Fix generics model pointers for updates and add Join method

[MarlinKuhn]

• Do only one thing
• Non breaking API changes
• Tested

What did this pull request do?

Fixes #7713

User Case Description

If you use generics and want to use the Set to update values on a model with hooks it fails currently.

[propel-code-bot]

Add generic Join support and fix model pointer usage in generics

This PR adds a new Join method to the generics chain API and introduces the ExternalJoinBuilder interface, enabling external joins with ON conditions built from a scoped builder. It also adjusts join table handling when jt.Table is empty or clause.CurrentTable, and refines Count to avoid Select("*") when a column is not specified.

Additionally, several generics update/create paths now pass a pointer model via new(T) to Model(...), fixing update/Set flows that require model hooks to run properly.

Key Changes

• Added Join to ChainInterface[T] with a new ExternalJoinBuilder interface for building external join conditions in generics.go
• Updated Joins and Join to normalize jt.Table when empty or equal to clause.CurrentTable
• Switched generics update/create/association operations to use new(T) for Model(...) in Update, Set updates, Create, and association operations
• Adjusted Count to only call Select when a non-empty, non-* column is provided

Affected Areas

• generics.go
• ChainInterface[T] API
• JoinBuilder and new ExternalJoinBuilder behavior
• Generics update/create/association flows

This summary was automatically generated by @propel-code-bot

[propel-code-bot]

Join handling may drop subqueries, requiring adjustment for correctness.

Status: Changes Suggested | Risk: Medium

Issues Identified & Suggestions

• Handle subquery joins in Join to avoid silent drops: generics.go

Review Details

📁 1 files reviewed | 💬 1 comments

👍 / 👎 individual comments to help improve reviews for you

[propel-code-bot]

[Logic] Join ignores jt.Subquery. If callers use JoinTarget.AssociationFrom or populate Subquery, this will silently drop the subquery and join on jt.Association as a table name. Is that intentional? If subquery joins should work here, add handling similar to Joins (building join.Expression with a NamedExpr over jt.Subquery).

Context for Agents

`Join` ignores `jt.Subquery`. If callers use `JoinTarget.AssociationFrom` or populate `Subquery`, this will silently drop the subquery and join on `jt.Association` as a table name. Is that intentional? If subquery joins should work here, add handling similar to `Joins` (building `join.Expression` with a `NamedExpr` over `jt.Subquery`).

File: generics.go
Line: 452

[propel-code-bot]

Review found no issues with the proposed changes.

Status: No Issues Found | Risk: Low

Review Details

📁 1 files reviewed | 💬 0 comments