Method go

lib/sqlalchemy/testing/fixtures/sql.py:523–536

(query, *expr)

        from sqlalchemy.dialects.postgresql import distinct_on

        def go(query, *expr):
            if request.param == "legacy":
                if expr:
                    with expect_deprecated(
                        "Passing expression to ``distinct`` to generate a "
                        "DISTINCT "
                        "ON clause is deprecated. Use instead the "
                        "``postgresql.distinct_on`` function as an extension."
                    ):
                        return query.distinct(*expr)
                else:
                    return query.distinct()
            elif request.param == "new":
                return query.ext(distinct_on(*expr))

        return go