Oracle中的NLS_CHARACTERSET WE8ISO8859P1和UTF8问题 [英] NLS_CHARACTERSET WE8ISO8859P1 and UTF8 issues in Oracle

问题描述

我目前在oracle中使用了一个具有NLS_CHARACTERSET WE8ISO8859P1的数据库，所以我想在varchar2字段中存储一个值为maž（重音字符），因此在数据库中它存储为maå¾。现在，当我尝试使用查询select * from table from fieldValue ='maž'检索它时，它返回0行，然后当我尝试再次插入它时，它给出了一个约束错误，表示值已经存在。

I am currently using a Database in oracle which has NLS_CHARACTERSET WE8ISO8859P1 so lets say I store a value in varchar2 field which is maž (accented character) so in database it gets stored as maå¾ . Now when I try to retrieve it with query select * from table where fieldValue = 'maž' it returns 0 rows, and then when i try to insert it again it gives me a constraint error saying value already exist.

如何克服这种情况。
我通过Java代码执行此操作

How to overcome such situation. I am doing this via Java code

推荐答案

http://docs.oracle.com/cd/B19306_01/server.102/b14225/ch2charset.htm#g1009784

Oracle字符集名称：WE8ISO8859P1

描述：西欧8位ISO 8859第1部分

地区：WE（西欧）

用于表示角色的位数：8

另一方面，UTF-8使用几个字节来存储符号。

On the other hand, UTF-8 uses several bytes to store a symbol.

如果您的数据库使用WE8ISO8859P1且列类型为来自VARCHAR组（不是NVARCHAR）并且您正在插入代码> 255的符号，此符号将转换为WE8ISO8859P1并且某些信息将丢失。

If your database uses WE8ISO8859P1 and the column type is from VARCHAR group (not NVARCHAR) and you're inserting a symbol which code > 255, this symbol will be transformed to WE8ISO8859P1 and some information will be lost.

要放简单地说，如果你将UTF-8插入到具有单字节字符集的数据库中，你的数据就会丢失。

To put it simply, if you're inserting UTF-8 into a db with single-byte character set, your data is lost.

上面的链接描述了如何解决此问题的不同方案。

The link above describes different scenarios how to tackle this issue.

您还可以尝试Oracle asciistr / unistr 函数，但一般来说它不是处理此类问题的好方法。

You can also try Oracle asciistr/unistr functions, but in general it's not a good way to deal with such problems.

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