Fix get_node error for PostgreSQL graph storage

lightrag/base.py

@@ -297,13 +297,13 @@ class BaseGraphStorage(StorageNameSpace, ABC):
 
     @abstractmethod
     async def get_node(self, node_id: str) -> dict[str, str] | None:
-        """Get an edge by its source and target node ids."""
+        """Get node by its label identifier, return only node properties"""
 
     @abstractmethod
     async def get_edge(
         self, source_node_id: str, target_node_id: str
     ) -> dict[str, str] | None:
-        """Get all edges connected to a node."""
+        """Get edge properties between two nodes"""
 
     @abstractmethod
     async def get_node_edges(self, source_node_id: str) -> list[tuple[str, str]] | None:

lightrag/kg/neo4j_impl.py

@@ -267,7 +267,7 @@ class Neo4JStorage(BaseGraphStorage):
                 raise
 
     async def get_node(self, node_id: str) -> dict[str, str] | None:
-        """Get node by its label identifier.
+        """Get node by its label identifier, return only node properties
 
         Args:
             node_id: The node label to look up

lightrag/kg/postgres_impl.py

@@ -1194,6 +1194,8 @@ class PGGraphStorage(BaseGraphStorage):
         return single_result["edge_exists"]
 
     async def get_node(self, node_id: str) -> dict[str, str] | None:
+        """Get node by its label identifier, return only node properties"""
+
         label = node_id.strip('"')
         query = """SELECT * FROM cypher('%s', $$
                      MATCH (n:base {entity_id: "%s"})
@@ -1202,7 +1204,7 @@ class PGGraphStorage(BaseGraphStorage):
         record = await self._query(query)
         if record:
             node = record[0]
-            node_dict = node["n"]
+            node_dict = node["n"]["properties"]
 
             return node_dict
         return None
@@ -1235,6 +1237,8 @@ class PGGraphStorage(BaseGraphStorage):
     async def get_edge(
         self, source_node_id: str, target_node_id: str
     ) -> dict[str, str] | None:
+        """Get edge properties between two nodes"""
+        
         src_label = source_node_id.strip('"')
         tgt_label = target_node_id.strip('"')