Feature Add Oracle driver

[ytetsuro]

Description
I wanted to use CodeIgniter4 in an Oracle environment.
Also, it was determined that support would be provided because ORACLE was described in the document.

Checklist:

• Securely signed commits
• Component(s) with PHPdocs
• Unit testing, with >80% coverage
• User guide updated
• Conforms to style guide

The design of the program to get the insertId of this PR is not so good.

Please good solution.

[lonnieezell]

Thanks so much for submitting this! You rock for that. I won't be able to get to this until after the next RC release, honestly. Besides reviewing this, we need to get Travis setup to be able to test it if possible. I'm honestly not familiar enough with Oracle to know if there's a simple to setup community version. Looks like there's Express Edition but would have to look deeper to see if we could integrate.

[ytetsuro]

@lonnieezell
Thanks feedback.

Looks like there's Express Edition but would have to look deeper to see if we could integrate.

Humm...
it may be difficult.

oracle/docker-images#1156

Is there anything I can do to help with the this review?

[yogahilmi]

I tried using this driver with Oracle 18C, it works fine.

Thank you @ytetsuro

[kenjis]

@ytetsuro @lonnieezell
This repo has GitHub workflows with Oracle image.
https://github.com/yiisoft/db-oracle

[michalsn]

I was working on tests for this at some point and the main problem I had, was how to set an empty database because by default oracle comes with a lot of additional tables that break our tests. Also, I think we need at least Oracle 12 to support "auto-increment" values.

Maybe this thing with a fresh database is trivial but my DevOps skills are low 😅

[jkashwin]

Any update on the availability of OCI8 driver support for CI4 ?

[javawebmedia]

I am really waiting for this Codeigniter 4 Oracle driver. Hopefully, it can be released soon. Thank you

[ytetsuro]

@kenjis

This repo has GitHub workflows with Oracle images.

Very thanks.

Using the same idea, I checked the containers used in version 12c and above and found that quillbuilduser/oracle-18-xe was used.

The following repositories use this container.

• https://github.com/getquill/quill
• https://github.com/knex/knex/blob/01cfa98c2cdd9d2f8c91320d4551efdaa1768d21/scripts/docker-compose.yml
• https://github.com/JetBrains/Exposed/blob/b6d00e51062c91c6b23a89de55f900e2e4f24225/buildScripts/docker/docker-compose-oracle.yml

@lonnieezell
@kenjis

we need to get Travis setup to be able to test it if possible

Changed GitHub Actions so that the OCI8 tests work with the above container.
Please review.

[kenjis]

@ytetsuro @lonnieezell @michalsn @jkashwin @javawebmedia
What version of Oracle Database should this driver support?
12.1+?
12.2+?
18c+?
other?

And we need to add about this driver in
https://codeigniter4.github.io/CodeIgniter4/intro/requirements.html

[ytetsuro]

@kenjis

Thanks for the quick feedback.

What version of Oracle Database should this driver support?

I think 12.1+.
I used the following version of this driver when I created it.

• 12.1
• 18c

The driver I created this time doesn't seem to use any of the features that were deprecated in 18c, so I think 12.1+ is fine.

https://docs.oracle.com/en/database/oracle/oracle-database/18/upgrd/behavior-change-deprecate-desupport-oracle-12c-rel-2.html#GUID-3BAFD95E-4D00-4F0F-BC80-6064F497F878

And we need to add about this driver in

Thanks.
I added it for now.

[kenjis]

Database Driver abstracts Database operations, and this is the same for CodeIgniter4.

I'm not sure CI4 aims to Database Driver abstraction.
If we aim to it, we cannot use any Database specific functionality,
and cannot add any Database Driver specific functionality to a specific driver.
We should remove callFunction(), because it does not work if a user changes the database.

Personally I think abstraction is Query Builder (and CodeIgniter\Model) and Forge.
And Stored Procedure is not so rare functionality, but not all databases have it.
It might be possible that BaseConnection has storedProcedure().

2. stop using original prepared statements when using OCI, and use a class that uses oci_bind_by_name to create queries.

I don't get what you mean. What is original prepared statements ?

[ytetsuro]

@kenjis

Thanks for feedback.

I'm learning a lot. Thank you.

I'm not sure CI4 aims to Database Driver abstraction.
If we aim to it, we cannot use any Database specific functionality,
and cannot add any Database Driver specific functionality to a specific driver.

Indeed, I don't think we should add it!

I thought that inheriting from BaseConnection meant that I was abstracting the Database connection.
I don't think we should do that even as a Liskov substitution principle.
If it is to be a subclass of BaseConnection.

However, the idea that you should use PDO if you want abstraction may also exist...

We should remove callFunction(), because it does not work if a user changes the database.
Personally I think abstraction is Query Builder (and CodeIgniter\Model) and Forge.

I don't know why there is a callFunction that can only return boolean.
However, as you said, abstraction may not be the goal when there are callFunction and query methods.

Thank you. I learned a lot and understand.

And Stored Procedure is not so rare functionality, but not all databases have it.
It might be possible that BaseConnection has storedProcedure().

It's true that storedProcedure is not an ORACLE-specific feature.
MySQL can call storedProcedure in a CALL statement via the query method.
In OCI, I think we need to prepare a separate storedProcedure method because we need to allocate variables of reference and resource types.
I think because the binding process for prepared statements is a proprietary implementation.
This is because references and resource types can only be bound using functions such as oci_bind_by_name.

From the above, I feel that it would be better to implement it in 2.
What do you think?

I don't get what you mean. What are original prepared statements?

I'm sorry.
My explanation was not good.
I meant to stop the original binding implementation for prepared statement.
Specifically, we are considering whether it would be possible to design the binding process in the Query class so that the PreparedQuery class is used for binding.
By doing so, we believe that users will be able to execute storedProcedure in the query method, just like in MySQL.

[kenjis]

$ vendor/bin/rector process file1 file2 ...
$ composer cs-fix

[kenjis]

I would like to release Oracle driver with functionality that can upgrade CI 3.1 code to 4.x as soon as possible.
If we can execute stored procedures by the query() method, Does it provide value to the Oracle users?

[ytetsuro]

@kenjis

Thanks for feedback!

If we can execute stored procedures by the query() method, Does it provide value to the Oracle users?

No.

I can't offer much value in being able to run storedProcedure in the query method.
However, I think I can provide value in stopping proprietary bindings.
For example, it will be able to store binary data.
Being able to execute storedProcedure from the query method is one such example.

https://www.php.net/manual/en/function.oci-bind-by-name.php#example-1789

I would like to release Oracle driver with functionality that can upgrade CI 3.1 code to 4.x as soon as possible.

It might be a good idea to try to release it at this point and make it possible to do it in query, and then gently remove unnecessary methods in the 4.3 release.

[kenjis]

@ytetsuro I don't fully understand your 2. plan, but it seems a good way to go.

But this PR is too long living and I really want to finish it.
Refactoring or improvements can be added later.

Can you fix the coding style error?

[kenjis]

LGTM

[ytetsuro]

@kenjis

Thank you very much for supporting this PR for a very long time.

I don't fully understand your 2. plan, but it seems a good way to go.

I understood.
I would like to issue an issue with more details on this content when this PR is merged.

Thank you very much!!

[kenjis]

The one of the oldest, and most commented PR has been merged!