Add as_prepended kwarg to ModelBase.field_names_sql

Author: bdowning

sql_athame/dataclasses.py

@@ -230,8 +230,21 @@ def field_names(cls, *, exclude: FieldNamesSet = ()) -> list[str]:
 
     @classmethod
     def field_names_sql(
-        cls, *, prefix: Optional[str] = None, exclude: FieldNamesSet = ()
+        cls,
+        *,
+        prefix: Optional[str] = None,
+        exclude: FieldNamesSet = (),
+        as_prepended: str | None = None,
     ) -> list[Fragment]:
+        if as_prepended:
+            return [
+                sql(
+                    "{} AS {}",
+                    sql.identifier(f, prefix=prefix),
+                    sql.identifier(f"{as_prepended}{f}"),
+                )
+                for f in cls.field_names(exclude=exclude)
+            ]
         return [
             sql.identifier(f, prefix=prefix) for f in cls.field_names(exclude=exclude)
         ]

tests/test_dataclasses.py

@@ -71,6 +71,14 @@ class Test(ModelBase, table_name="table"):
         sql(",").join(t.field_values_sql()),
     ).query() == ('INSERT INTO table ("foo","bar") VALUES ($1,$2)', [42, "hi"])
 
+    assert list(
+        sql(
+            "SELECT {fields} FROM {tbl}",
+            fields=sql.list(Test.field_names_sql(as_prepended="p_")),
+            tbl=Test.table_name_sql(),
+        )
+    ) == ['SELECT "foo" AS "p_foo", "bar" AS "p_bar" FROM "table"']
+
 
 def test_modelclass_implicit_types():
     @dataclass