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From: Zhongpu Chen <chenloveit@gmail.com>
Date: Sat, 2 May 2026 00:09:19 +0800
Message-ID: <CA+1gyqJMtuTofZDy+CeomGGhsFGXw6JrdyAhqvnLii44oKePGg@mail.gmail.com>
Subject: Re: Character with byte sequence 0xa2 0xa3 in encoding "EUC_CN" has
 no equivalent in encoding "UTF8"
To: Junwang Zhao <zhjwpku@gmail.com>
Cc: pgsql-bugs@lists.postgresql.org
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Archived-At: <https://www.postgresql.org/message-id/CA%2B1gyqJMtuTofZDy%2BCeomGGhsFGXw6JrdyAhqvnLii44oKePGg%40mail.gmail.com>
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```
demo_euc_cn_db=3D# SET client_encoding TO 'EUC_CN';
SET
demo_euc_cn_db=3D# SELECT * FROM t WHERE id =3D 1;
 id | s
----+----
  1 | =EF=BF=BD=EF=BF=BD
(1 row)
```

Since 0xA2A3 is invalid in EUC-CN, it cannot be mapped to any meaningful
character. Currently, EUC-CN allows all 2-byte within A1-EF, but this
coarse-grained approach is flawed.

On Fri, May 1, 2026 at 11:07=E2=80=AFPM Junwang Zhao <zhjwpku@gmail.com> wr=
ote:

> On Fri, May 1, 2026 at 9:59=E2=80=AFPM Zhongpu Chen <chenloveit@gmail.com=
> wrote:
> >
> > ## Description
> >
> > The legacy encodings allow some invalid bytes, which will cause errors
> during SELECT operations.
> >
> > ## How to reproduce
> >
> > ```shell
> > createdb -E EUC_CN -T template0 --locale=3DC demo_euc_cn_db
> > ```
> >
> > ```sql
> > demo_euc_cn_db=3D# CREATE TABLE t(id int, s varchar(10));
> >
> > demo_euc_cn_db=3D# INSERT INTO t VALUES(1, E'\xA2\xA3');
> > INSERT 0 1
> > demo_euc_cn_db=3D# SELECT * FROM t WHERE id =3D 1;
> > ERROR:  character with byte sequence 0xa2 0xa3 in encoding "EUC_CN" has
> no equivalent in encoding "UTF8"
>
> Can you try the following statement before select?
> SET client_encoding TO 'EUC_CN';
>
> > ```
> >
> > --
> > Zhongpu Chen
>
>
>
> --
> Regards
> Junwang Zhao
>


--=20
Zhongpu Chen

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<div dir=3D"ltr"><div><br></div><div>```</div><div>demo_euc_cn_db=3D# SET c=
lient_encoding TO &#39;EUC_CN&#39;;<br>SET<br>demo_euc_cn_db=3D# SELECT * F=
ROM t WHERE id =3D 1;<br>=C2=A0id | s<br>----+----<br>=C2=A0 1 | =EF=BF=BD=
=EF=BF=BD<br>(1 row)</div><div>```</div><div><br></div><div>Since 0xA2A3 is=
 invalid in EUC-CN, it cannot be mapped to any meaningful character. Curren=
tly, EUC-CN allows all 2-byte within A1-EF, but this coarse-grained approac=
h is flawed.</div></div><br><div class=3D"gmail_quote gmail_quote_container=
"><div dir=3D"ltr" class=3D"gmail_attr">On Fri, May 1, 2026 at 11:07=E2=80=
=AFPM Junwang Zhao &lt;<a href=3D"mailto:zhjwpku@gmail.com">zhjwpku@gmail.c=
om</a>&gt; wrote:<br></div><blockquote class=3D"gmail_quote" style=3D"margi=
n:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex=
">On Fri, May 1, 2026 at 9:59=E2=80=AFPM Zhongpu Chen &lt;<a href=3D"mailto=
:chenloveit@gmail.com" target=3D"_blank">chenloveit@gmail.com</a>&gt; wrote=
:<br>
&gt;<br>
&gt; ## Description<br>
&gt;<br>
&gt; The legacy encodings allow some invalid bytes, which will cause errors=
 during SELECT operations.<br>
&gt;<br>
&gt; ## How to reproduce<br>
&gt;<br>
&gt; ```shell<br>
&gt; createdb -E EUC_CN -T template0 --locale=3DC demo_euc_cn_db<br>
&gt; ```<br>
&gt;<br>
&gt; ```sql<br>
&gt; demo_euc_cn_db=3D# CREATE TABLE t(id int, s varchar(10));<br>
&gt;<br>
&gt; demo_euc_cn_db=3D# INSERT INTO t VALUES(1, E&#39;\xA2\xA3&#39;);<br>
&gt; INSERT 0 1<br>
&gt; demo_euc_cn_db=3D# SELECT * FROM t WHERE id =3D 1;<br>
&gt; ERROR:=C2=A0 character with byte sequence 0xa2 0xa3 in encoding &quot;=
EUC_CN&quot; has no equivalent in encoding &quot;UTF8&quot;<br>
<br>
Can you try the following statement before select?<br>
SET client_encoding TO &#39;EUC_CN&#39;;<br>
<br>
&gt; ```<br>
&gt;<br>
&gt; --<br>
&gt; Zhongpu Chen<br>
<br>
<br>
<br>
-- <br>
Regards<br>
Junwang Zhao<br>
</blockquote></div><div><br clear=3D"all"></div><br><span class=3D"gmail_si=
gnature_prefix">-- </span><br><div dir=3D"ltr" class=3D"gmail_signature"><d=
iv dir=3D"ltr">Zhongpu Chen</div></div>

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