.strip('"')
             query = f"MATCH (n:`{entity_name_label}`) RETURN n"
             result = await session.run(query)
@@ -108,7 +137,7 @@ class Neo4JStorage(BaseGraphStorage):
     async def node_degree(self, node_id: str) -> int:
         entity_name_label = node_id.strip('"')
 
-        async with self._driver.session() as session:
+        async with self._driver.session(database=self._DATABASE) as session:
             query = f"""
                 MATCH (n:`{entity_name_label}`)
                 RETURN COUNT{{ (n)--() }} AS totalEdgeCount
@@ -155,7 +184,7 @@ class Neo4JStorage(BaseGraphStorage):
         Returns:
             list: List of all relationships/edges found
         """
-        async with self._driver.session() as session:
+        async with self._driver.session(database=self._DATABASE) as session:
             query = f"""
             MATCH (start:`{entity_name_label_source}`)-[r]->(end:`{entity_name_label_target}`)
             RETURN properties(r) as edge_properties
@@ -186,7 +215,7 @@ class Neo4JStorage(BaseGraphStorage):
         query = f"""MATCH (n:`{node_label}`)
                 OPTIONAL MATCH (n)-[r]-(connected)
                 RETURN n, r, connected"""
-        async with self._driver.session() as session:
+        async with self._driver.session(database=self._DATABASE) as session:
             results = await session.run(query)
             edges = []
             async for record in results:
@@ -241,7 +270,7 @@ class Neo4JStorage(BaseGraphStorage):
             )
 
         try:
-            async with self._driver.session() as session:
+            async with self._driver.session(database=self._DATABASE) as session:
                 await session.execute_write(_do_upsert)
         except Exception as e:
             logger.error(f"Error during upsert: {str(e)}")
@@ -288,7 +317,7 @@ class Neo4JStorage(BaseGraphStorage):
             )
 
         try:
-            async with self._driver.session() as session:
+            async with self._driver.session(database=self._DATABASE) as session:
                 await session.execute_write(_do_upsert_edge)
         except Exception as e:
             logger.error(f"Error during edge upsert: {str(e)}")