From a6f6942288f674a902de77220d030e8cb4d81f6a Mon Sep 17 00:00:00 2001
From: mike12345567 <me@michaeldrury.co.uk>
Date: Thu, 3 Oct 2024 16:10:07 +0100
Subject: [PATCH] Fixing an issue with corrupt relationship records referencing
 rows which don't exist, this is a temporary measure as these relationships
 should be cleaned up correctly but for now ignore any which reference rows
 which no longer exist.

---
 .../backend-core/src/db/couch/DatabaseImpl.ts | 12 +++++++----
 .../src/db/linkedRows/LinkController.ts       | 20 ++++++++++---------
 packages/types/src/sdk/db.ts                  |  2 +-
 3 files changed, 20 insertions(+), 14 deletions(-)

diff --git a/packages/backend-core/src/db/couch/DatabaseImpl.ts b/packages/backend-core/src/db/couch/DatabaseImpl.ts
index 274c1b9e93..472e0f44ad 100644
--- a/packages/backend-core/src/db/couch/DatabaseImpl.ts
+++ b/packages/backend-core/src/db/couch/DatabaseImpl.ts
@@ -213,17 +213,21 @@ export class DatabaseImpl implements Database {
 
   async getMultiple<T extends Document>(
     ids: string[],
-    opts?: { allowMissing?: boolean }
+    opts?: { allowMissing?: boolean; excludeDocs?: boolean }
   ): Promise<T[]> {
     // get unique
     ids = [...new Set(ids)]
+    const includeDocs = !opts?.excludeDocs
     const response = await this.allDocs<T>({
       keys: ids,
-      include_docs: true,
+      include_docs: includeDocs,
     })
     const rowUnavailable = (row: RowResponse<T>) => {
       // row is deleted - key lookup can return this
-      if (row.doc == null || ("deleted" in row.value && row.value.deleted)) {
+      if (
+        (includeDocs && row.doc == null) ||
+        (row.value && "deleted" in row.value && row.value.deleted)
+      ) {
         return true
       }
       return row.error === "not_found"
@@ -237,7 +241,7 @@ export class DatabaseImpl implements Database {
       const missingIds = missing.map(row => row.key).join(", ")
       throw new Error(`Unable to get documents: ${missingIds}`)
     }
-    return rows.map(row => row.doc!)
+    return rows.map(row => (includeDocs ? row.doc! : row.value))
   }
 
   async remove(idOrDoc: string | Document, rev?: string) {
diff --git a/packages/server/src/db/linkedRows/LinkController.ts b/packages/server/src/db/linkedRows/LinkController.ts
index 85a160713b..3c0601c9ee 100644
--- a/packages/server/src/db/linkedRows/LinkController.ts
+++ b/packages/server/src/db/linkedRows/LinkController.ts
@@ -211,19 +211,21 @@ class LinkController {
             linkedSchema?.type === FieldType.LINK &&
             linkedSchema?.relationshipType === RelationshipType.ONE_TO_MANY
           ) {
-            let links = (
-              await getLinkDocuments({
-                tableId: field.tableId,
-                rowId: linkId,
-              })
-            ).filter(
-              link =>
-                link.id !== row._id && link.fieldName === linkedSchema.name
+            let links = await getLinkDocuments({
+              tableId: field.tableId,
+              rowId: linkId,
+              fieldName: linkedSchema.name,
+            })
+
+            // check all the related rows exist
+            const foundRecords = await this._db.getMultiple(
+              links.map(l => l.id),
+              { allowMissing: true, excludeDocs: true }
             )
 
             // The 1 side of 1:N is already related to something else
             // You must remove the existing relationship
-            if (links.length > 0) {
+            if (foundRecords.length > 0) {
               throw new Error(
                 `1:N Relationship Error: Record already linked to another.`
               )
diff --git a/packages/types/src/sdk/db.ts b/packages/types/src/sdk/db.ts
index a081f4f1a2..49baaa5bb1 100644
--- a/packages/types/src/sdk/db.ts
+++ b/packages/types/src/sdk/db.ts
@@ -133,7 +133,7 @@ export interface Database {
   exists(docId: string): Promise<boolean>
   getMultiple<T extends Document>(
     ids: string[],
-    opts?: { allowMissing?: boolean }
+    opts?: { allowMissing?: boolean; excludeDocs?: boolean }
   ): Promise<T[]>
   remove(idOrDoc: Document): Promise<Nano.DocumentDestroyResponse>
   remove(idOrDoc: string, rev?: string): Promise<Nano.DocumentDestroyResponse>