feat: EXPOSED-403 Implement `EntityClass.restriction` - a means of providing soft deletes

bystam commented 3 weeks ago

This is my attempt at showcasing/drafting a version of "DAO restrictions", similarly to how @SQLRestriction works in Hibernate (which can be used for soft deletes), but without the magic annotation setup.

Youtrack: https://youtrack.jetbrains.com/newIssue?project=EXPOSED&draftId=25-5413167

Usage:

object BlogPosts : LongIdTable() {
  val text = text("text")
  val isDeleted = bool("is_deleted").default(false)
}

class BlogPost(id: EntityID<Long>) : LongIdEntity(id) {
  var text: String by BlogPosts.text

  override fun delete() {
      // instead of regular hard delete, override it to simply "mark as deleted"
      BlogPosts.update({ BlogPosts.id eq id }) {
          it[isDeleted] = true
      }
  }

  companion object : LongIdEntityClass<BlogPost>(BlogPosts) {
    // this will automatically make sure only non-deleted BlogPost entities show up
    override val restriction: Op<Boolean> = BlogPosts.isDeleted eq false
  }
}

val post = BlogPost.new {
  text = "Nice blog"
}
post.delete()

BlogPost.all() // 0 elements

val actual = PostPosts.selectAll().single() // but will show up in DB

Why "restriction"?

It matches what the Hibernate equivalent is called
Anything called "base predicate" or "base filter" doesn't really capture that it will always be applied in an AND <restriction> fashion, in my mind

bystam commented 3 weeks ago

I have one test failure on Sqlite, and looking more closely at it, it feels light it might be a separate SQLite-oriented bug perhaps?

The table/entity pair is declared like this - where requestId is the id column of the entity

I noticed when running SQL logging that the following: seems to perform soft delete on the wrong ID:

SQL: INSERT INTO Requests (requestId) VALUES ('123')
SQL: UPDATE Requests SET deleted_at='2024-06-07 07:11:38.703' WHERE Requests.requestId = '1'

and indeed, the Entity instance seems to have been given the wrong ID:

bystam commented 3 weeks ago

Bug has been filed and reproduced in tests here:

obabichevjb commented 3 weeks ago

Thank you for PR, it looks interesting, I'll create an issue in YouTrack for the discussion of it,

Also thank you for describing the bug, I checked another PR and related YT issue, here (/pull/2119) is a PR that should fix it.

bystam commented 2 weeks ago

Thank you for PR, it looks interesting, I'll create an issue in YouTrack for the discussion of it,

I have one here: https://youtrack.jetbrains.com/issue/EXPOSED-403/DAO-soft-delete-restriction-support Unless you meant something else :)

JetBrains / Exposed

feat: EXPOSED-403 Implement `EntityClass.restriction` - a means of providing soft deletes #2114

Why "restriction"?