diff --git a/packages/orm/angel_orm/lib/src/builder.dart b/packages/orm/angel_orm/lib/src/builder.dart
index bf7dfa96..82b93efd 100644
--- a/packages/orm/angel_orm/lib/src/builder.dart
+++ b/packages/orm/angel_orm/lib/src/builder.dart
@@ -141,9 +141,13 @@ class EnumSqlExpressionBuilder<T> extends SqlExpressionBuilder<T> {
       UnsupportedError('Enums do not support this operation.');
 
   @override
-  String? compile() {
-    if (_raw != null) return _raw;
-    if (_value == null) return null;
+  String compile() {
+    if (_raw != null) {
+      return _raw!;
+    }
+    if (_value == null) {
+      return '';
+    }
     return '$_op $_value';
   }
 
@@ -243,7 +247,7 @@ class StringSqlExpressionBuilder extends SqlExpressionBuilder<String> {
   void isBetween(String lower, String upper) {
     query.substitutionValues[lowerName] = lower;
     query.substitutionValues[upperName] = upper;
-    _raw = "BETWEEN @$lowerName AND @$upperName";
+    _raw = 'BETWEEN @$lowerName AND @$upperName';
     _hasValue = true;
   }
 
@@ -506,10 +510,10 @@ abstract class JsonSqlExpressionBuilder<T, K> extends SqlExpressionBuilder<T> {
   }
 
   @override
-  String? compile() {
+  String compile() {
     var s = _compile();
     if (!_properties.any((p) => p.hasValue)) return s;
-    s ??= '';
+    //s ??= '';
 
     for (var p in _properties) {
       if (p.hasValue) {
@@ -517,7 +521,7 @@ abstract class JsonSqlExpressionBuilder<T, K> extends SqlExpressionBuilder<T> {
 
         if (c != null) {
           _hasValue = true;
-          s ??= '';
+          //s ??= '';
 
           if (p.typed is! DateTimeSqlExpressionBuilder) {
             s += '${p.typed!.columnName} ';
@@ -531,10 +535,14 @@ abstract class JsonSqlExpressionBuilder<T, K> extends SqlExpressionBuilder<T> {
     return s;
   }
 
-  String? _compile() {
-    if (_raw != null) return _raw;
-    if (_value == null) return null;
-    return "::jsonb $_op @$substitution::jsonb";
+  String _compile() {
+    if (_raw != null) {
+      return _raw!;
+    }
+    if (_value == null) {
+      return '';
+    }
+    return '::jsonb $_op @$substitution::jsonb';
   }
 
   void contains(T value) {
diff --git a/packages/orm/angel_orm/lib/src/query.dart b/packages/orm/angel_orm/lib/src/query.dart
index 8855a573..f00c026a 100644
--- a/packages/orm/angel_orm/lib/src/query.dart
+++ b/packages/orm/angel_orm/lib/src/query.dart
@@ -9,7 +9,7 @@ import 'query_where.dart';
 import 'package:optional/optional.dart';
 
 /// A SQL `SELECT` query builder.
-abstract class Query<T, Where extends QueryWhere?> extends QueryBase<T> {
+abstract class Query<T, Where extends QueryWhere> extends QueryBase<T> {
   final List<JoinBuilder> _joins = [];
   final Map<String, int> _names = {};
   final List<OrderBy> _orderBy = [];
@@ -80,27 +80,27 @@ abstract class Query<T, Where extends QueryWhere?> extends QueryBase<T> {
   /// Determines whether this query can be compiled.
   ///
   /// Used to prevent ambiguities in joins.
-  bool canCompile(Set<String>? trampoline) => true;
+  bool canCompile(Set<String> trampoline) => true;
 
   /// Shorthand for calling [where].or with a [Where] clause.
   void andWhere(void Function(Where) f) {
     var w = newWhereClause();
     f(w);
-    where?.and(w);
+    where.and(w);
   }
 
   /// Shorthand for calling [where].or with a [Where] clause.
   void notWhere(void Function(Where) f) {
     var w = newWhereClause();
     f(w);
-    where?.not(w);
+    where.not(w);
   }
 
   /// Shorthand for calling [where].or with a [Where] clause.
   void orWhere(void Function(Where) f) {
     var w = newWhereClause();
     f(w);
-    where?.or(w);
+    where.or(w);
   }
 
   /// Limit the number of rows to return.
@@ -128,12 +128,12 @@ abstract class Query<T, Where extends QueryWhere?> extends QueryBase<T> {
     _crossJoin = tableName;
   }
 
-  String _joinAlias(Set<String>? trampoline) {
+  String _joinAlias(Set<String> trampoline) {
     var i = _joins.length;
 
     while (true) {
       var a = 'a$i';
-      if (trampoline!.add(a)) {
+      if (trampoline.add(a)) {
         return a;
       } else {
         i++;
@@ -310,8 +310,8 @@ abstract class Query<T, Where extends QueryWhere?> extends QueryBase<T> {
     }
 
     var whereClause =
-        where?.compile(tableName: includeTableName ? tableName : null);
-    if (whereClause?.isNotEmpty == true) {
+        where.compile(tableName: includeTableName ? tableName : null);
+    if (whereClause.isNotEmpty == true) {
       b.write(' WHERE $whereClause');
     }
     if (_groupBy != null) b.write(' GROUP BY $_groupBy');
@@ -357,7 +357,7 @@ abstract class Query<T, Where extends QueryWhere?> extends QueryBase<T> {
   Future<Optional<T>> insert(QueryExecutor executor) {
     var insertion = values.compileInsert(this, tableName);
 
-    if (insertion == null) {
+    if (insertion == '') {
       throw StateError('No values have been specified for update.');
     } else {
       // TODO: How to do this in a non-Postgres DB?
@@ -375,12 +375,12 @@ abstract class Query<T, Where extends QueryWhere?> extends QueryBase<T> {
     var updateSql = StringBuffer('UPDATE $tableName ');
     var valuesClause = values.compileForUpdate(this);
 
-    if (valuesClause == null) {
+    if (valuesClause == '') {
       throw StateError('No values have been specified for update.');
     } else {
       updateSql.write(' $valuesClause');
-      var whereClause = where?.compile();
-      if (whereClause?.isNotEmpty == true) {
+      var whereClause = where.compile();
+      if (whereClause.isNotEmpty == true) {
         updateSql.write(' WHERE $whereClause');
       }
       if (_limit != null) updateSql.write(' LIMIT $_limit');
diff --git a/packages/orm/angel_orm/lib/src/query_values.dart b/packages/orm/angel_orm/lib/src/query_values.dart
index 2fbbb05b..6f0de4e4 100644
--- a/packages/orm/angel_orm/lib/src/query_values.dart
+++ b/packages/orm/angel_orm/lib/src/query_values.dart
@@ -14,12 +14,13 @@ abstract class QueryValues {
     }
   }
 
-  String? compileInsert(Query query, String tableName) {
+  String compileInsert(Query query, String tableName) {
     var data = Map<String, dynamic>.from(toMap());
     var keys = data.keys.toList();
     keys.where((k) => !query.fields.contains(k)).forEach(data.remove);
-    if (data.isEmpty) return null;
-
+    if (data.isEmpty) {
+      return '';
+    }
     var fieldSet = data.keys.join(', ');
     var b = StringBuffer('INSERT INTO $tableName ($fieldSet) VALUES (');
     var i = 0;
@@ -37,9 +38,11 @@ abstract class QueryValues {
     return b.toString();
   }
 
-  String? compileForUpdate(Query query) {
+  String compileForUpdate(Query query) {
     var data = toMap();
-    if (data.isEmpty) return null;
+    if (data.isEmpty) {
+      return '';
+    }
     var b = StringBuffer('SET');
     var i = 0;
 
diff --git a/packages/orm/angel_orm/lib/src/query_where.dart b/packages/orm/angel_orm/lib/src/query_where.dart
index e83b5eaa..fdf5f05d 100644
--- a/packages/orm/angel_orm/lib/src/query_where.dart
+++ b/packages/orm/angel_orm/lib/src/query_where.dart
@@ -2,27 +2,27 @@ import 'builder.dart';
 
 /// Builds a SQL `WHERE` clause.
 abstract class QueryWhere {
-  final Set<QueryWhere?> _and = Set();
-  final Set<QueryWhere?> _not = Set();
-  final Set<QueryWhere?> _or = Set();
+  final Set<QueryWhere> _and = {};
+  final Set<QueryWhere> _not = {};
+  final Set<QueryWhere> _or = {};
 
   Iterable<SqlExpressionBuilder> get expressionBuilders;
 
-  void and(QueryWhere? other) {
+  void and(QueryWhere other) {
     _and.add(other);
   }
 
-  void not(QueryWhere? other) {
+  void not(QueryWhere other) {
     _not.add(other);
   }
 
-  void or(QueryWhere? other) {
+  void or(QueryWhere other) {
     _or.add(other);
   }
 
   String compile({String? tableName}) {
     var b = StringBuffer();
-    int i = 0;
+    var i = 0;
 
     for (var builder in expressionBuilders) {
       var key = builder.columnName;
@@ -40,17 +40,17 @@ abstract class QueryWhere {
     }
 
     for (var other in _and) {
-      var sql = other!.compile();
+      var sql = other.compile();
       if (sql.isNotEmpty) b.write(' AND ($sql)');
     }
 
     for (var other in _not) {
-      var sql = other!.compile();
+      var sql = other.compile();
       if (sql.isNotEmpty) b.write(' NOT ($sql)');
     }
 
     for (var other in _or) {
-      var sql = other!.compile();
+      var sql = other.compile();
       if (sql.isNotEmpty) b.write(' OR ($sql)');
     }
 
diff --git a/packages/orm/angel_orm_test/example/car_controller.dart b/packages/orm/angel_orm_test/example/car_controller.dart
index fe42f733..f88441f4 100644
--- a/packages/orm/angel_orm_test/example/car_controller.dart
+++ b/packages/orm/angel_orm_test/example/car_controller.dart
@@ -7,7 +7,7 @@ import 'package:angel_orm_test/src/models/car.dart';
 class CarController extends Controller {
   @Expose('/luxury')
   Future<List<Car?>> getLuxuryCars(QueryExecutor connection) {
-    var query = new CarQuery();
+    var query = CarQuery();
     query.where
       ?..familyFriendly.equals(false)
       ..createdAt.year.greaterThanOrEqualTo(2014)
diff --git a/packages/orm/angel_orm_test/lib/src/models/email_indexed.dart b/packages/orm/angel_orm_test/lib/src/models/email_indexed.dart
index 903541b7..4ca4d3e0 100644
--- a/packages/orm/angel_orm_test/lib/src/models/email_indexed.dart
+++ b/packages/orm/angel_orm_test/lib/src/models/email_indexed.dart
@@ -12,7 +12,7 @@ abstract class _Role {
   String? get role;
 
   @ManyToMany(_RoleUser)
-  List<_User?>? get users;
+  List<_User> get users;
 }
 
 @serializable
@@ -35,5 +35,5 @@ abstract class _User {
   String? get password;
 
   @ManyToMany(_RoleUser)
-  List<_Role?>? get roles;
+  List<_Role> get roles;
 }
diff --git a/packages/orm/angel_orm_test/lib/src/models/email_indexed.g.dart b/packages/orm/angel_orm_test/lib/src/models/email_indexed.g.dart
index af1ce54c..741e4d5c 100644
--- a/packages/orm/angel_orm_test/lib/src/models/email_indexed.g.dart
+++ b/packages/orm/angel_orm_test/lib/src/models/email_indexed.g.dart
@@ -59,7 +59,7 @@ class UserMigration extends Migration {
 // OrmGenerator
 // **************************************************************************
 
-class RoleQuery extends Query<Role?, RoleQueryWhere?> {
+class RoleQuery extends Query<Role, RoleQueryWhere> {
   RoleQuery({Query? parent, Set<String>? trampoline}) : super(parent: parent) {
     trampoline ??= Set();
     trampoline.add(tableName);
@@ -137,8 +137,7 @@ class RoleQuery extends Query<Role?, RoleQueryWhere?> {
           var l = out[idx];
           return out
             ..[idx] = l.copyWith(
-                users: List<_User?>.from(l.users ?? [])
-                  ..addAll(model!.users ?? []));
+                users: List<_User>.from(l.users)..addAll(model!.users));
         }
       });
     });
@@ -156,8 +155,7 @@ class RoleQuery extends Query<Role?, RoleQueryWhere?> {
           var l = out[idx]!;
           return out
             ..[idx] = l.copyWith(
-                users: List<_User?>.from(l.users ?? [])
-                  ..addAll(model!.users ?? []));
+                users: List<_User>.from(l.users)..addAll(model!.users));
         }
       });
     });
@@ -175,8 +173,7 @@ class RoleQuery extends Query<Role?, RoleQueryWhere?> {
           var l = out[idx];
           return out
             ..[idx] = l.copyWith(
-                users: List<_User?>.from(l.users ?? [])
-                  ..addAll(model!.users ?? []));
+                users: List<_User>.from(l.users)..addAll(model!.users));
         }
       });
     });
@@ -329,7 +326,7 @@ class RoleUserQueryValues extends MapQueryValues {
   }
 }
 
-class UserQuery extends Query<User?, UserQueryWhere?> {
+class UserQuery extends Query<User, UserQueryWhere> {
   UserQuery({Query? parent, Set<String>? trampoline}) : super(parent: parent) {
     trampoline ??= Set();
     trampoline.add(tableName);
@@ -345,7 +342,7 @@ class UserQuery extends Query<User?, UserQueryWhere?> {
   @override
   final UserQueryValues values = UserQueryValues();
 
-  UserQueryWhere? _where;
+  UserQueryWhere _where;
 
   @override
   get casts {
@@ -363,7 +360,7 @@ class UserQuery extends Query<User?, UserQueryWhere?> {
   }
 
   @override
-  UserQueryWhere? get where {
+  UserQueryWhere get where {
     return _where;
   }
 
@@ -401,17 +398,16 @@ class UserQuery extends Query<User?, UserQueryWhere?> {
   @override
   get(QueryExecutor executor) {
     return super.get(executor).then((result) {
-      return result.fold<List<User?>>([], (out, model) {
-        var idx = out.indexWhere((m) => m!.email == model!.email);
+      return result.fold<List<User>>([], (out, model) {
+        var idx = out.indexWhere((m) => m.email == model.email);
 
         if (idx == -1) {
           return out..add(model);
         } else {
-          var l = out[idx]!;
+          var l = out[idx];
           return out
             ..[idx] = l.copyWith(
-                roles: List<_Role?>.from(l.roles ?? [])
-                  ..addAll(model!.roles ?? []));
+                roles: List<_Role>.from(l.roles)..addAll(model.roles));
         }
       });
     });
@@ -421,16 +417,15 @@ class UserQuery extends Query<User?, UserQueryWhere?> {
   update(QueryExecutor executor) {
     return super.update(executor).then((result) {
       return result.fold<List<User>>([], (out, model) {
-        var idx = out.indexWhere((m) => m.email == model!.email);
+        var idx = out.indexWhere((m) => m.email == model.email);
 
         if (idx == -1) {
-          return out..add(model!);
+          return out..add(model);
         } else {
           var l = out[idx];
           return out
             ..[idx] = l.copyWith(
-                roles: List<_Role?>.from(l.roles ?? [])
-                  ..addAll(model!.roles ?? []));
+                roles: List<_Role>.from(l.roles)..addAll(model.roles));
         }
       });
     });
@@ -440,16 +435,15 @@ class UserQuery extends Query<User?, UserQueryWhere?> {
   delete(QueryExecutor executor) {
     return super.delete(executor).then((result) {
       return result.fold<List<User>>([], (out, model) {
-        var idx = out.indexWhere((m) => m.email == model!.email);
+        var idx = out.indexWhere((m) => m.email == model.email);
 
         if (idx == -1) {
-          return out..add(model!);
+          return out..add(model);
         } else {
           var l = out[idx];
           return out
             ..[idx] = l.copyWith(
-                roles: List<_Role?>.from(l.roles ?? [])
-                  ..addAll(model!.roles ?? []));
+                roles: List<_Role>.from(l.roles)..addAll(model.roles));
         }
       });
     });
@@ -508,16 +502,16 @@ class UserQueryValues extends MapQueryValues {
 
 @generatedSerializable
 class Role implements _Role {
-  const Role({this.role, this.users});
+  const Role({this.role, this.users = const []});
 
   @override
   final String? role;
 
   @override
-  final List<_User?>? users;
+  final List<_User> users;
 
-  Role copyWith({String? role, List<_User?>? users}) {
-    return Role(role: role ?? this.role, users: users ?? this.users);
+  Role copyWith({String? role, List<_User> users = const []}) {
+    return Role(role: role ?? this.role, users: users);
   }
 
   bool operator ==(other) {
@@ -537,7 +531,7 @@ class Role implements _Role {
     return "Role(role=$role, users=$users)";
   }
 
-  Map<String, dynamic>? toJson() {
+  Map<String, dynamic> toJson() {
     return RoleSerializer.toMap(this);
   }
 }
@@ -577,7 +571,7 @@ class RoleUser implements _RoleUser {
 
 @generatedSerializable
 class User implements _User {
-  const User({this.email, this.name, this.password, this.roles});
+  const User({this.email, this.name, this.password, this.roles = const []});
 
   @override
   final String? email;
@@ -589,15 +583,18 @@ class User implements _User {
   final String? password;
 
   @override
-  final List<_Role?>? roles;
+  final List<_Role> roles;
 
   User copyWith(
-      {String? email, String? name, String? password, List<_Role?>? roles}) {
+      {String? email,
+      String? name,
+      String? password,
+      List<_Role> roles = const []}) {
     return User(
         email: email ?? this.email,
         name: name ?? this.name,
         password: password ?? this.password,
-        roles: roles ?? this.roles);
+        roles: roles);
   }
 
   bool operator ==(other) {
@@ -605,7 +602,7 @@ class User implements _User {
         other.email == email &&
         other.name == name &&
         other.password == password &&
-        ListEquality<_Role?>(DefaultEquality<_Role>())
+        ListEquality<_Role>(DefaultEquality<_Role>())
             .equals(other.roles, roles);
   }
 
@@ -619,7 +616,7 @@ class User implements _User {
     return "User(email=$email, name=$name, password=$password, roles=$roles)";
   }
 
-  Map<String, dynamic>? toJson() {
+  Map<String, dynamic> toJson() {
     return UserSerializer.toMap(this);
   }
 }
@@ -657,16 +654,13 @@ class RoleSerializer extends Codec<Role, Map?> {
         users: map['users'] is Iterable
             ? List.unmodifiable(((map['users'] as Iterable).whereType<Map>())
                 .map(UserSerializer.fromMap))
-            : null);
+            : []);
   }
 
-  static Map<String, dynamic>? toMap(_Role? model) {
-    if (model == null) {
-      return null;
-    }
+  static Map<String, dynamic> toMap(_Role model) {
     return {
       'role': model.role,
-      'users': model.users?.map((m) => UserSerializer.toMap(m)).toList()
+      'users': model.users.map((m) => UserSerializer.toMap(m)).toList()
     };
   }
 }
@@ -714,8 +708,8 @@ class RoleUserSerializer extends Codec<RoleUser, Map> {
 
   static Map<String, dynamic> toMap(_RoleUser model) {
     return {
-      'role': RoleSerializer.toMap(model.role),
-      'user': UserSerializer.toMap(model.user)
+      'role': (model.role != null) ? RoleSerializer.toMap(model.role!) : '',
+      'user': (model.user != null) ? UserSerializer.toMap(model.user!) : ''
     };
   }
 }
@@ -759,18 +753,15 @@ class UserSerializer extends Codec<User, Map?> {
         roles: map['roles'] is Iterable
             ? List.unmodifiable(((map['roles'] as Iterable).whereType<Map>())
                 .map(RoleSerializer.fromMap))
-            : null);
+            : []);
   }
 
-  static Map<String, dynamic>? toMap(_User? model) {
-    if (model == null) {
-      return null;
-    }
+  static Map<String, dynamic> toMap(_User model) {
     return {
       'email': model.email,
       'name': model.name,
       'password': model.password,
-      'roles': model.roles?.map((m) => RoleSerializer.toMap(m)).toList()
+      'roles': model.roles.map((m) => RoleSerializer.toMap(m)).toList()
     };
   }
 }