feat: use path expressions on new dbs

CHANGELOG.md

@@ -4,6 +4,12 @@ All notable changes to this project will be documented in this file.
 This project adheres to [Semantic Versioning](http://semver.org/).
 The format is based on [Keep a Changelog](http://keepachangelog.com/).
 
+## Version 0.8.3 - 2024-11-28
+
+### Fixed
+
+- Rewrite subselects to use path expressions on @cap-js databases
+
 ## Version 0.8.2 - 2024-11-27
 
 ### Fixed

lib/utils.js

@@ -141,7 +141,7 @@ const _buildSubSelect = (model, { entity, relative, element, next }, row, previo
   return childCqn
 }
 
-const _getDataSubjectIdQuery = ({ dataSubjectEntity, subs }, row, model) => {
+const _old_getDataSubjectIdQuery = ({ dataSubjectEntity, subs }, row, model) => {
   const keys = Object.values(dataSubjectEntity.keys)
   const as = _alias(dataSubjectEntity)
 
@@ -156,6 +156,84 @@ const _getDataSubjectIdQuery = ({ dataSubjectEntity, subs }, row, model) => {
   return cqn
 }
 
+const _getRelation = (left, right, abort) => {
+  let a
+  for (const assoc in left.associations) {
+    if (left.associations[assoc].target === right.name) {
+      a = left.associations[assoc]
+      break
+    }
+  }
+  if (a) return { base: left, target: right, assoc: a }
+  return abort ? undefined : _getRelation(right, left, true)
+}
+
+const _new_getDataSubjectIdQuery = ({ dataSubjectEntity, subs }, row) => {
+  const qs = []
+
+  // multiple subs => entity reused in different branches => must check all
+  for (const sub of subs) {
+    const path = []
+    let s = sub
+    while (s) {
+      if (!path.length) {
+        // the known entity instance as starting point
+        const kp = Object.keys(s.entity.keys).reduce((acc, cur) => {
+          if (cur !== 'IsActiveEntity') acc.push(`${cur}='${row[cur]}'`)
+          return acc
+        }, [])
+        path.push({ id: s.entity.name, where: kp })
+      }
+
+      let relation = _getRelation(s.entity, s.next?.entity || dataSubjectEntity)
+      if (!relation) {
+        // TODO: no relation found
+      } else if (relation.base === s.entity) {
+        // assoc in base
+        if (relation.assoc === s.element) {
+          // forwards
+          path.push({ to: relation.assoc.name })
+        } else {
+          // backwards
+          path[0].id = s.element.name
+          path.unshift({ id: relation.target.name })
+        }
+      } else {
+        // assoc in target
+        path[0].id = s.element.name
+        path.unshift({ id: relation.base.name })
+      }
+
+      s = s.next
+    }
+
+    // construct path as string
+    const p = path.reduce((acc, cur) => {
+      if (!acc) {
+        acc += `${cur.id}${cur.where ? `[${cur.where.join(' and ')}]` : ''}`
+      } else {
+        if (cur.id) {
+          const close = acc.match(/([\]]+)$/)?.[1]
+          if (close)
+            acc =
+              acc.slice(0, close.length * -1) +
+              `[exists ${cur.id}${cur.where ? `[${cur.where.join(' and ')}]` : ''}]` +
+              close
+          else acc += `[exists ${cur.id}${cur.where ? `[${cur.where.join(' and ')}]` : ''}]`
+        } else if (cur.to) acc += `.${cur.to}`
+      }
+      return acc
+    }, '')
+
+    qs.push(SELECT.one.from(p).columns(...Object.keys(dataSubjectEntity.keys)))
+  }
+
+  // merge queries, if necessary
+  const q = qs[0]
+  for (let i = 1; i < qs.length; i++) q.SELECT.from.ref[0].where.push('or', ...qs[i].SELECT.from.ref[0].where)
+  return q
+}
+
 const _getUps = (entity, model) => {
   if (entity.own($parents) == null) {
     const ups = []
@@ -246,7 +324,12 @@ const addDataSubjectForDetailsEntity = (row, log, req, entity, model) => {
   const map = _getDataSubjectsMap(req)
   if (map.has(role)) log.data_subject.id = map.get(role)
   // REVISIT by downward lookups row might already contain ID - some potential to optimize
-  else map.set(role, _getDataSubjectIdQuery(dataSubjectInfo, row, model))
+  else {
+    module.exports._getDataSubjectIdQuery ??= cds.env.requires.db?.impl?.startsWith('@cap-js/')
+      ? _new_getDataSubjectIdQuery
+      : _old_getDataSubjectIdQuery
+    map.set(role, module.exports._getDataSubjectIdQuery(dataSubjectInfo, row, model))
+  }
 }
 
 const resolveDataSubjects = (logs, req) => {

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@cap-js/audit-logging",
-  "version": "0.8.2",
+  "version": "0.8.3",
   "description": "CDS plugin providing integration to the SAP Audit Log service as well as out-of-the-box personal data-related audit logging based on annotations.",
   "repository": "cap-js/audit-logging",
   "author": "SAP SE (https://www.sap.com)",