Oracle 5.0 Reference Manual page 2916

MySQL 5.0 FAQ: MySQL Chinese, Japanese, and Korean Character Sets
NOT SIGN
FULLWIDTH NOT SIGN
This means that MySQL converts the
code point 3F.
cp932
cannot be performed.
B.11.5: What should I do if I want to convert SJIS
Our answer is: "?". There are serious complaints about this: many people would prefer a "loose"
conversion, so that
81CA (NOT SIGN)
We are considering a change to this behavior.
B.11.6: How does MySQL represent the Yen (¥) sign?
A problem arises because some versions of Japanese character sets (both
a reverse solidus (\—also known as a backslash), and others treat it as a yen sign (¥).
MySQL follows only one version of the JIS (Japanese Industrial Standards) standard description. In
MySQL, is always the reverse solidus (\).
5C
B.11.7: Does MySQL plan to make a separate character set where
one other major DBMS does?
This is one possible solution to the Yen sign issue; however, this will not happen in MySQL 5.1 or 6.0.
B.11.8: Of what issues should I be aware when working with Korean character sets in MySQL?
In theory, while there have been several versions of the
set, only one problem has been noted.
We use the "ASCII" variant of EUC-KR, in which the code point
\, instead of the "KS-Roman" variant of EUC-KR, in which the code point
means that you cannot convert Unicode
mysql> SELECT
-> CONVERT('₩' USING euckr) AS euckr,
-> HEX(CONVERT('₩' USING euckr)) AS hexeuckr;
+-------+----------+
| euckr | hexeuckr |
+-------+----------+
| ? | 3F |
+-------+----------+
1 row in set (0.00 sec)
MySQL's graphic Korean chart is here: euckr.
B.11.9: Why do I get
For illustration, we'll create a table with one Unicode (ucs2) column and one Chinese (gb2312)
column.
mysql> CREATE TABLE ch
-> (ucs2 CHAR(3) CHARACTER SET ucs2,
-> gb2312 CHAR(3) CHARACTER SET gb2312);
Query OK, 0 rows affected (0.05 sec)
We'll try to place the rare character
mysql> INSERT INTO ch VALUES ('A汌B','A汌B');
Query OK, 1 row affected, 1 warning (0.00 sec)
Ah, there is a warning. Use the following statement to see what it is:
NOT SIGN
(3F is the question mark ("?")—this is what is always used when the conversion
in
sjis
U+20A9
Incorrect string value
汌
in both columns.
2896
ucs2
00AC
FFE2
(Unicode U+00AC) to
sjis
to cp932?
81CA
becomes
81CA (FULLWIDTH NOT SIGN)
5C
(Extended Unix Code Korea) character
euckr
is REVERSE SOLIDUS, that is
0x5c
to euckr:
error messages?
sjis
81CA
3F
code point
0x81CA
in cp932.
and euc) treat
sjis
is the Yen sign, as at least
is SIGN(₩). This
0x5c WON
cp932
3F
81CA
and to
as
5C