def as_subquery_condition(self, alias, columns, qn):
        qn2 = self.connection.ops.quote_name
        if len(columns) > 1:
            sql, params = self.as_sql()
            return '%s.%s IN (%s)' % (qn(alias), qn2(columns[0]), sql), params

        for index, select_col in enumerate(self.query.select):
            lhs = '%s.%s' % (qn(select_col.col[0]), qn2(select_col.col[1]))
            rhs = '%s.%s' % (qn(alias), qn2(columns[index]))
            self.query.where.add(
                QueryWrapper('%s = %s' % (lhs, rhs), []), 'AND')

        sql, params = self.as_sql()
        return 'EXISTS (%s)' % sql, params
dataset/ETHPy150Open cloudera/hue/desktop/core/ext-py/Django-1.6.10/django/db/models/sql/compiler.py/SQLCompiler.as_subquery_condition/operator `==` -> `>`