Prior to search, check if knowledge graph is empty

cognee/api/v1/search/search.py

@@ -1,13 +1,14 @@
 from uuid import UUID
 from typing import Union, Optional, List, Type
 
+from cognee.infrastructure.databases.graph import get_graph_engine
 from cognee.modules.engine.models.node_set import NodeSet
 from cognee.modules.users.models import User
 from cognee.modules.search.types import SearchResult, SearchType, CombinedSearchResult
 from cognee.modules.users.methods import get_default_user
 from cognee.modules.search.methods import search as search_function
 from cognee.modules.data.methods import get_authorized_existing_datasets
-from cognee.modules.data.exceptions import DatasetNotFoundError
+from cognee.modules.data.exceptions import DatasetNotFoundError, SearchOnEmptyGraphError
 
 
 async def search(
@@ -175,6 +176,15 @@ async def search(
         if not datasets:
             raise DatasetNotFoundError(message="No datasets found.")
 
+    graph_engine = await get_graph_engine()
+    edges_count = await graph_engine.count_edges()
+    nodes_count = await graph_engine.count_nodes()
+
+    if nodes_count == 0 or edges_count == 0:
+        raise SearchOnEmptyGraphError(
+            message="Knowledge graph is empty, please ensure data is added and cognified."
+        )
+
     filtered_search_results = await search_function(
         query_text=query_text,
         query_type=query_type,

cognee/modules/data/exceptions/__init__.py

@@ -9,4 +9,5 @@ from .exceptions import (
     UnauthorizedDataAccessError,
     DatasetNotFoundError,
     DatasetTypeError,
+    SearchOnEmptyGraphError,
 )

cognee/modules/data/exceptions/exceptions.py

@@ -35,6 +35,16 @@ class DatasetNotFoundError(CogneeValidationError):
         super().__init__(message, name, status_code)
 
 
+class SearchOnEmptyGraphError(CogneeValidationError):
+    def __init__(
+        self,
+        message: str = "Knowledge graph is empty, please ensure data is added and cognified.",
+        name: str = "SearchOnEmptyGraphError",
+        status_code=status.HTTP_400_BAD_REQUEST,
+    ):
+        super().__init__(message, name, status_code)
+
+
 class DatasetTypeError(CogneeValidationError):
     def __init__(
         self,