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  • PJBS for Python

    From =?UTF-8?Q?Arne_Vajh=C3=B8j?=@21:1/5 to All on Sun Jan 19 14:35:07 2025
    There is a PJBS open source project at:
    https://sourceforge.net/projects/pjbs/
    which has been forked at:
    https://github.com/JCotton1123/php-jdbc-bridge

    It allows PHP applications to access a database using a
    JDBC driver.

    It works like:

    PHP app with PJBridge class-->proxy process with JDBC driver-->database

    PJBridge.php is very simple so it was easy to convert to Python:

    Python app with PJBridge class-->proxy process with JDBC driver-->database

    And I even created a DB API 2.0 layer on top of it to be more Pythonesque:

    Python app with PJBS and PJBridge classes-->proxy process with JDBC driver-->database

    And it seems to work reasonable well.

    There are a few things to be aware:
    * data are always returned as string so numeric data need to be
    manual converted.
    * no support for database transaction
    * I have not tested error handling or performance
    * very limited functional testing so lot of stuff may be missing
    (feel free to add it!)

    This tool is not particular interesting on common platforms like
    Linux and Windows as both PHP and Python has drivers for almost
    all databases available there.

    But it is a bit more interesting on VMS as a driver for VMS
    is not a top priority for most language projects and
    database vendors. But the database vendors usually
    provide a type 4 JDBC driver. A type 4 JDBC driver is a pure
    Java JDBC driver, which means that you can copy the jar file
    from Linux/Windows to VMS and it works.

    So with:

    portable PHP/Python API-->portable Java proxy-->portable type 4 JDBC driver

    it all works even if the language project and the database vendor has
    not even heard about VMS!

    And this is not just theory. I have tested with:
    - MySQL
    - PostgreSQL
    - Oracle DB - thin
    - IBM DB2
    - MS SQLServer
    - SQLite (*)
    - Derby
    - H2
    - HSQLDB

    And previously I have tested PJBS with:
    - Rdb - native (*)
    - Rdb - thin
    - Mimer

    *) Type 2 not type 4 so VMS version required!

    I would group them in:
    * PHP/Python drivers available (or will be available) on VMS: MySQL, PostgreSQL, SQLite
    * not interesting for PHP/Python developers (they will prefer SQLIte):
    Derby, H2, HSQLDB
    * potential relevance of PJBS: Oracle DB, IBM DB2, MS SQLServer

    If anyone want to play with it then it is available at:
    https://www.vajhoej.dk/arne/vmsstuff/pjbs/

    Arne

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  • From Lawrence D'Oliveiro@21:1/5 to All on Sun Jan 19 22:26:41 2025
    On Sun, 19 Jan 2025 14:35:07 -0500, Arne Vajhøj wrote:

    But it is a bit more interesting on VMS as a driver for VMS is not a top priority for most language projects and database vendors. But the
    database vendors usually provide a type 4 JDBC driver. A type 4 JDBC
    driver is a pure Java JDBC driver, which means that you can copy the jar
    file from Linux/Windows to VMS and it works.

    If they have a client library for C, say, then you should be able to
    create a pure-Python wrapper around it using ctypes.

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  • From =?UTF-8?Q?Arne_Vajh=C3=B8j?=@21:1/5 to Lawrence D'Oliveiro on Sun Jan 19 19:47:46 2025
    On 1/19/2025 5:26 PM, Lawrence D'Oliveiro wrote:
    On Sun, 19 Jan 2025 14:35:07 -0500, Arne Vajhøj wrote:
    But it is a bit more interesting on VMS as a driver for VMS is not a top
    priority for most language projects and database vendors. But the
    database vendors usually provide a type 4 JDBC driver. A type 4 JDBC
    driver is a pure Java JDBC driver, which means that you can copy the jar
    file from Linux/Windows to VMS and it works.

    If they have a client library for C, say, then you should be able to
    create a pure-Python wrapper around it using ctypes.

    There are some possibilities for some databases.

    MS SQLServer is probably the easiest. I believe FreeTDS can build
    on VMS and pymssql can use FreeTDS, so someone just need to figure
    everything out on how to make it build on VMS. Also as fallback
    the TDS protocol is known (FreeTDS and jTDS) and a pure Python
    solution (using TCP to port 1433) could be developed. All that
    is required is some work.

    Oracle DB client lib (OCI not to be confused with OCI!) was
    available in an old version on older VMS platforms, but
    will not be available on VMS x86-64. So that seems like
    a dead end future wise. Then there are the commercial ODBC
    solutions.

    IBM DB2 client lib has never been available on VMS AFAIK.
    That leaves commercial ODBC solutions, if they support DB2,
    which is far from a given.

    Then there is the SQLRelay solution. There are both PHP
    and Python clients for that. They could be ported to
    VMS. Again just work. But that is also with a proxy
    and even though SQLRelay proxy is a way more robust and
    supported solution than PJBS, then it does not even run
    on VMS - it has to run on Linux or Windows.

    Compared to that:
    * translating 123 lines of PHP to 61 lines of Python
    * write 46 lines of Python to get DB API 2.0 API
    is dirt cheap to get all 3 working!!

    But if someone has a serious need for like MS SQLServer
    access, then they should be able to make it work.

    Arne

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  • From Lawrence D'Oliveiro@21:1/5 to All on Mon Jan 20 01:21:11 2025
    On Sun, 19 Jan 2025 19:47:46 -0500, Arne Vajhøj wrote:

    ... then it does not even run on VMS - it has to run on Linux or
    Windows.

    Imagine if VSI had followed the strategy I suggested those years ago, to
    simply get rid of the VMS kernel, keeping just DCL and the userland APIs,
    and reimplementing those on top of Linux. So many vistas would be open now
    that are otherwise shut.

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  • From Simon Clubley@21:1/5 to Lawrence D'Oliveiro on Mon Jan 20 13:36:00 2025
    On 2025-01-19, Lawrence D'Oliveiro <ldo@nz.invalid> wrote:
    On Sun, 19 Jan 2025 19:47:46 -0500, Arne Vajhøj wrote:

    ... then it does not even run on VMS - it has to run on Linux or
    Windows.

    Imagine if VSI had followed the strategy I suggested those years ago, to simply get rid of the VMS kernel, keeping just DCL and the userland APIs,
    and reimplementing those on top of Linux. So many vistas would be open now that are otherwise shut.

    As you have already been told, people have done exactly that. Multiple times. And yet there is still a need for "real" VMS or VSI would never have existed.

    Simon.

    --
    Simon Clubley, clubley@remove_me.eisner.decus.org-Earth.UFP
    Walking destinations on a map are further away than they appear.

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  • From =?UTF-8?Q?Arne_Vajh=C3=B8j?=@21:1/5 to All on Sun Jan 26 12:46:28 2025
    On 1/19/2025 2:35 PM, Arne Vajhøj wrote:
    PJBridge.php is very simple so it was easy to convert to Python:

    Python app with PJBridge class-->proxy process with JDBC driver-->database

    And I even created a DB API 2.0 layer on top of it to be more Pythonesque:

    Python app with PJBS and PJBridge classes-->proxy process with JDBC driver-->database

    And it seems to work reasonable well.

    If anyone want to play with it then it is available at:
      https://www.vajhoej.dk/arne/vmsstuff/pjbs/

    I have update the ZIP with a few small changes needed
    to make it work with Python 2 as well (VMS Alpha).

    Arne

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