Properly handle distinct ids that aren't distinct_id

posthog/warehouse/models/join.py

@@ -184,7 +184,7 @@ def _join_function_for_experiments(
                                     ]
                                 ),
                                 op=ast.CompareOperationOp.Eq,
-                                right=ast.Field(chain=[join_to_add.to_table, "distinct_id"]),
+                                right=ast.Field(chain=[join_to_add.to_table, *self.joining_table_key.split(".")]),
                             ),
                             ast.CompareOperation(
                                 left=ast.Field(