fix: [2.5]Support hybrid search with expression template (#2489)

issue: milvus-io/milvus#38616

Signed-off-by: Cai Zhang <[email protected]>

examples/hybrid_search.py

@@ -68,7 +68,27 @@
     req = AnnSearchRequest(**search_param)
     req_list.append(req)
 
-print("rank by RRFRanker")
+print(fmt.format("rank by RRFRanker"))
+hybrid_res = milvus_client.hybrid_search(collection_name, req_list, RRFRanker(), default_limit, output_fields=["random"])
+for hits in hybrid_res:
+    for hit in hits:
+        print(f" hybrid search hit: {hit}")
+
+req_list = []
+for i in range(len(field_names)):
+    # 4. generate search data
+    vectors_to_search = rng.random((nq, dim))
+    search_param = {
+        "data": vectors_to_search,
+        "anns_field": field_names[i],
+        "param": {"metric_type": "L2"},
+        "limit": default_limit,
+        "expr": "random > {radius}",
+        "expr_params": {"radius": 0.5}}
+    req = AnnSearchRequest(**search_param)
+    req_list.append(req)
+
+print(fmt.format("rank by RRFRanker with expression template"))
 hybrid_res = milvus_client.hybrid_search(collection_name, req_list, RRFRanker(), default_limit, output_fields=["random"])
 for hits in hybrid_res:
     for hit in hits:

examples/hybrid_search/hybrid_search.py

@@ -79,14 +79,39 @@
     req = AnnSearchRequest(**search_param)
     req_list.append(req)
 
+print(fmt.format("rank by WightedRanker"))
 hybrid_res = hello_milvus.hybrid_search(req_list, WeightedRanker(*weights), default_limit, output_fields=["random"])
+for hits in hybrid_res:
+    for hit in hits:
+        print(f" hybrid search hit: {hit}")
 
-print("rank by WightedRanker")
+print(fmt.format("rank by RRFRanker"))
+hybrid_res = hello_milvus.hybrid_search(req_list, RRFRanker(), default_limit, output_fields=["random"])
+for hits in hybrid_res:
+    for hit in hits:
+        print(f" hybrid search hit: {hit}")
+
+req_list = []
+for i in range(len(field_names)):
+    # 4. generate search data
+    vectors_to_search = rng.random((nq, dim))
+    search_param = {
+        "data": vectors_to_search,
+        "anns_field": field_names[i],
+        "param": {"metric_type": "L2"},
+        "limit": default_limit,
+        "expr": "random > {radius}",
+        "expr_params": {"radius": 0.5}}
+    req = AnnSearchRequest(**search_param)
+    req_list.append(req)
+
+print(fmt.format("rank by WightedRanker with expression template"))
+hybrid_res = hello_milvus.hybrid_search(req_list, WeightedRanker(*weights), default_limit, output_fields=["random"])
 for hits in hybrid_res:
     for hit in hits:
         print(f" hybrid search hit: {hit}")
 
-print("rank by RRFRanker")
+print(fmt.format("rank by RRFRanker with expression template"))
 hybrid_res = hello_milvus.hybrid_search(req_list, RRFRanker(), default_limit, output_fields=["random"])
 for hits in hybrid_res:
     for hit in hits:

pymilvus/client/abstract.py

@@ -417,6 +417,7 @@ def __init__(
         param: Dict,
         limit: int,
         expr: Optional[str] = None,
+        expr_params: Optional[dict] = None,
     ):
         self._data = data
         self._anns_field = anns_field
@@ -426,6 +427,7 @@ def __init__(
         if expr is not None and not isinstance(expr, str):
             raise DataTypeNotMatchException(message=ExceptionsMessage.ExprType % type(expr))
         self._expr = expr
+        self._expr_params = expr_params
 
     @property
     def data(self):
@@ -447,6 +449,10 @@ def limit(self):
     def expr(self):
         return self._expr
 
+    @property
+    def expr_params(self):
+        return self._expr_params
+
     def __str__(self):
         return {
             "anns_field": self.anns_field,

pymilvus/client/grpc_handler.py

@@ -868,6 +868,7 @@ def hybrid_search(
                 req.expr,
                 partition_names=partition_names,
                 round_decimal=round_decimal,
+                expr_params=req.expr_params,
                 **kwargs,
             )
             requests.append(search_request)

pymilvus/client/prepare.py

@@ -997,7 +997,9 @@ def search_requests_with_expr(
             placeholder_group=plg_str,
             dsl_type=common_types.DslType.BoolExprV1,
             search_params=req_params,
-            expr_template_values=cls.prepare_expression_template(kwargs.get("expr_params", {})),
+            expr_template_values=cls.prepare_expression_template(
+                {} if kwargs.get("expr_params") is None else kwargs.get("expr_params")
+            ),
         )
         if expr is not None:
             request.dsl = expr

pymilvus/milvus_client/async_milvus_client.py

@@ -286,7 +286,6 @@ async def hybrid_search(
         partition_names: Optional[List[str]] = None,
         **kwargs,
     ) -> List[List[dict]]:
-
         conn = self._get_connection()
         try:
             res = await conn.hybrid_search(