Fix overwrite get_uri for Oracle

[guan404ming]

Related Issue

Towards #38195

Why

The base DbApiHook.get_uri incorrectly assumes that Airflow connection URI representation is a valid SQLAlchemy URI, but this is not always true, especially for complex cases. For Oracle connections, the URI format needs to handle various connection scenarios including SID, service name, and PDB configurations.

This PR implements a proper get_uri method for the OracleHook class, ensuring that Oracle connection URIs are correctly formatted according to Oracle's connection string requirements.

How

• Implements the get_uri method in OracleHook to properly generate Oracle connection URIs
• Handles different Oracle connection scenarios:
• Adds parametrized unit tests to validate URI generation for various configurations

Ref: https://docs.oracle.com/en/database/other-databases/essbase/21/essoa/connection-string-formats.html

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[h30306]

LGTM

[guan404ming]

Thanks for your reviewing, I have updated the PR with you suggestion!

[Lee-W]

left one nit, almost good to merge 👍

[jason810496]

Nice! Thanks for the PR.

[guan404ming]

Thanks for reviewing!

[cjbj]

@guan404ming @Lee-W @h30306 This (merged) PR raised some questions. If get_uri() is for "a valid SQLAlchemy URI" then the change in the MR:

uri = f"oracle://{login}:{password}@{host}:{port}"
if sid:
    uri = f"{uri}/{sid}"
elif service_name:
    uri = f"{uri}/{service_name}"
elif conn.schema:
    uri = f"{uri}/{conn.schema}"

may not be correct since it doesn't follow documented SQLAlchemy connection syntax for the python-oracledb driver.

• Since airflow 3 now uses python-oracledb, the URI should begin with oracle+oracledb: otherwise the obsolete cx_Oracle driver would be needed.

• SQLAlchemy needs service names to be prefixed with ?service_name=.

• Service names are the new way forward (as of a few decades ago), so service_name should be first choice, not sid in the if/else block.

• I forget the history of Airflow and schemas, so can't comment on whether the final elif block needs some tweaks to be valid SQLAlchemy syntax.

Code should be like:

uri = f"oracle+oracledb://{login}:{password}@{host}:{port}"
if service_name:
    uri = f"{uri}?service_name={service_name}"
elif sid:
    uri = f"{uri}/{sid}"
# and maybe this, depending what is in conn.schema????    
#elif conn.schema:
#    uri = f"{uri}/{conn.schema}"

[guan404ming]

Thanks for pointing out, I've open a PR for the fix. Please take another look if available, thanks!