Re: Bytea Example - Mailing list pgsql-general

On 8/16/20 10:10 AM, Naveen Kumar wrote:
> sorry for the late reply. Below is my issue:
> 
> I am connected to PostgreSQL in a Windows environment. Below is my version:
> 
> *"PostgreSQL 12.3, compiled by Visual C++ build 1914, 64-bit"*
> 
> I am just trying to practice LOB objects, like byteA data type, in 
> PostgreSQL. Unfortunately, I didn't find good links regarding this so I 
> raised the issue. Nothing else I am doing.

Some simple examples:

create table bytea_test(byte_fld bytea);

insert into bytea_test values('\xDEADBEEF');

select * from bytea_test ;
   byte_fld
------------
  \xdeadbeef

insert into bytea_test values(decode('test string', 'escape'));

select * from bytea_test ;
          byte_fld
--------------------------
  \xdeadbeef
  \x7465737420737472696e67

select encode(byte_fld, 'escape') from bytea_test ;
       encode
------------------
  \336\255\276\357
  test string

 From docs:

https://www.postgresql.org/docs/12/datatype-binary.html

https://www.postgresql.org/docs/12/functions-binarystring.html

As pointed out by Francisco Olarte the above generally does not happen 
directly in database. Usually you are using some external program to 
convert the binary data into some form of bytea.

> 
> Thank you one and all !!
> 
> Thanks & Regards
> Naveen
> 
> 
> 
> On Thu, Aug 13, 2020 at 7:34 PM Adrian Klaver <adrian.klaver@aklaver.com 
> <mailto:adrian.klaver@aklaver.com>> wrote:
> 
>     On 8/13/20 6:56 AM, Naveen Kumar wrote:
>      > I am not using any programming language. I am simply using
>     PostgreSQL 12
>      > version that's all
> 
>     I'm having a hard time figuring out how you are migrating from
>     Oracle to
>     Postgres without using at least SQL and some sort of driver to pull out
>     of one and push into the other.
> 
>      >
>      > On Thu, Aug 13, 2020 at 7:21 PM Adrian Klaver
>     <adrian.klaver@aklaver.com <mailto:adrian.klaver@aklaver.com>
>      > <mailto:adrian.klaver@aklaver.com
>     <mailto:adrian.klaver@aklaver.com>>> wrote:
>      >
>      >     On 8/13/20 6:49 AM, Naveen Kumar wrote:
>      >      > I am trying to migrate the database from Oracle to PostgreSQL
>      >
>      >     The question was:
>      >
>      >     What programming language and database driver are you using?
>      >
>      >      >
>      >      > On Thu, Aug 13, 2020 at 7:17 PM Adrian Klaver
>      >     <adrian.klaver@aklaver.com <mailto:adrian.klaver@aklaver.com>
>     <mailto:adrian.klaver@aklaver.com <mailto:adrian.klaver@aklaver.com>>
>      >      > <mailto:adrian.klaver@aklaver.com
>     <mailto:adrian.klaver@aklaver.com>
>      >     <mailto:adrian.klaver@aklaver.com
>     <mailto:adrian.klaver@aklaver.com>>>> wrote:
>      >      >
>      >      >     On 8/13/20 6:40 AM, Naveen Kumar wrote:
>      >      >      > Can someone please give me an example on byteA data
>     type.
>      >      >      >
>      >      >      > 1. How to import a image/text file into Bytea data
>     type.?
>      >      >      > 2. How to export the same?
>      >      >
>      >      >     What programming language and database driver are you
>     using?
>      >      >
>      >      >     --
>      >      >     Adrian Klaver
>      >      > adrian.klaver@aklaver.com
>     <mailto:adrian.klaver@aklaver.com> <mailto:adrian.klaver@aklaver.com
>     <mailto:adrian.klaver@aklaver.com>>
>      >     <mailto:adrian.klaver@aklaver.com
>     <mailto:adrian.klaver@aklaver.com> <mailto:adrian.klaver@aklaver.com
>     <mailto:adrian.klaver@aklaver.com>>>
>      >      >
>      >
>      >
>      >     --
>      >     Adrian Klaver
>      > adrian.klaver@aklaver.com <mailto:adrian.klaver@aklaver.com>
>     <mailto:adrian.klaver@aklaver.com <mailto:adrian.klaver@aklaver.com>>
>      >
> 
> 
>     -- 
>     Adrian Klaver
>     adrian.klaver@aklaver.com <mailto:adrian.klaver@aklaver.com>
> 


-- 
Adrian Klaver
adrian.klaver@aklaver.com