fix: deduplicate relationship joins when searchable_fields and facet_fields reference the same model (#217)

src/fastapi_toolsets/crud/factory.py

@@ -116,8 +116,12 @@ def _apply_joins(q: Any, joins: JoinType | None, outer_join: bool) -> Any:
 
 def _apply_search_joins(q: Any, search_joins: list[Any]) -> Any:
     """Apply relationship-based outer joins (from search/filter_by) to a query."""
+    seen: set[str] = set()
     for join_rel in search_joins:
-        q = q.outerjoin(join_rel)
+        key = str(join_rel)
+        if key not in seen:
+            seen.add(key)
+            q = q.outerjoin(join_rel)
     return q
 
 

src/fastapi_toolsets/crud/search.py

@@ -242,13 +242,19 @@ async def build_facets(
         else:
             q = select(column).select_from(model).distinct()
 
-        # Apply base joins (already done on main query, but needed here independently)
+        # Apply base joins (deduplicated) — needed here independently
+        seen_joins: set[str] = set()
         for rel in base_joins or []:
-            q = q.outerjoin(rel)
+            rel_key = str(rel)
+            if rel_key not in seen_joins:
+                seen_joins.add(rel_key)
+                q = q.outerjoin(rel)
 
-        # Add any extra joins required by this facet field that aren't already in base_joins
+        # Add any extra joins required by this facet field that aren't already applied
         for rel in rels:
-            if str(rel) not in existing_join_keys:
+            rel_key = str(rel)
+            if rel_key not in existing_join_keys and rel_key not in seen_joins:
+                seen_joins.add(rel_key)
                 q = q.outerjoin(rel)
 
         if base_filters: