[asp.net] ORA-12154 could not resolve the connect identifier specified

I have switched over to the 64bit Windows 7 and created a simple web app to test the connection to the database. I am using VS 2010 - plain asp.net web project and I am running the application from within VS.

I am getting this error: "ORA-12154 could not resolve the connect identifier specified"

I also have a sample console application that tests the connection to the database, and it works fine.

After googling it some, I found that a lot of posts online refered to permissions so I set my C:/Oracle permissions to read/write/execute for my ASP.net account, NETWORK SERVICE, COMPUTER NAME. That still won't solve the issue. I checked that my web app runs under my domain\username account and that this account that the rights to read/write/execute to the C:\Oracle folder.

I even re-installed my VS to make sure that it is in C:\Program Files rather than C:\Program Files(x86)

Any ideas to why my web app doesn't see the connection string? (while the console app does) Not sure what else I can do.

This question is related to asp.net oracle

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Another obnoxious error type I've encountered in Oracle 11: entries in tnsnames.ora that don't begin at the first column of the line (' XXX=(...)' instead of 'XXX=(...)') and are parsed together with the preceding entry, making it malformed.

Like replaced orr misplaced tnsnames.ora files, this type of problem is easy to diagnose with the tnsping command-line utility: you pass it the name of a tnsnames.ora entry and it gives the complete text of its definition.


This is an old question but Oracle's latest installers are no improvement, so I recently found myself back in this swamp, thrashing around for several days ...

My scenario was SQL Server 2016 RTM. 32-bit Oracle 12c Open Client + ODAC was eventually working fine for Visual Studio Report Designer and Integration Services designer, and also SSIS packages run through SQL Server Agent (with 32-bit option). 64-bit was working fine for Report Portal when defining and Testing an Data Source, but running the reports always gave the dreaded "ORA-12154" error.

My final solution was to switch to an EZCONNECT connection string - this avoids the TNSNAMES mess altogether. Here's a link to a detailed description, but it's basically just: host:port/sid

http://www.oracledistilled.com/oracle-database/oracle-net/using-easy-connect-ezconnect-naming-method-to-connect-to-oracle-databases/

In case it helps anyone in the future (or I get stuck on this again), here are my Oracle install steps (the full horror):

Install Oracle drivers: Oracle Client 12c (32-bit) plus ODAC.

a. Download and unzip the following files from http://www.oracle.com/technetwork/database/enterprise-edition/downloads/database12c-win64-download-2297732.html and http://www.oracle.com/technetwork/database/windows/downloads/utilsoft-087491.html ):

i. winnt_12102_client32.zip

ii. ODAC112040Xcopy_32bit.zip

b. Run winnt_12102_client32\client32\setup.exe. For the Installation Type, choose Admin. For the installation location enter C:\Oracle\Oracle12. Accept other defaults.

c. Start a Command Prompt “As Administrator” and change directory (cd) to your ODAC112040Xcopy_32bit folder.

d. Enter the command: install.bat all C:\Oracle\Oracle12 odac

e. Copy the tnsnames.ora file from another machine to these folders: *

i. C:\Oracle\Oracle12\network\admin *

ii. C:\Oracle\Oracle12\product\12.1.0\client_1\network\admin *

Install Oracle Client 12c (x64) plus ODAC

a. Download and unzip the following files from http://www.oracle.com/technetwork/database/enterprise-edition/downloads/database12c-win64-download-2297732.html and http://www.oracle.com/technetwork/database/windows/downloads/index-090165.html ):

i. winx64_12102_client.zip

ii. ODAC121024Xcopy_x64.zip

b. Run winx64_12102_client\client\setup.exe. For the Installation Type, choose Admin. For the installation location enter C:\Oracle\Oracle12_x64. Accept other defaults.

c. Start a Command Prompt “As Administrator” and change directory (cd) to the C:\Software\Oracle Client\ODAC121024Xcopy_x64 folder.

d. Enter the command: install.bat all C:\Oracle\Oracle12_x64 odac

e. Copy the tnsnames.ora file from another machine to these folders: *

i. C:\Oracle\Oracle12_x64\network\admin *

ii. C:\Oracle\Oracle12_x64\product\12.1.0\client_1\network\admin *

* If you are going with the EZCONNECT method, then these steps are not required.

The ODAC installs are tricky and obscure - thanks to Dan English who gave me the method (detailed above) for that.


I have an Entity Framework web application that works on my local machine, but this error appears when pushed to another environment. There are other non-Entity Framework applications that work, and I'm able to connect with sqlplus.

Using sysinternals Process Monitor shows that tns names file is not being loaded correctly:

tnsnames.ora status NAME NOT FOUND

Following the documentation I tried to add a section giving the location of the tnsnames file like so:

<configuration>

  <configSections>
    <section name="oracle.manageddataaccess.client"
      type="OracleInternal.Common.ODPMSectionHandler, Oracle.ManagedDataAccess, Version=4.122.1.0, Culture=neutral, PublicKeyToken=89b483f429c47342"/>
  </configSections>
  
  <oracle.manageddataaccess.client>
    <version number="*">
      <settings>
        <setting name="TNS_ADMIN" value="C:\Oracle\product\12.1.0\client_1\Network\Admin"/>
      </settings>
    </version>
  </oracle.manageddataaccess.client>
  
<configuration>

However, this resulted in an immediate 500 server error.

Further investigation showed that the dll I was packaging with the web application was version 4.122.1.0, while the Oracle client environment installed on the machine was 4.121.2.0. As explained in the Oracle EntityFramework package documentation

Note: If your application is a web application and the above entry was added to a web.config and the same config section handler for "oracle.manageddataaccess.client" also exists in machine.config but the "Version" attribute values are different, an error message of "There is a duplicate 'oracle.manageddataaccess.client' section defined." may be observed at runtime. If so, the config section handler entry in the machine.config for "oracle.manageddataaccess.client" has to be removed from the machine.config for the web application to not encounter this error. But given that there may be other applications on the machine that depended on this entry in the machine.config, this config section handler entry may need to be moved to all of the application's .NET config file on that machine that depend on it.

I attempted to add a separate version section in the .NET machine.config without success (there existed a section for version 4.121.2.0 and I added a section for version 4.122.1.0). After I removed the "oracle.manageddataaccess.client" section from the machine.config, the above addition to the web.config resolved ORA-12154.

Solution #1 summary:

  1. Remove "oracle.manageddataaccess.client" from .NET machine.config
  2. Give TNS_ADMIN configuration setting in web.config as above

Solution 2

While researching this problem I found that the TNS_ADMIN environmental variable was not set. I created a new environmental variable called TNS_ADMIN and set the value to "C:\Oracle\product\12.1.0\client_1\Network\Admin". I removed the web.config changes, and removed the "oracle.manageddataaccess.client" section from .NET machine.config, but still received ORA-12154. Only after I restarted the machine did this resolve the issue.

Solution #2 summary:

  1. Create a new environmental variable called TNS_ADMIN and set the value to "C:\Oracle\product\12.1.0\client_1\Network\Admin"
  2. Restart machine

Solution 3

I added an entry for the correct version in the registry and this resolved the issue:

HKLM\Software\Wow6432Node\Oracle\ODP.NET.Managed\4.121.2.0  

The name of the key is TNS_ADMIN and this points to the folder containing the tnsnames file:

C:\Oracle\product\12.1.0\client_1\network 

Not the C:\Oracle\product\12.1.0\client_1\network\admin folder.


In my case, the reason for this error was that I was missing the tnsnames.ora file under client_32\NETWORK\ADMIN


This error (and also ORA-6413: Connection not open) can also be caused by parentheses in the application executable path and a bug in the 10.2.0.1 or lower oracle client libraries.

You should either upgrade your oracle client library or change the executable path.

Further details see:


I had the same issue. In my case I was using a web service which was build using AnyCPU settings. Since the WCF was using 32 bit Oracle data access components therefore it was raising the same error when I tried to call it from a console client. So when I compiled the WCF service using the x86 based setting the client was able to successfully get data from the web service.

If you compile as "Any CPU" and run on an x64 platform, then you won't be able to load 32-bit dlls (which in our case were the Oracle Data Access components), because our app wasn't started in WOW64 (Windows32 on Windows 64). So in order to allow the 32 bit dependency of Oracle Data Access components I compilee the web service with Platform target of x86 and that solved it for me

As an alternative if you have 64bit ODAC drivers installed on the machine that also caused the problem to go away.


If you are using LDAP, make sure that the environment variable "TNS_ADMIN" exists and points to the folder containing the file "ldap.ora".

If this variable does not exist, create it and restart Visual Studio.


Please let me repeat what Stephen said since I missed it the first time myself. The TNS_ADMIN environment variable and ORACLE_HOME is set to C:\instantclient_11_2 and th tnsnames.ora file is in there. Found the answer on this link.


use process monitor and search for name not found log for tnsnames.ora file.

check your environment variables. if not valid than uninstall all oracle client and reinstall.


Had a similar issue, only my web app was fine and it was SQLPlus that was giving me issues connecting, and the ORA-12154 could not resolve the connect identifier specified error. I had 11g and 12 Oracle clients installed. My environment variables were all set to point at my 12 instance:

  • ORACLE_HOME = C:\oracle\product\12
  • PATH = C:\oracle\product\12\bin;....
  • TNS_ADMIN = C:\oracle\product\12\network\admin

There is also a registry entry required at HKLM\Software\Oracle\KEY_OraClient12Home1, a string entry of TNS_ADMIN with the same path as the environment variable.

I have a tnsnames.ora at both C:\oracle\product\11\network\admin and C:\oracle\product\12\network\admin. As far as I know, both my web app and the 12 SQLPlus client I was using should have been using all 12 version variables.

My troubleshooting steps:

  • Change all environmental variables above from 12 to 11.
  • Connect with 11g's SQLPlus (worked!)
  • Change all environmental variables above back from 11 to 12.
  • Connect with 12's SQLPlus again (worked!)

So I don't really know what caused 12's SQLPlus to stop connecting, but this kind of reset may work for someone, so thought I'd document it here.


I had this error in Visual Studio 2013, with an SSIS project. I set Project, Properties, Debugging, Run64BitRuntime = false and then the SSIS package ran. However, when I deployed the package to the server I had to set the value to true (Server is 64 bit Windows 2012 / Sql 2014 ).

I think the reasoning behind this is that Visual Studio is a 32 bit application.


I am going to assume you are using the tnsnames.ora file to specify your available database services. If so connection errors usually come down to two things.

  1. The application cannot find the TNS entry you specified in the connection string.

  2. The TNS entry was found, but the IP or host is not correct in the tnsnames.ora file.

To expand on number 1 (which I think is your problem). When you tell Oracle to connect using something like:

sqlplus user/pass@service

The service is defined in the tnsnames.ora file. If I attempt to connect with a service that is not defined in my tnsnames.ora, I get the error you get:

[sodonnel@home ~]$ sqlplus sodonnel/sodonnel@nowhere

SQL*Plus: Release 11.2.0.1.0 Production on Mon Oct 31 21:42:15 2011

Copyright (c) 1982, 2009, Oracle.  All rights reserved.

ERROR:
ORA-12154: TNS:could not resolve the connect identifier specified

So you need to check a few things:

  1. Is there a tnsnames.ora file - I think yes because your console can connect
  2. Is there an entry in the file for the service - I think also yes as the console connects
  3. Can the application find the tnsnames.ora?

Your problem may well be number 3 - does the application run as a different user than when you run the console?

Oracle looks for the tnsnames.ora file in the directory defined in the TNS_ADMIN environment variable - If you are running as different users, then maybe the TNS_ADMIN environment variable is not set, and therefore it cannot find the file?


Use this link.on Microsoft Support

I gave permission to IUSR_MachineName user on oracle home folder and I was able to resolve the problem


There can be so many issues but if you are using oracle 10g , uninstall oracle 10g and also remove the value from registry and install oracle 11g. But if you are using oracle 11g , first go and check on registry if it is pointing to right home. Sometimes there can be more than one home because you install sql developer again and again . In that case either you can remove unnecessary home registry value or you can add tns and sql.net file to all of those home, that might resolve the issue. I resolved mine in that way.