Support multiple upsert clauses

moor/lib/src/runtime/api/batch.dart

@@ -37,7 +37,7 @@ class Batch {
   /// See also:
   ///  - [InsertStatement.insert], which would be used outside a [Batch].
   void insert<T extends Table, D>(TableInfo<T, D> table, Insertable<D> row,
-      {InsertMode? mode, DoUpdate<T, D>? onConflict}) {
+      {InsertMode? mode, UpsertClause<T, D>? onConflict}) {
     _addUpdate(table, UpdateKind.insert);
     final actualMode = mode ?? InsertMode.insert;
     final context = InsertStatement<Table, D>(_user, table)
@@ -59,7 +59,7 @@ class Batch {
   /// support it. For details and examples, see [InsertStatement.insert].
   void insertAll<T extends Table, D>(
       TableInfo<T, D> table, List<Insertable<D>> rows,
-      {InsertMode? mode, DoUpdate<T, D>? onConflict}) {
+      {InsertMode? mode, UpsertClause<T, D>? onConflict}) {
     for (final row in rows) {
       insert<T, D>(table, row, mode: mode, onConflict: onConflict);
     }

moor/lib/src/runtime/query_builder/statements/insert.dart

@@ -61,7 +61,7 @@ class InsertStatement<T extends Table, D> {
   Future<int> insert(
     Insertable<D> entity, {
     InsertMode? mode,
-    DoUpdate<T, D>? onConflict,
+    UpsertClause<T, D>? onConflict,
   }) async {
     final ctx = createContext(entity, mode ?? InsertMode.insert,
         onConflict: onConflict);
@@ -81,7 +81,7 @@ class InsertStatement<T extends Table, D> {
   /// this method, make sure that you have a recent sqlite3 version available.
   /// This is the case with `sqlite3_flutter_libs`.
   Future<D> insertReturning(Insertable<D> entity,
-      {InsertMode? mode, DoUpdate<T, D>? onConflict}) async {
+      {InsertMode? mode, UpsertClause<T, D>? onConflict}) async {
     final ctx = createContext(entity, mode ?? InsertMode.insert,
         onConflict: onConflict, returning: true);
 
@@ -113,7 +113,7 @@ class InsertStatement<T extends Table, D> {
   ///
   /// This method is used internally by moor. Consider using [insert] instead.
   GenerationContext createContext(Insertable<D> entry, InsertMode mode,
-      {DoUpdate<T, D>? onConflict, bool returning = false}) {
+      {UpsertClause<T, D>? onConflict, bool returning = false}) {
     _validateIntegrity(entry);
 
     final rawValues = entry.toColumns(true);
@@ -148,7 +148,7 @@ class InsertStatement<T extends Table, D> {
       writeInsertable(ctx, map);
     }
 
-    if (onConflict != null) {
+    void writeDoUpdate(DoUpdate<T, D> onConflict) {
       final upsertInsertable = onConflict._createInsertable(table.asDslTable);
 
       if (!identical(entry, upsertInsertable)) {
@@ -194,6 +194,12 @@ class InsertStatement<T extends Table, D> {
       }
     }
 
+    if (onConflict is DoUpdate<T, D>) {
+      writeDoUpdate(onConflict);
+    } else if (onConflict is UpsertMultiple<T, D>) {
+      onConflict.clauses.forEach(writeDoUpdate);
+    }
+
     if (returning) {
       ctx.buffer.write(' RETURNING *');
     }
@@ -278,11 +284,17 @@ const _insertKeywords = <InsertMode, String>{
   InsertMode.insertOrIgnore: 'INSERT OR IGNORE',
 };
 
+/// A upsert clause controls how to behave when a uniqueness constraint is
+/// violated during an insert.
+///
+/// Typically, one would use [DoUpdate] to run an update instead in this case.
+abstract class UpsertClause<T extends Table, D> {}
+
 /// A [DoUpdate] upsert clause can be used to insert or update a custom
 /// companion when the underlying companion already exists.
 ///
 /// For an example, see [InsertStatement.insert].
-class DoUpdate<T extends Table, D> {
+class DoUpdate<T extends Table, D> extends UpsertClause<T, D> {
   final Insertable<D> Function(T old) _creator;
 
   /// An optional list of columns to serve as an "conflict target", which
@@ -299,3 +311,19 @@ class DoUpdate<T extends Table, D> {
     return _creator(table);
   }
 }
+
+/// Upsert clause that consists of multiple [clauses].
+///
+/// The first [DoUpdate.target] matched by this upsert will be run.
+class UpsertMultiple<T extends Table, D> extends UpsertClause<T, D> {
+  /// All [DoUpdate] clauses that are part of this upsert.
+  ///
+  /// The first clause with a matching [DoUpdate.target] will be considered.
+  final List<DoUpdate<T, D>> clauses;
+
+  /// Creates an upsert consisting of multiple [DoUpdate] clauses.
+  ///
+  /// This requires a fairly recent sqlite3 version (3.35.0, released on 2021-
+  /// 03-12).
+  UpsertMultiple(this.clauses);
+}

moor/test/insert_test.dart

@@ -4,7 +4,6 @@ import 'package:test/test.dart';
 
 import 'data/tables/todos.dart';
 import 'data/utils/mocks.dart';
-import 'skips.dart';
 
 void main() {
   late TodoDb db;
@@ -93,7 +92,7 @@ void main() {
         {const TableUpdate('users', kind: UpdateKind.insert)}));
 
     expect(user.id, 5);
-  }, skip: onNoReturningSupport());
+  });
 
   group('enforces integrity', () {
     test('for regular inserts', () async {
@@ -206,6 +205,37 @@ void main() {
     ));
   });
 
+  test(
+    'can use multiple upsert targets',
+    () async {
+      await db
+          .into(db.todosTable)
+          .insert(TodosTableCompanion.insert(content: 'my content'),
+              onConflict: UpsertMultiple([
+                DoUpdate(
+                  (old) {
+                    return TodosTableCompanion.custom(
+                        content: const Variable('important: ') + old.content);
+                  },
+                ),
+                DoUpdate(
+                  (old) {
+                    return TodosTableCompanion.custom(
+                        content: const Variable('second: ') + old.content);
+                  },
+                  target: [db.todosTable.content],
+                ),
+              ]));
+
+      verify(executor.runInsert(
+        'INSERT INTO todos (content) VALUES (?) '
+        'ON CONFLICT(id) DO UPDATE SET content = ? || content '
+        'ON CONFLICT(content) DO UPDATE SET content = ? || content',
+        argThat(equals(['my content', 'important: ', 'second: '])),
+      ));
+    },
+  );
+
   test('can use a custom conflict clause', () async {
     await db.into(db.todosTable).insert(
           TodosTableCompanion.insert(content: 'my content'),

moor/test/integration_tests/insert_integration_test.dart

@@ -38,5 +38,5 @@ void main() {
         priority: CategoryPriority.low,
       ),
     );
-  }, skip: onNoReturningSupport());
+  }, skip: ifOlderThanSqlite335());
 }

moor/test/integration_tests/moor_files_integration_test.dart

@@ -118,5 +118,5 @@ void main() {
         ),
       );
     });
-  }, skip: onNoReturningSupport());
+  }, skip: ifOlderThanSqlite335());
 }

moor/test/skips.dart

@@ -1,5 +1,5 @@
 import 'package:sqlite3/sqlite3.dart';
 
-String? onNoReturningSupport() => sqlite3.version.versionNumber > 3035000
+String? ifOlderThanSqlite335() => sqlite3.version.versionNumber > 3035000
     ? null
     : 'RETURNING not supported by sqlite version ${sqlite3.version.libVersion}';