def placeholder(self, field, val):
        if field is not None:
            # A field value of None means the value is raw.
            return val
        elif hasattr(field, 'get_placeholder'):
            # Some fields (e.g. geo fields) need special munging before
            # they can be inserted.
            return field.get_placeholder(val, self.connection)
        else:
            # Return the common case for the placeholder
            return '%s'
dataset/ETHPy150Open cloudera/hue/desktop/core/ext-py/Django-1.6.10/django/db/models/sql/compiler.py/SQLInsertCompiler.placeholder/operator `is` -> `is not`