Fixed support for VectorStore search filters with multiple $like/$ilike/$in/$nin on same column (langchain-ai#217)

Fixed issue langchain-ai#216. 

Pull request adds a filter test case that was failing and the fix for
internal function _handle_field_filter.
The function fix is to add an unique identifier to the column names of
operator in, nin, like and ilike

---------

Co-authored-by: AD101\z004nm6m <[email protected]>

Author: 2 people

langchain_postgres/v2/async_vectorstore.py

@@ -1095,46 +1095,48 @@ def _handle_field_filter(
             operator = "$eq"
             filter_value = value
 
+        suffix_id = str(uuid.uuid4()).split("-")[0]
         if operator in COMPARISONS_TO_NATIVE:
             # Then we implement an equality filter
             # native is trusted input
             native = COMPARISONS_TO_NATIVE[operator]
-            id = str(uuid.uuid4()).split("-")[0]
-            return f"{field} {native} :{field}_{id}", {f"{field}_{id}": filter_value}
+            param_name = f"{field}_{suffix_id}"
+            return f"{field} {native} :{param_name}", {f"{param_name}": filter_value}
         elif operator == "$between":
             # Use AND with two comparisons
             low, high = filter_value
-
-            return f"({field} BETWEEN :{field}_low AND :{field}_high)", {
-                f"{field}_low": low,
-                f"{field}_high": high,
+            low_param_name = f"{field}_low_{suffix_id}"
+            high_param_name = f"{field}_high_{suffix_id}"
+            return f"({field} BETWEEN :{low_param_name} AND :{high_param_name})", {
+                f"{low_param_name}": low,
+                f"{high_param_name}": high,
             }
-        elif operator in {"$in", "$nin", "$like", "$ilike"}:
+        elif operator in {"$in", "$nin"}:
             # We'll do force coercion to text
-            if operator in {"$in", "$nin"}:
-                for val in filter_value:
-                    if not isinstance(val, (str, int, float)):
-                        raise NotImplementedError(
-                            f"Unsupported type: {type(val)} for value: {val}"
-                        )
-
-                    if isinstance(val, bool):  # b/c bool is an instance of int
-                        raise NotImplementedError(
-                            f"Unsupported type: {type(val)} for value: {val}"
-                        )
-
-            if operator in {"$in"}:
-                return f"{field} = ANY(:{field}_in)", {f"{field}_in": filter_value}
-            elif operator in {"$nin"}:
-                return f"{field} <> ALL (:{field}_nin)", {f"{field}_nin": filter_value}
-            elif operator in {"$like"}:
-                return f"({field} LIKE :{field}_like)", {f"{field}_like": filter_value}
-            elif operator in {"$ilike"}:
-                return f"({field} ILIKE :{field}_ilike)", {
-                    f"{field}_ilike": filter_value
+            for val in filter_value:
+                if not isinstance(val, (str, int, float)):
+                    raise NotImplementedError(
+                        f"Unsupported type: {type(val)} for value: {val}"
+                    )
+
+                if isinstance(val, bool):  # b/c bool is an instance of int
+                    raise NotImplementedError(
+                        f"Unsupported type: {type(val)} for value: {val}"
+                    )
+            param_name = f"{field}_{operator.replace('$', '')}_{suffix_id}"
+            if operator == "$in":
+                return f"{field} = ANY(:{param_name})", {f"{param_name}": filter_value}
+            else:  # i.e. $nin
+                return f"{field} <> ALL (:{param_name})", {
+                    f"{param_name}": filter_value
                 }
-            else:
-                raise NotImplementedError()
+
+        elif operator in {"$like", "$ilike"}:
+            param_name = f"{field}_{operator.replace('$', '')}_{suffix_id}"
+            if operator == "$like":
+                return f"({field} LIKE :{param_name})", {f"{param_name}": filter_value}
+            else:  # i.e. $ilike
+                return f"({field} ILIKE :{param_name})", {f"{param_name}": filter_value}
         elif operator == "$exists":
             if not isinstance(filter_value, bool):
                 raise ValueError(

tests/unit_tests/fixtures/metadata_filtering_data.py

@@ -210,7 +210,7 @@
         {"name": {"$nin": ["Smart Fitness Tracker", "Stainless Steel Water Bottle"]}},
         ["WH001", "EC002"],
     ),
-    ## with numeric fields
+    # with numeric fields
     (
         {"available_quantity": {"$nin": [50, 0, 10]}},
         ["FT004"],
@@ -225,6 +225,11 @@
         {"name": {"$like": "%less%"}},  # adam and jane
         ["WH001", "WB003"],
     ),
+    # Test combination of $like and $and
+    (
+        {"$or": [{"code": {"$like": "WH00%"}}, {"code": {"$like": "EC00%"}}]},
+        ["WH001", "EC002"],
+    ),
     # These involve the special operator $exists
     (
         {"tags": {"$exists": False}},