DB2 UTF-8编码:Umlaut转换为CHAR(1)? [英] DB2 UTF-8 encoding: Umlaut to CHAR(1)?

问题描述

UTF-8编码的DB2数据库中的"CHAR(1)"是什么意思?

What does "CHAR(1)" in a UTF-8 encoded DB2 database mean?

我可以在CHAR(1)的列中插入一个特殊字符(例如，在UTF-8中使用2个八位位组的字符)吗?

Can I insert a special character (e.g. one that takes 2 octets in UTF-8) into a column of CHAR(1)?

还是UTF-8中的CHAR(1)总是意味着它具有一个字节/八位位组的容量，即，将Umlaut插入其中会失败吗?

Or does CHAR(1) in UTF-8 always mean, that it has capacity for one byte / octet, i.e. such that inserting an Umlaut into it will fail ?

我阅读了这篇有趣的 developerWorks 文章，但这对我的简单问题来说很深...

I read through this interesting developerWorks article, but it's going to deep for my simple question...

推荐答案

这要视情况而定. :)

It depends. :)

DB2引入了code units来帮助设计基于字符数而不是字节数的字符串类型的列. CREATE TABLE 语句概述了数据类型，并解释了CHAR和VARCHAR.如果使用字符数，则DB2假定最坏的情况-每个字符4个字节/八位字节-用于长度计算.

DB2 introduced code units to help with designing string-typed columns that are based on number of characters and not number of bytes. The CREATE TABLE statement has an overview of data types and also explains CHAR and VARCHAR. If number of characters is used, DB2 is assuming the worst case - 4 bytes/octets per character - for length computations.

数据库配置 string_units 确定默认情况下是否考虑字符数(CODEUNITS32)或字节数(SYSTEM).

The database configuration string_units determines whether by default the number of characters (CODEUNITS32) or the number of bytes (SYSTEM) is considered.

回到您的问题:如果您未指定任何内容，则将需要2个八位位组的特殊字符插入CHAR(1)可能会失败.如果指定了CODEUNITS32，则它将成功.

Coming back to your question: If you did not specify anything, inserting a special character that needs 2 octets into a CHAR(1) will likely fail. If CODEUNITS32 was specified, then it will succeed.

这篇关于DB2 UTF-8编码:Umlaut转换为CHAR(1)?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！