Oracle - add/edit connection dialog forces hostname input - conflicts with Oracle Network Connection

[Jean-Roc]

Description

Creating or editing an Oracle connection with the data source manager is not possible with a version > 3.10.x, the validation control is greyed out

How to Reproduce

1. Go to Data Source manager > Oracle
2. Create or edit a connection
3. Set all the required parameters and test the connection
4. Try to click the button "OK" to save or update the connection

QGIS and OS versions

Last version tested that works -> 3.10.3
Last version tested -> 3.15.0-Master 9305e22
Other versions tested 3.12 3.14

[uclaros]

It's working fine for me, I'm on 02f5c13 on Linux Debian.
The OK button is greyed out only if I have not completed the Database field.

[Jean-Roc]

@uclaros here is the same connection on 3.15 (left) and 3.10 (right)

[uclaros]

Your host field is empty, if it's a local connection just enter localhost

[Jean-Roc]

Filling it with localhost will trigger an error with the client : ORA-12154 : TNS: could not resolve the connect identifier specified, these parameters were used at least since QGIS 2.x. Most of the configuration is done through a single common file where all the hosts and ports are defined.

[uclaros]

Can you connect if you supply the host address, the database, the port,, the schema and credentials?

[Jean-Roc]

If I fill in the hostname I'll get the aforementioned ORA :

• 3.10.x no host but connection possible
• 3.12 - 3.15 no host and connection impossible

When I provide an hostname such as localhost in QGIS, it conflicts with the one set in the ADDRESS_LIST / HOST of the *.ora file of our organization. If I add manually the correct hostname, it would connect but then if the IT admin change it in the global file it would break all the connections.

[uclaros]

So if I get this right, the problem is that you are unable to connect using tnsnames.ora instead of host/port/database?
The Oracle equivalent of #38197 ?
Could you adjust the title accordingly, if so?

[Jean-Roc]

The contrary : forcing to specify the host conflicts with tnsname.ora, I'm able to connect if I leave the host field blank (in 3.10 and earlier).

[troopa81]

It's related to #35838 but the main issue is that there is no service field in oracle new connection dialog like there is in Postgres. For now, if you didn't set a host the database name was considered as a service name. But since #35838 the check prevents from setting database name without an host, which is quite normal.

I'll propose a PR to fix this.