postgreSQL中文排序的问题

安装时locale选择“chinese, singapore”，表的字符集选择“utf8”.
对中文排序时，果然像网上说的一样，排的乱七八糟。SQL和排序结果如下：

select '五指山' as a union select '三叉口' as a union
select '一线天' as a union select '二人转' as a union
select '四喜丸子' as a union select '六扇门' as a union
select '中文' as a union select '阿里山' as a union
select '宝贝' as a union select '茶叶' as a
order by a

"一线天"
"三叉口"
"中文"
"二人转"
"五指山"
"六扇门"
"四喜丸子"
"宝贝"
"茶叶"
"阿里山"

查到一个据说可以解决此问题的方法，生成如下函数。但学生执行这段SQL是报错。。

  create or replace function text2bytea(text) returns bytea as
  $$
  return $1;
  $$ language plpgsql immutable;

报错内容：
ERROR: syntax error at or near "return"
LINE 3: return $1;
  ^

********** 错误 **********

ERROR: syntax error at or near "return"
SQL 状态: 42601
字符:74