Warn / raise for returning() / return_defaults() combinations

A warning is emmitted if a returning() method such as
:meth:`_sql.Insert.returning` is called multiple times, as this does not
yet support additive operation.  Version 1.4 will support additive
operation for this.  Additionally, any combination of the
:meth:`_sql.Insert.returning` and :meth:`_sql.Insert.return_defaults`
methods now raises an error as these methods are mutually exclusive;
previously the operation would fail silently.

Fixes: #5691
Change-Id: Id95e0f9da48bba0b59439cb26564f0daa684c8e3

1 files changed, 1 insertions, 1 deletions

diff --git a/doc/build/tutorial/data.rst b/doc/build/tutorial/data.rst
index 27a21b097..849b706cc 100644
--- a/doc/build/tutorial/data.rst
+++ b/doc/build/tutorial/data.rst
@@ -1502,7 +1502,7 @@ be iterated::
     ...     delete(user_table).where(user_table.c.name == 'patrick').
     ...     returning(user_table.c.id, user_table.c.name)
     ... )
-    >>> print(delete_stmt.returning(user_table.c.id, user_table.c.name))
+    >>> print(delete_stmt)
     {opensql}DELETE FROM user_account
     WHERE user_account.name = :name_1
     RETURNING user_account.id, user_account.name