feat(api): allow selectors in order_by

ibis/expr/types/relations.py

@@ -1296,7 +1296,13 @@ def head(self, n: int = 5) -> Table:
 
     def order_by(
         self,
-        by: str | ir.Column | Sequence[str] | Sequence[ir.Column] | None,
+        by: str
+        | ir.Column
+        | s.Selector
+        | Sequence[str]
+        | Sequence[ir.Column]
+        | Sequence[s.Selector]
+        | None,
     ) -> Table:
         """Sort a table by one or more expressions.
 
@@ -1421,19 +1427,21 @@ def order_by(
         │     2 │ B      │     6 │
         └───────┴────────┴───────┘
         """
+        import ibis.selectors as s
+
         sort_keys = []
         for item in util.promote_list(by):
             if isinstance(item, tuple):
                 if len(item) != 2:
-                    raise ValueError(
-                        "Tuple must be of length 2, got {}".format(len(item))
-                    )
-                item = (bind_expr(self, item[0]), item[1])
-                used_tuple_syntax = True
+                    raise ValueError(f"Tuple must be of length 2, got {len(item):d}")
+                sort_keys.append(bind_expr(self, item[0]), item[1])
+            elif isinstance(item, s.Selector):
+                sort_keys.extend(item.expand(self))
             else:
-                item = bind_expr(self, item)
-            sort_keys.append(item)
+                sort_keys.append(bind_expr(self, item))
 
+        if not sort_keys:
+            raise com.IbisError("At least one sort key must be provided")
         return self.op().order_by(sort_keys).to_expr()
 
     def union(self, table: Table, *rest: Table, distinct: bool = False) -> Table:

ibis/tests/expr/test_selectors.py

@@ -475,3 +475,18 @@ def test_c_error_on_misspelled_column(penguins):
     sel = s.any_of(s.c("island", "inland"))
     with pytest.raises(exc.IbisInputError, match=match):
         penguins.select(sel)
+
+
+def test_order_by_with_selectors(penguins):
+    expr = penguins.order_by(s.of_type("string"))
+    assert tuple(key.name for key in expr.op().sort_keys) == (
+        "species",
+        "island",
+        "sex",
+    )
+
+    expr = penguins.order_by(s.all())
+    assert tuple(key.name for key in expr.op().sort_keys) == tuple(expr.columns)
+
+    with pytest.raises(exc.IbisError):
+        penguins.order_by(~s.all())