From 5581705bbeb656b79a73d51dce8166a7f68dbfe9 Mon Sep 17 00:00:00 2001
From: Brandon Williams <mbrandonw@hey.com>
Date: Fri, 9 Jan 2026 13:15:54 -0600
Subject: [PATCH 1/2] Fix for schema migration involving 'NOT NULL' columns.

---
 Sources/SQLiteData/CloudKit/SyncEngine.swift  |  4 +--
 .../CloudKitTests/SchemaChangeTests.swift     | 36 +++++++++++++++++++
 2 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/Sources/SQLiteData/CloudKit/SyncEngine.swift b/Sources/SQLiteData/CloudKit/SyncEngine.swift
index 5d094197..da96ec9d 100644
--- a/Sources/SQLiteData/CloudKit/SyncEngine.swift
+++ b/Sources/SQLiteData/CloudKit/SyncEngine.swift
@@ -2005,11 +2005,11 @@
               if data == nil {
                 reportIssue("Asset data not found on disk")
               }
-              return "\(quote: columnName) = \(data?.queryFragment ?? "NULL")"
+              return "\(quote: columnName) = \(data?.queryFragment ?? #""excluded".\#(quote: columnName)"#)"
             } else {
               return """
                 \(quote: columnName) = \
-                \(record.encryptedValues[columnName]?.queryFragment ?? "NULL")
+                \(record.encryptedValues[columnName]?.queryFragment ?? #""excluded".\#(quote: columnName)"#)
                 """
             }
           }
diff --git a/Tests/SQLiteDataTests/CloudKitTests/SchemaChangeTests.swift b/Tests/SQLiteDataTests/CloudKitTests/SchemaChangeTests.swift
index 38315932..4bbcc62e 100644
--- a/Tests/SQLiteDataTests/CloudKitTests/SchemaChangeTests.swift
+++ b/Tests/SQLiteDataTests/CloudKitTests/SchemaChangeTests.swift
@@ -106,6 +106,42 @@
         }
       }
 
+      @available(iOS 17, macOS 14, tvOS 17, watchOS 10, *)
+      @Test func addColumn_OldRecordsSyncToNewSchema() async throws {
+        let remindersList = RemindersList(id: 1, title: "Personal")
+        try await userDatabase.userWrite { db in
+          try db.seed {
+            remindersList
+          }
+        }
+        try await syncEngine.processPendingRecordZoneChanges(scope: .private)
+
+        syncEngine.stop()
+
+        try await userDatabase.userWrite { db in
+          try #sql(
+            """
+            ALTER TABLE "remindersLists" 
+            ADD COLUMN "position" INTEGER NOT NULL ON CONFLICT REPLACE DEFAULT 0
+            """
+          )
+          .execute(db)
+        }
+
+        let relaunchedSyncEngine = try await SyncEngine(
+          container: syncEngine.container,
+          userDatabase: syncEngine.userDatabase,
+          tables: syncEngine.tables
+            .filter { $0.base != Reminder.self && $0.base != RemindersList.self }
+            + [
+              SynchronizedTable(for: ReminderWithPosition.self),
+              SynchronizedTable(for: RemindersListWithPosition.self),
+            ],
+          privateTables: syncEngine.privateTables
+        )
+        defer { _ = relaunchedSyncEngine }
+      }
+
       @available(iOS 17, macOS 14, tvOS 17, watchOS 10, *)
       @Test func addAssetToRemindersList() async throws {
         let personalList = RemindersList(id: 1, title: "Personal")

From 01daefb43993452cd6fc0214018673500abefd96 Mon Sep 17 00:00:00 2001
From: Brandon Williams <mbrandonw@hey.com>
Date: Fri, 9 Jan 2026 13:19:36 -0600
Subject: [PATCH 2/2] wip

---
 .../CloudKitTests/SchemaChangeTests.swift              | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/Tests/SQLiteDataTests/CloudKitTests/SchemaChangeTests.swift b/Tests/SQLiteDataTests/CloudKitTests/SchemaChangeTests.swift
index 4bbcc62e..f9fc85c6 100644
--- a/Tests/SQLiteDataTests/CloudKitTests/SchemaChangeTests.swift
+++ b/Tests/SQLiteDataTests/CloudKitTests/SchemaChangeTests.swift
@@ -106,6 +106,12 @@
         }
       }
 
+      /*
+       * Old schema creates record and synchronizes to iCloud.
+       * Schema is migrated to add a "NOT NULL" column.
+       * New sync engine is launched.
+       => Sync starts without emitting an error.
+       */
       @available(iOS 17, macOS 14, tvOS 17, watchOS 10, *)
       @Test func addColumn_OldRecordsSyncToNewSchema() async throws {
         let remindersList = RemindersList(id: 1, title: "Personal")
@@ -128,7 +134,8 @@
           .execute(db)
         }
 
-        let relaunchedSyncEngine = try await SyncEngine(
+        // NB: Sync engine should start without emitting issue.
+        _ = try await SyncEngine(
           container: syncEngine.container,
           userDatabase: syncEngine.userDatabase,
           tables: syncEngine.tables
@@ -139,7 +146,6 @@
             ],
           privateTables: syncEngine.privateTables
         )
-        defer { _ = relaunchedSyncEngine }
       }
 
       @available(iOS 17, macOS 14, tvOS 17, watchOS 10, *)