Re: operator does not exist: text = bytea - Mailing list pgsql-general

From Karthik K L V
Subject Re: operator does not exist: text = bytea
Date
Msg-id CAGpQzhzUDPrktZp5EidGXnS=C2fjM4CYDh5gP8=0Qn6bC0Nt9A@mail.gmail.com
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In response to Re: operator does not exist: text = bytea  (hubert depesz lubaczewski <depesz@depesz.com>)
List pgsql-general
Hi  depesz,

Thanks for your reply. But, this issue is happening only when the bind value of the query resolves to null. I am not trying to compare text to bytes.
And the same query works fine when the bind value gets resolves to some String. So, looking for an option which can tell Postgres Engine to read = null as is null.

On Wed, Jul 20, 2022 at 5:29 PM hubert depesz lubaczewski <depesz@depesz.com> wrote:
On Wed, Jul 20, 2022 at 03:02:13PM +0530, Karthik K L V wrote:
> *Caused by: org.postgresql.util.PSQLException: ERROR: operator does not
> exist: text = bytea  Hint: No operator matches the given name and argument
> types. You might need to add explicit type casts.  Position: 1037*
> Could you please let me know how I can resolve this issue without making
> changes to the query?

I don't think it's possible.

bytea is basically array of bytes.
text on the other hand is array of characters.

Do the bytes "\xbf\xf3\xb3\x77" equal text "żółw"?

They actually kinda do, if we assume the bytes are text in encoding
Windows-1252 - in which case the bytes mean "żółw".

But if we'd assume the encoding to be, for example, iso8859-1, then the
same sequence of bytes means "¿ó³w"

That's why you can't compare bytes to characters.

You have to either convert bytes to text using convert or convert_from
functions, or change text into bytea using convert_to.

In some cases you can simply cast text to bytea:

$ select 'depesz'::text::bytea;
     bytea     
────────────────
 \x64657065737a
(1 row)

which will work using current server encoding, afair.

depesz


--
Karthik klv

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