SQL 从 PostgreSQL 中的数字获取月份名称
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Get month name from number in PostgreSQL
提问by user007
I have a table with a column month(integer). In this column I store values like 1, 2, .. 12.
But I have to show the month name.
我有一个带有列month( integer)的表。在这一列中，我存储了诸如1, 2, .. 12.
但我必须显示月份名称。
Ex:
If the value is 1I need to display jan.
例如：如果值是1我需要显示jan.
回答by Erwin Brandstetter
Basically what @small_duck already posted, but a couple of improvements:
基本上@small_duck 已经发布了，但有一些改进：
SELECT to_char(to_timestamp (4::text, 'MM'), 'TMmon')
A plain cast to text
4::textis enough, no need forto_char(..).Question asks for lower case "jan", there is a template patternfor that:
mon.If you want to localize the output, prefix the template with the modifier
TM.
回答by small_duck
There might be a quicker answer, but it seems to be possible by:
可能有一个更快的答案，但似乎可以通过：
- Turning your int into a string
- Reading that string as a timestamp
- Displaying the month of the timestamp.
- 把你的 int 变成一个字符串
- 将该字符串作为时间戳读取
- 显示时间戳的月份。
For example:
例如：
select to_char(to_timestamp(to_char(4, '999'), 'MM'), 'Mon')
returns 'Apr'.
返回“四月”。
You can turn it into a function:
你可以把它变成一个函数：
create function to_month(integer) returns varchar as
$$
select to_char(to_timestamp(to_char(, '999'), 'MM'), 'Mon');
$$ language sql
and use it throughout your code.
并在整个代码中使用它。
select to_month(month_column) from mytable
