Added method to generate unique variable names for specific pathes.

Author: tonioo

neomodel/async_/match.py

@@ -503,9 +503,11 @@ def create_relation_identifier(self) -> str:
         self._relation_identifier_count += 1
         return f"r{self._relation_identifier_count}"
 
-    def create_node_identifier(self, prefix: str) -> str:
-        self._node_identifier_count += 1
-        return f"{prefix}{self._node_identifier_count}"
+    def create_node_identifier(self, prefix: str, path: str) -> str:
+        if path not in self.node_set._unique_variables:
+            self._node_identifier_count += 1
+            return f"{prefix}{self._node_identifier_count}"
+        return prefix
 
     def build_order_by(self, ident: str, source: "AsyncNodeSet") -> None:
         if "?" in source.order_by_elements:
@@ -619,7 +621,7 @@ def build_traversal_from_path(
                     rhs_name = relation["alias"]
                 else:
                     rhs_name = f"{rhs_label.lower()}_{rel_iterator}"
-                    rhs_name = self.create_node_identifier(rhs_name)
+                    rhs_name = self.create_node_identifier(rhs_name, rel_iterator)
             rhs_ident = f"{rhs_name}:{rhs_label}"
             if relation["include_in_return"] and not already_present:
                 self._additional_return(rhs_name)
@@ -1381,6 +1383,7 @@ def __init__(self, source: Any) -> None:
         self._extra_results: list = []
         self._subqueries: list[Subquery] = []
         self._intermediate_transforms: list = []
+        self._unique_variables: list[str] = []
 
     def __await__(self) -> Any:
         return self.all().__await__()  # type: ignore[attr-defined]
@@ -1552,6 +1555,11 @@ def _register_relation_to_fetch(
             item["alias"] = alias
         return item
 
+    def unique_variables(self, *pathes: tuple[str, ...]) -> "AsyncNodeSet":
+        """Generate unique variable names for the given pathes."""
+        self._unique_variables = pathes
+        return self
+
     def fetch_relations(self, *relation_names: tuple[str, ...]) -> "AsyncNodeSet":
         """Specify a set of relations to traverse and return."""
         relations = []

neomodel/sync_/match.py

@@ -501,9 +501,11 @@ def create_relation_identifier(self) -> str:
         self._relation_identifier_count += 1
         return f"r{self._relation_identifier_count}"
 
-    def create_node_identifier(self, prefix: str) -> str:
-        self._node_identifier_count += 1
-        return f"{prefix}{self._node_identifier_count}"
+    def create_node_identifier(self, prefix: str, path: str) -> str:
+        if path not in self.node_set._unique_variables:
+            self._node_identifier_count += 1
+            return f"{prefix}{self._node_identifier_count}"
+        return prefix
 
     def build_order_by(self, ident: str, source: "NodeSet") -> None:
         if "?" in source.order_by_elements:
@@ -617,7 +619,7 @@ def build_traversal_from_path(
                     rhs_name = relation["alias"]
                 else:
                     rhs_name = f"{rhs_label.lower()}_{rel_iterator}"
-                    rhs_name = self.create_node_identifier(rhs_name)
+                    rhs_name = self.create_node_identifier(rhs_name, rel_iterator)
             rhs_ident = f"{rhs_name}:{rhs_label}"
             if relation["include_in_return"] and not already_present:
                 self._additional_return(rhs_name)
@@ -1377,6 +1379,7 @@ def __init__(self, source: Any) -> None:
         self._extra_results: list = []
         self._subqueries: list[Subquery] = []
         self._intermediate_transforms: list = []
+        self._unique_variables: list[str] = []
 
     def __await__(self) -> Any:
         return self.all().__await__()  # type: ignore[attr-defined]
@@ -1548,6 +1551,11 @@ def _register_relation_to_fetch(
             item["alias"] = alias
         return item
 
+    def unique_variables(self, *pathes: tuple[str, ...]) -> "NodeSet":
+        """Generate unique variable names for the given pathes."""
+        self._unique_variables = pathes
+        return self
+
     def fetch_relations(self, *relation_names: tuple[str, ...]) -> "NodeSet":
         """Specify a set of relations to traverse and return."""
         relations = []

test/async_/test_match_api.py

@@ -1155,6 +1155,37 @@ async def test_in_filter_with_array_property():
     ), "Species found by tags with not match tags given"
 
 
+@mark_async_test
+async def test_unique_variables():
+    arabica = await Species(name="Arabica").save()
+    nescafe = await Coffee(name="Nescafe", price=99).save()
+    supplier1 = await Supplier(name="Supplier 1", delivery_cost=3).save()
+    supplier2 = await Supplier(name="Supplier 2", delivery_cost=20).save()
+
+    await nescafe.suppliers.connect(supplier1, {"since": datetime(2020, 4, 1, 0, 0)})
+    await nescafe.suppliers.connect(supplier2, {"since": datetime(2010, 4, 1, 0, 0)})
+    await nescafe.species.connect(arabica)
+
+    nodeset = Supplier.nodes.fetch_relations("coffees", "coffees__species").filter(
+        coffees__name="Nescafe"
+    )
+    ast = await nodeset.query_cls(nodeset).build_ast()
+    query = ast.build_query()
+    assert "coffee_coffees1" in query
+    assert "coffee_coffees2" in query
+
+    nodeset = (
+        Supplier.nodes.fetch_relations("coffees", "coffees__species")
+        .filter(coffees__name="Nescafe")
+        .unique_variables("coffees")
+    )
+    ast = await nodeset.query_cls(nodeset).build_ast()
+    query = ast.build_query()
+    assert "coffee_coffees" in query
+    assert "coffee_coffees1" not in query
+    assert "coffee_coffees2" not in query
+
+
 @mark_async_test
 async def test_async_iterator():
     n = 10

test/sync_/test_match_api.py

@@ -1139,6 +1139,37 @@ def test_in_filter_with_array_property():
     ), "Species found by tags with not match tags given"
 
 
+@mark_sync_test
+def test_unique_variables():
+    arabica = Species(name="Arabica").save()
+    nescafe = Coffee(name="Nescafe", price=99).save()
+    supplier1 = Supplier(name="Supplier 1", delivery_cost=3).save()
+    supplier2 = Supplier(name="Supplier 2", delivery_cost=20).save()
+
+    nescafe.suppliers.connect(supplier1, {"since": datetime(2020, 4, 1, 0, 0)})
+    nescafe.suppliers.connect(supplier2, {"since": datetime(2010, 4, 1, 0, 0)})
+    nescafe.species.connect(arabica)
+
+    nodeset = Supplier.nodes.fetch_relations("coffees", "coffees__species").filter(
+        coffees__name="Nescafe"
+    )
+    ast = nodeset.query_cls(nodeset).build_ast()
+    query = ast.build_query()
+    assert "coffee_coffees1" in query
+    assert "coffee_coffees2" in query
+
+    nodeset = (
+        Supplier.nodes.fetch_relations("coffees", "coffees__species")
+        .filter(coffees__name="Nescafe")
+        .unique_variables("coffees")
+    )
+    ast = nodeset.query_cls(nodeset).build_ast()
+    query = ast.build_query()
+    assert "coffee_coffees" in query
+    assert "coffee_coffees1" not in query
+    assert "coffee_coffees2" not in query
+
+
 @mark_sync_test
 def test_async_iterator():
     n = 10