PostgreSQL - 从函数返回 n 大小的 varchar [英] PostgreSQL - return n-sized varchar from function
问题描述
正如我在文档中发现的那样:
<块引用>带括号的类型修饰符(例如,类型的精度字段数字)被 CREATE FUNCTION 丢弃
是否有其他方法可以从 plpgsql 函数返回 varchar(N) 类型?
<小时>问题更新:
在图片上你可以看到 Name 列被识别为 varchar(128),而 Number 列被识别为非大小的 varchar
f_concat 函数返回:cast(res as varchar(255));
您可以通过创建一个
As I found in documentation:
Parenthesized type modifiers (e.g., the precision field for type numeric) are discarded by CREATE FUNCTION
Are there any alternatives to return varchar(N) type from plpgsql function?
question update:
On picture you can see that Name column recognised as varchar(128), however Number column is recognised as nonsized varchar
f_concat function returns: cast(res as varchar(255));
You can preserve the type modifier for a function result by creating a domain. Postgres will use the underlying varchar(N)
type when sending column descriptions to your client:
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