Bugfix feature - String columns to support MAX and MIN

.gitignore

@@ -20,3 +20,4 @@ docs/**/*.g.dart
 */build/
 drift/extension/devtools/build
 **/pubspec_overrides.yaml
+**.history/

drift/lib/src/runtime/query_builder/expressions/aggregate.dart

@@ -30,6 +30,20 @@ extension BaseAggregate<DT extends Object> on Expression<DT> {
         filter: filter, distinct: distinct);
   }
 
+  /// Return the maximum of all non-null values in this group.
+  ///
+  /// If there are no non-null values in the group, returns null.
+  /// {@macro drift_aggregate_filter}
+  Expression<DT> max({Expression<bool>? filter}) =>
+      _AggregateExpression('MAX', [this], filter: filter);
+
+  /// Return the minimum of all non-null values in this group.
+  ///
+  /// If there are no non-null values in the group, returns null.
+  /// {@macro drift_aggregate_filter}
+  Expression<DT> min({Expression<bool>? filter}) =>
+      _AggregateExpression('MIN', [this], filter: filter);
+
   /// Returns the concatenation of all non-null values in the current group,
   /// joined by the [separator].
   ///

drift/test/database/expressions/aggregate_test.dart

@@ -5,6 +5,7 @@ import '../../test_utils/test_utils.dart';
 
 void main() {
   const foo = CustomExpression<int>('foo', precedence: Precedence.primary);
+  const s1 = CustomExpression<String>('s1', precedence: Precedence.primary);
 
   group('count', () {
     test('all', () {
@@ -49,10 +50,12 @@ void main() {
 
   test('max', () {
     expect(foo.max(), generates('MAX(foo)'));
+    expect(s1.max(), generates('MAX(s1)'));
   });
 
   test('min', () {
     expect(foo.min(), generates('MIN(foo)'));
+    expect(s1.min(), generates('MIN(s1)'));
   });
 
   test('sum', () {