community: Retry retriable errors in Neo4j (#26211)

Co-authored-by: Erick Friis <erick@langchain.dev>

libs/community/langchain_community/vectorstores/neo4j_vector.py

@@ -595,11 +595,8 @@ class Neo4jVector(VectorStore):
         query: str,
         *,
         params: Optional[dict] = None,
-        retry_on_session_expired: bool = True,
     ) -> List[Dict[str, Any]]:
-        """
-        This method sends a Cypher query to the connected Neo4j database
-        and returns the results as a list of dictionaries.
+        """Query Neo4j database with retries and exponential backoff.
 
         Args:
             query (str): The Cypher query to execute.
@@ -608,24 +605,38 @@ class Neo4jVector(VectorStore):
         Returns:
             List[Dict[str, Any]]: List of dictionaries containing the query results.
         """
-        from neo4j.exceptions import CypherSyntaxError, SessionExpired
+        from neo4j import Query
+        from neo4j.exceptions import Neo4jError
 
         params = params or {}
-        with self._driver.session(database=self._database) as session:
-            try:
-                data = session.run(query, params)
-                return [r.data() for r in data]
-            except CypherSyntaxError as e:
-                raise ValueError(f"Cypher Statement is not valid\n{e}")
-            except (
-                SessionExpired
-            ) as e:  # Session expired is a transient error that can be retried
-                if retry_on_session_expired:
-                    return self.query(
-                        query, params=params, retry_on_session_expired=False
+        try:
+            data, _, _ = self._driver.execute_query(
+                query, database=self._database, parameters_=params
+            )
+            return [r.data() for r in data]
+        except Neo4jError as e:
+            if not (
+                (
+                    (  # isCallInTransactionError
+                        e.code == "Neo.DatabaseError.Statement.ExecutionFailed"
+                        or e.code
+                        == "Neo.DatabaseError.Transaction.TransactionStartFailed"
                     )
-                else:
-                    raise e
+                    and "in an implicit transaction" in e.message
+                )
+                or (  # isPeriodicCommitError
+                    e.code == "Neo.ClientError.Statement.SemanticError"
+                    and (
+                        "in an open transaction is not possible" in e.message
+                        or "tried to execute in an explicit transaction" in e.message
+                    )
+                )
+            ):
+                raise
+        # Fallback to allow implicit transactions
+        with self._driver.session() as session:
+            data = session.run(Query(text=query), params)
+            return [r.data() for r in data]
 
     def verify_version(self) -> None:
         """