按Postgres的hstore属性排序无法正常工作

时间:2018-07-29 12:09:08

标签: sql postgresql hstore

我使用Postgres 10.4,在一个简单的查询中出现了奇怪的排序行为。

我的表是这样定义的:

CREATE TABLE country (
    id           varchar(2)   NOT NULL PRIMARY KEY,
    order_by     smallint,
    app_locale   boolean      DEFAULT false NOT NULL,
    country      boolean      DEFAULT false NOT NULL,
    lang         boolean      DEFAULT false NOT NULL,
    nationality  boolean      DEFAULT false NOT NULL,
    c_name       hstore,
    l_name       hstore,
    n_name       hstore,
    active       boolean      DEFAULT false NOT NULL,
    language     varchar(6)
);

此简单查询应返回按英语国籍名称排序的国家/地区:

select id, c_name
from country c
where active = true
and   c.nationality = true
and   id in ('de','fr','be','lu','kz','af','ad') -- limit the result a bit
order by c.n_name -> 'en'

意外的结果是:

id  c_name
be  "de"=>"Belgien", "lb"=>"Belsch", "en"=>"Belgium", "fr"=>"Belgique"
fr  "de"=>"Frankreich", "lb"=>"Frankräich", "en"=>"France", "fr"=>"France"
de  "de"=>"Deutschland", "lb"=>"Däitschland", "en"=>"Germany", "fr"=>"Allemagne"
lu  "de"=>"Luxemburg", "lb"=>"Lëtzebuerg", "en"=>"Luxembourg", "fr"=>"Luxembourg"
ad  "en"=>"Andorra"
kz  "en"=>"Kazakhstan"
af  "de"=>"Afghanistan", "en"=>"Afghanistan", "fr"=>"Afghanistan"

这是什么问题?

1 个答案:

答案 0 :(得分:4)

您在order by中使用了错误的列:

select id, c_name
from country c
where active = true
and c.nationality = true
and id in ('de','fr','be','lu','kz','af','ad')
order by c_name -> 'en'