Method compile

django/db/models/expressions.py:816–825

(self, side, compiler, connection)

class DurationExpression(CombinedExpression):
    def compile(self, side, compiler, connection):
        try:
            output = side.output_field
        except FieldError:
            pass
        else:
            if output.get_internal_type() == "DurationField":
                sql, params = compiler.compile(side)
                return connection.ops.format_for_duration_arithmetic(sql), params
        return compiler.compile(side)

    def as_sql(self, compiler, connection):
        if connection.features.has_native_duration_field: