Re: How to display stored image as bytea or as large objects?

Csanyi Pal <csanyipal@xxxxxxxxx> · Thu, 15 Jul 2021 06:12:09 +0200

2021. 07. 14. 22:17 keltezéssel, Ho John Lee írta:
If you have the binary data for the image in the bytea field, DBeaver 
will display the image when you select that field in table view of the data.
The field will display something like "ÿØÿà  JFIF   [nnnnn]" in the row 
(first part of data as unicode, and data length in bytes), you won't see 
the image unless you put focus on it.

I will try this, but do not know which SQL code will store an image in a 
bytea data type column?

Could you give such SQL code please?

At the moment I have stored image in an oid data type column.

.--hjl

On Wed, Jul 14, 2021 at 12:57 PM Csanyi Pal <csanyipal@xxxxxxxxx 
<mailto:csanyipal@xxxxxxxxx>> wrote:

    Hi,

    I am a novice in postgresql language.

    By reading the documentation about storing binary data in postgresql
    database, I realize that that one can store images as binary data by
    using bytea or BLOB data types.

    I am running postgresql on Ubuntu 20.04.2 LTS and using pgAdmin4 in
    Desktop mode.

    I have stored an image in one of my table with this command:

    <code>
    insert into leckek
    (az, a_tanitas_nyelve, mely_negyedevben, mely_osztalyban,
    mely_tagozaton, mely_orakon, a_tanitas_temaja,
       a_lecke_neve, a_lecke_gyakorlati_reszenek_neve,
    a_lecke_gyakorlati_reszenek_dokumentuma,
       a_lecke_elmeleti_reszenek_neve,
    a_lecke_elmeleti_reszenek_dokumentuma,
    a_lecke_elmeleti_reszenek_tesztje)
    values (default, 'Hu', 1, 5, 'b', '1-2', 'Élet és mukakörnyezet',
                     'A technika és technológia fogalma, szerepe és
    jelentősége',
                     'másolás',
                     default,
                     'A lényeg',

    lo_import('/home/pali/Irataim/Iskola/IskolaEv_2020_2021/MuszakiOraim/Digitalis_Tananyagok_Orakra/Hu/5/5_osztaly_Tananyag_01_02_orara.png'),
                     default)
    </code>

    so I have now in this table the first row:
    1       "Hu"    1       5       "b"     "1-2  " "Élet és
    mukakörnyezet" "A technika és
    technológia fogalma, szerepe és jelentősége"    "másolás"           
        "A lényeg"      "16800"

    Here the 16800 is the OID of the binary data, the image.

    I would like to know how can one display this stored image somehow by
    using some IDE for manage databases?

    In applications like pgAdmin4, Libreoffice Base, pgModeler, DBeaver one
    can't display this stored image.

    In SQLiteBrowser (this is an IDE for SQLite databases) one can display
    with easy the stored image.

    So is there an easy way to display a stored image in postgresql?

    --
    Best,
    from Paul