Getting PL/SQL Developer on Windows 7 64bit to connect to an Oracle database

After I installed the latest version of PL/SQL Developer on my Windows 7 64bit machine today, I got the following error message when trying to connect to an Oracle database: 

Initialization error
Could not initialize "D:\oracle\product\11.2.0\client_1\bin\oci.dll"
Make sure you have the 32 bits Oracle Client installed.
PL/SQL Developer Windows 7 64bit Oci Error

As I’ve found out, the solution is to install (actually, simply extracting the archive is enough) the latest 32bit version of the Oracle Instant Client and configure PL/SQL Developer to use it instead of the 64bit Oracle client under Tools – Preferences.

PL/SQL Developer Windows 7 64bit Settings

I found this solution here: Fix Initialization Error: LoadLibrary oci.dll returned 0 while trying to connect to Oracle using PL/SQL Developer.

However, PL/SQL Developer didn’t recognize my tnsnames.ora anymore after I switched to the 32bit Instant Client. The solution is pretty simple: just create the directory network\admin in the 32bit Instant Client’s directory and copy your tnsnames.ora from the real Oracle client’s directory there.

Über Stefan

Polyglot Clean Code Developer

11 Kommentare

  1. Wael
    12. Januar 2012 um 16:33:18

    It worked great! I even didn’t change in tnsnames.ora. thanks for the blog!

  2. archie
    2. März 2012 um 10:07:42

    Thanks, that was very fast and helpful

  3. Mariana
    9. Mai 2012 um 21:07:25

    Hi!
    I had the same problem
    I juts did what you said. It worked once, when I firs logged in yesterday!
    But today, I tried to log in again, there was de following message error:
    “ORA-12514 TNS:listener does not currently know of service requested in connect descriptor.”
    Do you know what can I do to solve it?

    Best regards,

    Mary

  4. Andi
    30. Juni 2012 um 20:19:16

    Great it works! Many Thanks 🙂

  5. VungThung
    10. Juli 2012 um 6:14:44

    Thanks for Good friend!
    It works for me!

  6. Robert
    7. November 2012 um 14:14:45

    Great tip. Keep up the good work!
    Tks.
    Rob

  7. Pedro
    6. Februar 2013 um 20:21:46

    I´ve followed these steps, I already can see the databases of the tnsnames.ora file in the database combobox, but when I try to connect to some database I´m getting an error: ORA-12705: Cannot access NLS data files or invalid environment specified.

    What should I do?

  8. Igor
    17. März 2013 um 7:07:49

    Thank you, it works just fine.

  9. Arun
    14. Mai 2013 um 10:12:12

    Thanks a lot.. Its working fine now 🙂

  10. Ajit
    27. Oktober 2016 um 13:23:24

    Awesome information…Don’t need to install complete DB client. Just extract this instant client, create folders and copy tns and sql net files. configure oci .dll path in PL SQL Developer preferences. That’s it. Thanks a ton…!!

  11. Stefan
    27. Oktober 2016 um 15:50:57

    You’re welcome! 🙂

Schreibe einen Kommentar

Deine E-Mail-Adresse wird nicht veröffentlicht. Erforderliche Felder sind mit * markiert

To create code blocks or other preformatted text, indent by four spaces:

    This will be displayed in a monospaced font. The first four 
    spaces will be stripped off, but all other whitespace
    will be preserved.
    
    Markdown is turned off in code blocks:
     [This is not a link](http://example.com)

To create not a block, but an inline code span, use backticks: 

Here is some inline `code`.

For more help see http://daringfireball.net/projects/markdown/syntax