MySQL :: MySQL 5.0 Reference Manual :: 9.1.13.7 Asian Character Sets

MySQL 5.0 Reference Manual :: 9 Internationalization and Localization :: 9.1 Character Set Support :: 9.1.13 Character Sets and Collations That MySQL Supports :: 9.1.13.7 Asian Character Sets

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9.1.13.7. Asian Character Sets

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9.1.13.7.1. The cp932 Character Set

The Asian character sets that we support include Chinese, Japanese, Korean, and Thai. These can be complicated. For example, the Chinese sets must allow for thousands of different characters. See Section 9.1.13.7.1, “The cp932 Character Set”, for additional information about the cp932 and sjis character sets.

For answers to some common questions and problems relating support for Asian character sets in MySQL, see Section A.11, “MySQL 5.0 FAQ — MySQL Chinese, Japanese, and Korean Character Sets”.

big5 (Big5 Traditional Chinese) collations:
- big5_bin
- big5_chinese_ci (default)
cp932 (SJIS for Windows Japanese) collations:
- cp932_bin
- cp932_japanese_ci (default)
eucjpms (UJIS for Windows Japanese) collations:
- eucjpms_bin
- eucjpms_japanese_ci (default)
euckr (EUC-KR Korean) collations:
- euckr_bin
- euckr_korean_ci (default)
gb2312 (GB2312 Simplified Chinese) collations:
- gb2312_bin
- gb2312_chinese_ci (default)
gbk (GBK Simplified Chinese) collations:
- gbk_bin
- gbk_chinese_ci (default)
sjis (Shift-JIS Japanese) collations:
- sjis_bin
- sjis_japanese_ci (default)
tis620 (TIS620 Thai) collations:
- tis620_bin
- tis620_thai_ci (default)
ujis (EUC-JP Japanese) collations:
- ujis_bin
- ujis_japanese_ci (default)

The big5_chinese_ci collation sorts on number of strokes.

For additional information about Asian collations in MySQL, see Collation-Charts.Org (big5, cp932, eucjpms, euckr, gb2312, gbk, sjis, tis620, ujis).

9.1.13.7.1. The `cp932` Character Set

Why is cp932 needed?

In MySQL, the sjis character set corresponds to the Shift_JIS character set defined by IANA, which supports JIS X0201 and JIS X0208 characters. (See http://www.iana.org/assignments/character-sets.)

However, the meaning of “SHIFT JIS” as a descriptive term has become very vague and it often includes the extensions to Shift_JIS that are defined by various vendors.

For example, “SHIFT JIS” used in Japanese Windows environments is a Microsoft extension of Shift_JIS and its exact name is Microsoft Windows Codepage : 932 or cp932. In addition to the characters supported by Shift_JIS, cp932 supports extension characters such as NEC special characters, NEC selected — IBM extended characters, and IBM extended characters.

Many Japanese users have experienced problems using these extension characters. These problems stem from the following factors:

MySQL automatically converts character sets.
Character sets are converted via Unicode (ucs2).
The sjis character set does not support the conversion of these extension characters.
There are several conversion rules from so-called “SHIFT JIS” to Unicode, and some characters are converted to Unicode differently depending on the conversion rule. MySQL supports only one of these rules (described later).

The MySQL cp932 character set is designed to solve these problems. It is available as of MySQL 5.0.3.

Because MySQL supports character set conversion, it is important to separate IANA Shift_JIS and cp932 into two different character sets because they provide different conversion rules.

How does cp932 differ from sjis?

The cp932 character set differs from sjis in the following ways:

cp932 supports NEC special characters, NEC selected — IBM extended characters, and IBM selected characters.
Some cp932 characters have two different code points, both of which convert to the same Unicode code point. When converting from Unicode back to cp932, one of the code points must be selected. For this “round trip conversion,” the rule recommended by Microsoft is used. (See http://support.microsoft.com/kb/170559/EN-US/.)

The conversion rule works like this:
- If the character is in both JIS X 0208 and NEC special characters, use the code point of JIS X 0208.
- If the character is in both NEC special characters and IBM selected characters, use the code point of NEC special characters.
- If the character is in both IBM selected characters and NEC selected — IBM extended characters, use the code point of IBM extended characters.
The table shown at http://www.microsoft.com/globaldev/reference/dbcs/932.htm provides information about the Unicode values of cp932 characters. For cp932 table entries with characters under which a four-digit number appears, the number represents the corresponding Unicode (ucs2) encoding. For table entries with an underlined two-digit value appears, there is a range of cp932 character values that begin with those two digits. Clicking such a table entry takes you to a page that displays the Unicode value for each of the cp932 characters that begin with those digits.

The following links are of special interest. They correspond to the encodings for the following sets of characters:
- NEC special characters:
```
http://www.microsoft.com/globaldev/reference/dbcs/932/932_87.htm
```
- NEC selected — IBM extended characters:
```
http://www.microsoft.com/globaldev/reference/dbcs/932/932_ED.htm
http://www.microsoft.com/globaldev/reference/dbcs/932/932_EE.htm
```
- IBM selected characters:
```
http://www.microsoft.com/globaldev/reference/dbcs/932/932_FA.htm
http://www.microsoft.com/globaldev/reference/dbcs/932/932_FB.htm
http://www.microsoft.com/globaldev/reference/dbcs/932/932_FC.htm
```
Starting from version 5.0.3, cp932 supports conversion of user-defined characters in combination with eucjpms, and solves the problems with sjis/ujis conversion. For details, please refer to http://www.opengroup.or.jp/jvc/cde/sjis-euc-e.html.

For some characters, conversion to and from ucs2 is different for sjis and cp932. The following tables illustrate these differences.

Conversion to ucs2:

`sjis`/`cp932` Value	`sjis` -> `ucs2` Conversion	`cp932` -> `ucs2` Conversion
5C	005C	005C
7E	007E	007E
815C	2015	2015
815F	005C	FF3C
8160	301C	FF5E
8161	2016	2225
817C	2212	FF0D
8191	00A2	FFE0
8192	00A3	FFE1
81CA	00AC	FFE2

Conversion from ucs2:

`ucs2` value	`ucs2` -> `sjis` Conversion	`ucs2` -> `cp932` Conversion
005C	815F	5C
007E	7E	7E
00A2	8191	3F
00A3	8192	3F
00AC	81CA	3F
2015	815C	815C
2016	8161	3F
2212	817C	3F
2225	3F	8161
301C	8160	3F
FF0D	3F	817C
FF3C	3F	815F
FF5E	3F	8160
FFE0	3F	8191
FFE1	3F	8192
FFE2	3F	81CA

Users of any Japanese character sets should be aware that using --character-set-client-handshake (or --skip-character-set-client-handshake) has an important effect. See Section 5.1.2, “Server Command Options”.

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User Comments

Posted by [name withheld] on September 27 2005 7:25am

[Delete] [Edit]

As of MySQL 4.1.14,
Please notice that for Traditional Chinese (BIG5), collation 'big5_chinese_ci' uses stroke count of the characters on ordering; while in Simplified Chinese (GB2312), collation 'gb2312_chinese_ci' uses Pinyin of the characters on ordering.

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9.1.13.7. Asian Character Sets

9.1.13.7.1. The cp932 Character Set

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9.1.13.7.1. The `cp932` Character Set