fix: add full text search for neo4j db (#1095) (#1099)

* feat: add full_text_search for neo4j

* test: 改回去

---------

## Description

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implementation approach, and relevant context. List any dependencies
required for this change.

Related Issue (Required):  Fixes @issue_number

## Type of change

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- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to not work as expected)
- [ ] Refactor (does not change functionality, e.g. code style
improvements, linting)
- [ ] Documentation update

## How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide
instructions so we can reproduce. Please also list any relevant details
for your test configuration

- [ ] Unit Test
- [ ] Test Script Or Test Steps (please provide)
- [ ] Pipeline Automated API Test (please provide)

## Checklist

- [ ] I have performed a self-review of my own code | 我已自行检查了自己的代码
- [ ] I have commented my code in hard-to-understand areas |
我已在难以理解的地方对代码进行了注释
- [ ] I have added tests that prove my fix is effective or that my
feature works | 我已添加测试以证明我的修复有效或功能正常
- [ ] I have created related documentation issue/PR in
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## Reviewer Checklist
- [ ] closes #xxxx (Replace xxxx with the GitHub issue number)
- [ ] Made sure Checks passed
- [ ] Tests have been provided

Author: CaralHsi

src/memos/graph_dbs/neo4j.py

@@ -928,6 +928,26 @@ def search_by_embedding(
 
         return records
 
+    def search_by_fulltext(
+        self,
+        query_words: list[str],
+        top_k: int = 10,
+        scope: str | None = None,
+        status: str | None = None,
+        threshold: float | None = None,
+        search_filter: dict | None = None,
+        user_name: str | None = None,
+        filter: dict | None = None,
+        knowledgebase_ids: list[str] | None = None,
+        tsquery_config: str | None = None,
+        **kwargs,
+    ) -> list[dict]:
+        """
+        TODO: 实现 Neo4j 的关键词检索, 以兼容 TreeTextMemory 的 keyword/fulltext 召回路径.
+        目前先返回空列表, 避免切换到 Neo4j 后因缺失方法导致运行时报错.
+        """
+        return []
+
     def get_by_metadata(
         self,
         filters: list[dict[str, Any]],

src/memos/graph_dbs/neo4j_community.py

@@ -382,6 +382,26 @@ def search_by_embedding(
 
         return filtered_results
 
+    def search_by_fulltext(
+        self,
+        query_words: list[str],
+        top_k: int = 10,
+        scope: str | None = None,
+        status: str | None = None,
+        threshold: float | None = None,
+        search_filter: dict | None = None,
+        user_name: str | None = None,
+        filter: dict | None = None,
+        knowledgebase_ids: list[str] | None = None,
+        tsquery_config: str | None = None,
+        **kwargs,
+    ) -> list[dict]:
+        """
+        TODO: 实现 Neo4j Community 的关键词检索, 以兼容 TreeTextMemory 的 keyword/fulltext 召回路径.
+        目前先返回空列表, 避免切换到 Neo4j 后因缺失方法导致运行时报错.
+        """
+        return []
+
     def _normalize_date_string(self, date_str: str) -> str:
         """
         Normalize date string to ISO 8601 format for Neo4j datetime() function.

src/memos/memories/textual/tree_text_memory/retrieve/searcher.py

@@ -513,16 +513,22 @@ def _retrieve_from_keyword(
 
         id_to_score: dict[str, float] = {}
         for scope in scopes:
-            hits = self.graph_store.search_by_fulltext(
-                query_words=tsquery_terms,
-                top_k=top_k * 2,
-                status="activated",
-                scope=scope,
-                search_filter=None,
-                filter=search_filter,
-                user_name=user_name,
-                tsquery_config="jiebaqry",
-            )
+            try:
+                hits = self.graph_store.search_by_fulltext(
+                    query_words=tsquery_terms,
+                    top_k=top_k * 2,
+                    status="activated",
+                    scope=scope,
+                    search_filter=None,
+                    filter=search_filter,
+                    user_name=user_name,
+                    tsquery_config="jiebaqry",
+                )
+            except Exception as e:
+                logger.warning(
+                    f"[PATH-KEYWORD] search_by_fulltext failed, scope={scope}, user_name={user_name}"
+                )
+                hits = []
             for h in hits or []:
                 hid = str(h.get("id") or "").strip().strip("'\"")
                 if not hid: