Validate data integrity before inserts and updates

end_to_end_testing/lib/tables.g.dart

@@ -24,14 +24,21 @@ class User {
 }
 
 class _$UsersTable extends Users implements TableInfo<Users, User> {
-  final GeneratedDatabase db;
-  _$UsersTable(this.db);
+  final GeneratedDatabase _db;
+  _$UsersTable(this._db);
   @override
-  GeneratedIntColumn get id => GeneratedIntColumn('id', false);
+  GeneratedIntColumn get id =>
+      GeneratedIntColumn('id', false, hasAutoIncrement: true);
   @override
-  GeneratedTextColumn get userName => GeneratedTextColumn('name', false);
+  GeneratedTextColumn get userName => GeneratedTextColumn(
+        'name',
+        false,
+      );
   @override
-  GeneratedTextColumn get bio => GeneratedTextColumn('bio', false);
+  GeneratedTextColumn get bio => GeneratedTextColumn(
+        'bio',
+        false,
+      );
   @override
   List<GeneratedColumn> get $columns => [id, userName, bio];
   @override
@@ -39,13 +46,16 @@ class _$UsersTable extends Users implements TableInfo<Users, User> {
   @override
   String get $tableName => 'users';
   @override
-  void validateIntegrity(User instance, bool isInserting) => null;
+  void validateIntegrity(User instance, bool isInserting) =>
+      id.isAcceptableValue(instance.id, isInserting) &&
+      userName.isAcceptableValue(instance.userName, isInserting) &&
+      bio.isAcceptableValue(instance.bio, isInserting);
   @override
   Set<GeneratedColumn> get $primaryKey => Set();
   @override
   User map(Map<String, dynamic> data) {
-    final intType = db.typeSystem.forDartType<int>();
-    final stringType = db.typeSystem.forDartType<String>();
+    final intType = _db.typeSystem.forDartType<int>();
+    final stringType = _db.typeSystem.forDartType<String>();
     return User(
       id: intType.mapFromDatabaseResponse(data['id']),
       userName: stringType.mapFromDatabaseResponse(data['name']),

sally/README.md

@@ -80,7 +80,7 @@ class MyDatabase extends _$MyDatabase {
   MigrationStrategy get migration => MigrationStrategy();
 }
 ```
-You can ignore these two getters there at the moment, the imporant part is that you can
+You can ignore these two getters there at the moment, the important part is that you can
 now run your queries with fluent Dart code:
 ```dart
 class MyDatabase extends _$MyDatabase {
@@ -114,6 +114,7 @@ supporting floating / fixed point numbers as well would be awesome
   - DSL API
   - Support in generator
   - Use in queries (`IS NOT NULL`)
+  - Setting fields to null during updates
 - Verify constraints (text length, nullability, etc.) before inserting or
   deleting data.
 - Support Dart VM apps

sally/lib/src/runtime/structure/columns.dart

@@ -39,6 +39,17 @@ abstract class GeneratedColumn<T, S extends SqlType<T>> extends Column<T, S> {
 
   @override
   Expression<BoolType> equals(T compare) => equalsExp(Variable<T, S>(compare));
+
+  /// Checks whether the given value fits into this column. The default
+  /// implementation checks whether the value is not null, as null values are
+  /// only allowed for updates or if the column is nullable.
+  /// If [duringInsert] is true, the method should check whether the value is
+  /// suitable for a new row that is being inserted. If it's false, we the
+  /// method should check whether the value is valid for an update. Null values
+  /// should always be accepted for updates, as the describe a value that should
+  /// not be replaced.
+  bool isAcceptableValue(T value, bool duringInsert) =>
+      ($nullable || !duringInsert) || value != null;
 }
 
 class GeneratedTextColumn extends GeneratedColumn<String, StringType>
@@ -91,4 +102,8 @@ class GeneratedIntColumn extends GeneratedColumn<int, IntType>
   @override
   Expression<BoolType> isSmallerThan(int i) =>
       Comparison(this, ComparisonOperator.less, Variable<int, IntType>(i));
+
+  @override
+  bool isAcceptableValue(int value, bool duringInsert) =>
+      hasAutoIncrement || super.isAcceptableValue(value, duringInsert);
 }

sally_generator/lib/src/writer/table_writer.dart

@@ -1,4 +1,5 @@
 import 'package:recase/recase.dart';
+import 'package:sally_generator/src/model/specified_column.dart';
 import 'package:sally_generator/src/model/specified_table.dart';
 import 'package:sally_generator/src/writer/data_class_writer.dart';
 
@@ -25,19 +26,12 @@ class TableWriter {
       ..write('class ${table.tableInfoName} extends $tableDslName '
           'implements TableInfo<$tableDslName, $dataClass> {\n')
       // should have a GeneratedDatabase reference that is set in the constructor
-      ..write('final GeneratedDatabase db;\n')
-      ..write('${table.tableInfoName}(this.db);\n');
+      ..write('final GeneratedDatabase _db;\n')
+      ..write('${table.tableInfoName}(this._db);\n');
 
     // Generate the columns
     for (var column in table.columns) {
-      final isNullable = false;
-
-      // @override
-      // GeneratedIntColumn get id => GeneratedIntColumn('sql_name', isNullable);
-      buffer
-        ..write('@override \n')
-        ..write('${column.implColumnTypeName} get ${column.dartGetterName} => '
-            '${column.implColumnTypeName}(\'${column.name.name}\', $isNullable);\n');
+      _writeColumnGetter(buffer, column);
     }
 
     // Generate $columns, $tableName, asDslTable getters
@@ -48,9 +42,9 @@ class TableWriter {
       ..write(
           '@override\nList<GeneratedColumn> get \$columns => [$columnsWithGetters];\n')
       ..write('@override\n$tableDslName get asDslTable => this;\n')
-      ..write('@override\nString get \$tableName => \'${table.sqlName}\';\n')
-      ..write(
-          '@override\nvoid validateIntegrity($dataClass instance, bool isInserting) => null;');
+      ..write('@override\nString get \$tableName => \'${table.sqlName}\';\n');
+
+    _writeValidityCheckMethod(buffer);
 
     // todo replace set syntax with literal once dart supports it
     // write primary key getter: Set<Column> get $primaryKey => Set().add(id);
@@ -83,7 +77,7 @@ class TableWriter {
       dartTypeToResolver[usedType] = resolver;
 
       buffer
-          .write('final $resolver = db.typeSystem.forDartType<$usedType>();\n');
+          .write('final $resolver = _db.typeSystem.forDartType<$usedType>();\n');
     }
 
     // finally, the mighty constructor invocation:
@@ -119,4 +113,50 @@ class TableWriter {
 
     buffer.write('return map; \n}\n');
   }
+
+  void _writeColumnGetter(StringBuffer buffer, SpecifiedColumn column) {
+    final isNullable = false; // todo nullability for columns
+    final additionalParams = <String, String>{};
+
+    if (column.hasAI) {
+      additionalParams['hasAutoIncrement'] = 'true';
+    }
+
+    // @override
+    // GeneratedIntColumn get id => GeneratedIntColumn('sql_name', isNullable);
+    buffer
+      ..write('@override \n')
+      ..write('${column.implColumnTypeName} get ${column.dartGetterName} => '
+          '${column.implColumnTypeName}(\'${column.name.name}\', $isNullable, ');
+
+    var first = true;
+    additionalParams.forEach((name, value) {
+      if (!first) {
+        buffer.write(', ');
+      } else {
+        first = false;
+      }
+
+      buffer..write(name)..write(': ')..write(value);
+    });
+
+    buffer.write(');\n');
+  }
+
+  void _writeValidityCheckMethod(StringBuffer buffer) {
+    final dataClass = table.dartTypeName;
+
+    buffer.write('@override\nvoid validateIntegrity($dataClass instance, bool isInserting) => ');
+
+    final validationCode = table.columns.map((column) {
+      final getterName = column.dartGetterName;
+
+      // generated columns have a isAcceptableValue(T value, bool duringInsert)
+      // method
+
+      return '$getterName.isAcceptableValue(instance.$getterName, isInserting)';
+    }).join('&&');
+
+    buffer..write(validationCode)..write(';\n');
+  }
 }