Add support for derived relations in XMLDB and remove obsolete relations file

[harshil8595]

Hi @grabs

I can't reopen existing PR

Add foreign key links support for component tables following componentname_object pattern

After the addition of foreign links support, I tested the feature with Moodle plugins tables and noticed an edge case related to tables belonging to components.

Currently, object table relations are automatically populated when column names match the pattern {object}id and a corresponding {object} table exists. For example, columns named courseid correctly link to the course table.

However, Moodle plugin tables follow a different naming convention:

componentname_object

For example:

• Table: tool_customlang
• Related table: tool_customlang_components
• Field: componentid
• Expected relation: tool_customlang.componentid → tool_customlang_components.id

This relation is defined in Moodle’s install.xml:

<KEY NAME="fk_component" TYPE="foreign" FIELDS="componentid"
     REFTABLE="tool_customlang_components" REFIELDS="id"/>

But currently, Adminer does not automatically generate links for such component-based tables.

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Steps to reproduce

1. Visit
   {yourmoodle}/admin/tool/customlang/index.php

2. Select a language

3. Click
   Open language pack for editing

4. Open table in adminer
   tool_customlang

5. Observe field
   componentid

Expected result:
componentid should display links to records in tool_customlang_components

Actual result:
No relation link is shown

---

Proposed improvement

This PR extends the foreign link detection logic to support Moodle plugin table naming conventions:

componentname_object

This ensures relations such as:

tool_customlang.componentid → tool_customlang_components.id

are correctly detected and linked.

---

Benefits

This significantly improves debugging and developer productivity by allowing Moodle developers to:

• Navigate table relations faster
• Inspect related records directly
• Debug database issues more efficiently

This is especially useful because Moodle defines logical foreign keys in XML but does not enforce them at the database level.

---

I am happy to make further improvements or adjustments based on your feedback.

[harshil8595]

Hi @grabs

I understand you may be busy, but I would really appreciate it if you could take a look when you have some time.

Please let me know if any changes or additional information are needed from my side. I’d be happy to update the PR accordingly.

Thank you for your time and for maintaining this project.

[grabs]

Hello, thank you very much for this useful addition!
I’ve made a few small adjustments and simplified the code a bit.
In my opinion, a function should ideally not return different data types.
The comments were also not entirely consistent.
But as I said, these were only minor things.
Thanks again for your work!

[harshil8595]

Hi @grabs ,

Thanks for your time and efforts.

[harshil8595]

Hi @grabs,

Can you add me as contributor in this plugin on moodle.org?

I've messaged you my moodle userid to your moodle account.

It will be grealy appreciated