diff --git a/angel_orm/example/main.angel_serialize.g.part b/angel_orm/example/main.angel_serialize.g.part
new file mode 100644
index 00000000..708a0a9d
--- /dev/null
+++ b/angel_orm/example/main.angel_serialize.g.part
@@ -0,0 +1,67 @@
+// **************************************************************************
+// JsonModelGenerator
+// **************************************************************************
+
+@generatedSerializable
+class Employee extends _Employee {
+  Employee(
+      {this.id,
+      this.firstName,
+      this.lastName,
+      this.salary,
+      this.createdAt,
+      this.updatedAt});
+
+  @override
+  final String id;
+
+  @override
+  final String firstName;
+
+  @override
+  final String lastName;
+
+  @override
+  final double salary;
+
+  @override
+  final DateTime createdAt;
+
+  @override
+  final DateTime updatedAt;
+
+  Employee copyWith(
+      {String id,
+      String firstName,
+      String lastName,
+      double salary,
+      DateTime createdAt,
+      DateTime updatedAt}) {
+    return new Employee(
+        id: id ?? this.id,
+        firstName: firstName ?? this.firstName,
+        lastName: lastName ?? this.lastName,
+        salary: salary ?? this.salary,
+        createdAt: createdAt ?? this.createdAt,
+        updatedAt: updatedAt ?? this.updatedAt);
+  }
+
+  bool operator ==(other) {
+    return other is _Employee &&
+        other.id == id &&
+        other.firstName == firstName &&
+        other.lastName == lastName &&
+        other.salary == salary &&
+        other.createdAt == createdAt &&
+        other.updatedAt == updatedAt;
+  }
+
+  @override
+  int get hashCode {
+    return hashObjects([id, firstName, lastName, salary, createdAt, updatedAt]);
+  }
+
+  Map<String, dynamic> toJson() {
+    return EmployeeSerializer.toMap(this);
+  }
+}
diff --git a/angel_orm/example/main.dart b/angel_orm/example/main.dart
index 21f34ffc..75f76a0f 100644
--- a/angel_orm/example/main.dart
+++ b/angel_orm/example/main.dart
@@ -1,27 +1,92 @@
 import 'package:angel_model/angel_model.dart';
 import 'package:angel_orm/angel_orm.dart';
+import 'package:angel_serialize/angel_serialize.dart';
+part 'main.g.dart';
+part 'main.serializer.g.dart';
 
-main() {
+main() async {
+  var query = new EmployeeQuery();
+  query.where
+    ..firstName.equals('Rich')
+    ..lastName.equals('Person')
+    ..or(new EmployeeQueryWhere()..salary.greaterThanOrEqualTo(75000));
 
+  var richPerson = await query.getOne(new _FakeExecutor());
+  print(richPerson.toJson());
 }
 
-@postgreSqlOrm
-abstract class Company extends Model {
-  String get name;
+class _FakeExecutor extends QueryExecutor {
+  const _FakeExecutor();
 
-  bool get isFortune500;
+  @override
+  Future<List<List>> query(String query) async {
+    var now = new DateTime.now();
+    print('_FakeExecutor received query: $query');
+    return [
+      [1, 'Rich', 'Person', 100000.0, now, now]
+    ];
+  }
 }
 
-@postgreSqlOrm
+@orm
+@serializable
 abstract class _Employee extends Model {
-  @belongsTo
-  Company get company;
-
   String get firstName;
 
   String get lastName;
 
   double get salary;
-
-  bool get isFortune500Employee => company.isFortune500;
+}
+
+class EmployeeQuery extends Query<Employee, EmployeeQueryWhere> {
+  @override
+  final EmployeeQueryWhere where = new EmployeeQueryWhere();
+
+  @override
+  String get tableName => 'employees';
+
+  @override
+  List<String> get fields =>
+      ['id', 'first_name', 'last_name', 'salary', 'created_at', 'updated_at'];
+
+  @override
+  Employee deserialize(List row) {
+    return new Employee(
+        id: row[0].toString(),
+        firstName: row[1] as String,
+        lastName: row[2] as String,
+        salary: row[3] as double,
+        createdAt: row[4] as DateTime,
+        updatedAt: row[5] as DateTime);
+  }
+}
+
+class EmployeeQueryWhere extends QueryWhere {
+  @override
+  Map<String, SqlExpressionBuilder> get expressionBuilders {
+    return {
+      'id': id,
+      'first_name': firstName,
+      'last_name': lastName,
+      'salary': salary,
+      'created_at': createdAt,
+      'updated_at': updatedAt
+    };
+  }
+
+  final NumericSqlExpressionBuilder<int> id =
+      new NumericSqlExpressionBuilder<int>();
+
+  final StringSqlExpressionBuilder firstName = new StringSqlExpressionBuilder();
+
+  final StringSqlExpressionBuilder lastName = new StringSqlExpressionBuilder();
+
+  final NumericSqlExpressionBuilder<double> salary =
+      new NumericSqlExpressionBuilder<double>();
+
+  final DateTimeSqlExpressionBuilder createdAt =
+      new DateTimeSqlExpressionBuilder('created_at');
+
+  final DateTimeSqlExpressionBuilder updatedAt =
+      new DateTimeSqlExpressionBuilder('updated_at');
 }
diff --git a/angel_orm/example/main.g.dart b/angel_orm/example/main.g.dart
new file mode 100644
index 00000000..950cbd12
--- /dev/null
+++ b/angel_orm/example/main.g.dart
@@ -0,0 +1,71 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'main.dart';
+
+// **************************************************************************
+// JsonModelGenerator
+// **************************************************************************
+
+@generatedSerializable
+class Employee extends _Employee {
+  Employee(
+      {this.id,
+      this.firstName,
+      this.lastName,
+      this.salary,
+      this.createdAt,
+      this.updatedAt});
+
+  @override
+  final String id;
+
+  @override
+  final String firstName;
+
+  @override
+  final String lastName;
+
+  @override
+  final double salary;
+
+  @override
+  final DateTime createdAt;
+
+  @override
+  final DateTime updatedAt;
+
+  Employee copyWith(
+      {String id,
+      String firstName,
+      String lastName,
+      double salary,
+      DateTime createdAt,
+      DateTime updatedAt}) {
+    return new Employee(
+        id: id ?? this.id,
+        firstName: firstName ?? this.firstName,
+        lastName: lastName ?? this.lastName,
+        salary: salary ?? this.salary,
+        createdAt: createdAt ?? this.createdAt,
+        updatedAt: updatedAt ?? this.updatedAt);
+  }
+
+  bool operator ==(other) {
+    return other is _Employee &&
+        other.id == id &&
+        other.firstName == firstName &&
+        other.lastName == lastName &&
+        other.salary == salary &&
+        other.createdAt == createdAt &&
+        other.updatedAt == updatedAt;
+  }
+
+  @override
+  int get hashCode {
+    return hashObjects([id, firstName, lastName, salary, createdAt, updatedAt]);
+  }
+
+  Map<String, dynamic> toJson() {
+    return EmployeeSerializer.toMap(this);
+  }
+}
diff --git a/angel_orm/example/main.serializer.g.dart b/angel_orm/example/main.serializer.g.dart
new file mode 100644
index 00000000..5e160b3b
--- /dev/null
+++ b/angel_orm/example/main.serializer.g.dart
@@ -0,0 +1,64 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'main.dart';
+
+// **************************************************************************
+// SerializerGenerator
+// **************************************************************************
+
+abstract class EmployeeSerializer {
+  static Employee fromMap(Map map) {
+    return new Employee(
+        id: map['id'] as String,
+        firstName: map['first_name'] as String,
+        lastName: map['last_name'] as String,
+        salary: map['salary'] as double,
+        createdAt: map['created_at'] != null
+            ? (map['created_at'] is DateTime
+                ? (map['created_at'] as DateTime)
+                : DateTime.parse(map['created_at'].toString()))
+            : null,
+        updatedAt: map['updated_at'] != null
+            ? (map['updated_at'] is DateTime
+                ? (map['updated_at'] as DateTime)
+                : DateTime.parse(map['updated_at'].toString()))
+            : null);
+  }
+
+  static Map<String, dynamic> toMap(Employee model) {
+    if (model == null) {
+      return null;
+    }
+    return {
+      'id': model.id,
+      'first_name': model.firstName,
+      'last_name': model.lastName,
+      'salary': model.salary,
+      'created_at': model.createdAt?.toIso8601String(),
+      'updated_at': model.updatedAt?.toIso8601String()
+    };
+  }
+}
+
+abstract class EmployeeFields {
+  static const List<String> allFields = const <String>[
+    id,
+    firstName,
+    lastName,
+    salary,
+    createdAt,
+    updatedAt
+  ];
+
+  static const String id = 'id';
+
+  static const String firstName = 'first_name';
+
+  static const String lastName = 'last_name';
+
+  static const String salary = 'salary';
+
+  static const String createdAt = 'created_at';
+
+  static const String updatedAt = 'updated_at';
+}
diff --git a/angel_orm/lib/angel_orm.dart b/angel_orm/lib/angel_orm.dart
index 1af57ece..3ba225e9 100644
--- a/angel_orm/lib/angel_orm.dart
+++ b/angel_orm/lib/angel_orm.dart
@@ -1,4 +1,5 @@
 export 'src/annotations.dart';
+export 'src/builder.dart';
 export 'src/migration.dart';
 export 'src/relations.dart';
 export 'src/query.dart';
\ No newline at end of file
diff --git a/angel_orm/lib/src/annotations.dart b/angel_orm/lib/src/annotations.dart
index c5ac0266..5d784e07 100644
--- a/angel_orm/lib/src/annotations.dart
+++ b/angel_orm/lib/src/annotations.dart
@@ -1,23 +1,9 @@
-const Orm mongoDBOrm = const Orm(OrmType.mongoDB);
-
-const Orm rethinkDBOrm = const Orm(OrmType.rethinkDB);
-
-const Orm postgreSqlOrm = const Orm(OrmType.postgreSql);
-
-const Orm mySqlOrm = const Orm(OrmType.mySql);
+const Orm orm = const Orm();
 
 class Orm {
-  final OrmType type;
   final String tableName;
 
-  const Orm(this.type, {this.tableName});
-}
-
-enum OrmType {
-  mongoDB,
-  rethinkDB,
-  mySql,
-  postgreSql,
+  const Orm({this.tableName});
 }
 
 class CanJoin {
diff --git a/angel_orm/lib/src/builder.dart b/angel_orm/lib/src/builder.dart
new file mode 100644
index 00000000..6fbe6547
--- /dev/null
+++ b/angel_orm/lib/src/builder.dart
@@ -0,0 +1,340 @@
+import 'package:intl/intl.dart' show DateFormat;
+import 'package:string_scanner/string_scanner.dart';
+
+final DateFormat dateYmd = new DateFormat('yyyy-MM-dd');
+final DateFormat dateYmdHms = new DateFormat('yyyy-MM-dd HH:mm:ss');
+
+/// Cleans an input SQL expression of common SQL injection points.
+String sanitizeExpression(String unsafe) {
+  var buf = new StringBuffer();
+  var scanner = new StringScanner(unsafe);
+  int ch;
+
+  while (!scanner.isDone) {
+    // Ignore comment starts
+    if (scanner.scan('--') || scanner.scan('/*'))
+      continue;
+
+    // Ignore all single quotes and attempted escape sequences
+    else if (scanner.scan("'") || scanner.scan('\\'))
+      continue;
+
+    // Otherwise, add the next char, unless it's a null byte.
+    else if ((ch = scanner.readChar()) != 0 && ch != null)
+      buf.writeCharCode(ch);
+  }
+
+  return buf.toString();
+}
+
+abstract class SqlExpressionBuilder<T> {
+  bool get hasValue;
+
+  String compile();
+
+  void isBetween(T lower, T upper);
+
+  void isNotBetween(T lower, T upper);
+
+  void isIn(Iterable<T> values);
+
+  void isNotIn(Iterable<T> values);
+}
+
+class NumericSqlExpressionBuilder<T extends num>
+    implements SqlExpressionBuilder<T> {
+  bool _hasValue = false;
+  String _op = '=';
+  String _raw;
+  T _value;
+
+  @override
+  bool get hasValue => _hasValue;
+
+  bool _change(String op, T value) {
+    _raw = null;
+    _op = op;
+    _value = value;
+    return _hasValue = true;
+  }
+
+  @override
+  String compile() {
+    if (_raw != null) return _raw;
+    if (_value == null) return null;
+    return '$_op $_value';
+  }
+
+  operator <(T value) => _change('<', value);
+
+  operator >(T value) => _change('>', value);
+
+  operator <=(T value) => _change('<=', value);
+
+  operator >=(T value) => _change('>=', value);
+
+  void lessThan(T value) {
+    _change('<', value);
+  }
+
+  void lessThanOrEqualTo(T value) {
+    _change('<=', value);
+  }
+
+  void greaterThan(T value) {
+    _change('>', value);
+  }
+
+  void greaterThanOrEqualTo(T value) {
+    _change('>=', value);
+  }
+
+  void equals(T value) {
+    _change('=', value);
+  }
+
+  void notEquals(T value) {
+    _change('!=', value);
+  }
+
+  @override
+  void isBetween(T lower, T upper) {
+    _raw = 'BETWEEN $lower AND $upper';
+    _hasValue = true;
+  }
+
+  @override
+  void isNotBetween(T lower, T upper) {
+    _raw = 'NOT BETWEEN $lower AND $upper';
+    _hasValue = true;
+  }
+
+  @override
+  void isIn(Iterable<T> values) {
+    _raw = 'IN (' + values.join(', ') + ')';
+    _hasValue = true;
+  }
+
+  @override
+  void isNotIn(Iterable<T> values) {
+    _raw = 'NOT IN (' + values.join(', ') + ')';
+    _hasValue = true;
+  }
+}
+
+class StringSqlExpressionBuilder implements SqlExpressionBuilder<String> {
+  bool _hasValue = false;
+  String _op = '=', _raw, _value;
+
+  @override
+  bool get hasValue => _hasValue;
+
+  bool _change(String op, String value) {
+    _raw = null;
+    _op = op;
+    _value = value;
+    return _hasValue = true;
+  }
+
+  @override
+  String compile() {
+    if (_raw != null) return _raw;
+    if (_value == null) return null;
+    var v = sanitizeExpression(_value);
+    return "$_op '$v'";
+  }
+
+  void isEmpty() => equals('');
+
+  void equals(String value) {
+    _change('=', value);
+  }
+
+  void notEquals(String value) {
+    _change('!=', value);
+  }
+
+  void like(String value) {
+    _change('LIKE', value);
+  }
+
+  @override
+  void isBetween(String lower, String upper) {
+    var l = sanitizeExpression(lower), u = sanitizeExpression(upper);
+    _raw = "BETWEEN '$l' AND '$u'";
+    _hasValue = true;
+  }
+
+  @override
+  void isNotBetween(String lower, String upper) {
+    var l = sanitizeExpression(lower), u = sanitizeExpression(upper);
+    _raw = "NOT BETWEEN '$l' AND '$u'";
+    _hasValue = true;
+  }
+
+  @override
+  void isIn(Iterable<String> values) {
+    _raw = 'IN (' +
+        values.map(sanitizeExpression).map((s) => "'$s'").join(', ') +
+        ')';
+    _hasValue = true;
+  }
+
+  @override
+  void isNotIn(Iterable<String> values) {
+    _raw = 'NOT IN (' +
+        values.map(sanitizeExpression).map((s) => "'$s'").join(', ') +
+        ')';
+    _hasValue = true;
+  }
+}
+
+class BooleanSqlExpressionBuilder implements SqlExpressionBuilder<bool> {
+  bool _hasValue = false;
+  String _op = '=', _raw;
+  bool _value;
+
+  @override
+  bool get hasValue => _hasValue;
+
+  bool _change(String op, bool value) {
+    _raw = null;
+    _op = op;
+    _value = value;
+    return _hasValue = true;
+  }
+
+  @override
+  String compile() {
+    if (_raw != null) return _raw;
+    if (_value == null) return null;
+    var v = _value ? 'TRUE' : 'FALSE';
+    return '$_op $v';
+  }
+
+  void equals(bool value) {
+    _change('=', value);
+  }
+
+  void notEquals(bool value) {
+    _change('!=', value);
+  }
+
+  @override
+  void isBetween(bool lower, bool upper) => throw new UnsupportedError(
+      'Booleans do not support BETWEEN expressions.');
+
+  @override
+  void isNotBetween(bool lower, bool upper) => isBetween(lower, upper);
+
+  @override
+  void isIn(Iterable<bool> values) {
+    _raw = 'IN (' + values.map((b) => b ? 'TRUE' : 'FALSE').join(', ') + ')';
+    _hasValue = true;
+  }
+
+  @override
+  void isNotIn(Iterable<bool> values) {
+    _raw =
+        'NOT IN (' + values.map((b) => b ? 'TRUE' : 'FALSE').join(', ') + ')';
+    _hasValue = true;
+  }
+}
+
+class DateTimeSqlExpressionBuilder implements SqlExpressionBuilder<DateTime> {
+  final NumericSqlExpressionBuilder<int> year =
+          new NumericSqlExpressionBuilder<int>(),
+      month = new NumericSqlExpressionBuilder<int>(),
+      day = new NumericSqlExpressionBuilder<int>(),
+      hour = new NumericSqlExpressionBuilder<int>(),
+      minute = new NumericSqlExpressionBuilder<int>(),
+      second = new NumericSqlExpressionBuilder<int>();
+  final String columnName;
+  String _raw;
+
+  DateTimeSqlExpressionBuilder(this.columnName);
+
+  @override
+  bool get hasValue =>
+      _raw?.isNotEmpty == true ||
+      year.hasValue ||
+      month.hasValue ||
+      day.hasValue ||
+      hour.hasValue ||
+      minute.hasValue ||
+      second.hasValue;
+
+  bool _change(String _op, DateTime dt, bool time) {
+    var dateString = time ? dateYmdHms.format(dt) : dateYmd.format(dt);
+    _raw = '$columnName $_op \'$dateString\'';
+    return true;
+  }
+
+  operator <(DateTime value) => _change('<', value, true);
+
+  operator <=(DateTime value) => _change('<=', value, true);
+
+  operator >(DateTime value) => _change('>', value, true);
+
+  operator >=(DateTime value) => _change('>=', value, true);
+
+  void equals(DateTime value, {bool includeTime: true}) {
+    _change('=', value, includeTime != false);
+  }
+
+  void lessThan(DateTime value, {bool includeTime: true}) {
+    _change('<', value, includeTime != false);
+  }
+
+  void lessThanOrEqualTo(DateTime value, {bool includeTime: true}) {
+    _change('<=', value, includeTime != false);
+  }
+
+  void greaterThan(DateTime value, {bool includeTime: true}) {
+    _change('>', value, includeTime != false);
+  }
+
+  void greaterThanOrEqualTo(DateTime value, {bool includeTime: true}) {
+    _change('>=', value, includeTime != false);
+  }
+
+  @override
+  void isIn(Iterable<DateTime> values) {
+    _raw = '$columnName IN (' +
+        values.map(dateYmdHms.format).map((s) => '$s').join(', ') +
+        ')';
+  }
+
+  @override
+  void isNotIn(Iterable<DateTime> values) {
+    _raw = '$columnName NOT IN (' +
+        values.map(dateYmdHms.format).map((s) => '$s').join(', ') +
+        ')';
+  }
+
+  @override
+  void isBetween(DateTime lower, DateTime upper) {
+    var l = dateYmdHms.format(lower), u = dateYmdHms.format(upper);
+    _raw = "$columnName BETWEEN '$l' and '$u'";
+  }
+
+  @override
+  void isNotBetween(DateTime lower, DateTime upper) {
+    var l = dateYmdHms.format(lower), u = dateYmdHms.format(upper);
+    _raw = "$columnName NOT BETWEEN '$l' and '$u'";
+  }
+
+  @override
+  String compile() {
+    if (_raw?.isNotEmpty == true) return _raw;
+    List<String> parts = [];
+    if (year.hasValue) parts.add('YEAR($columnName) ${year.compile()}');
+    if (month.hasValue) parts.add('MONTH($columnName) ${month.compile()}');
+    if (day.hasValue) parts.add('DAY($columnName) ${day.compile()}');
+    if (hour.hasValue) parts.add('HOUR($columnName) ${hour.compile()}');
+    if (minute.hasValue) parts.add('MINUTE($columnName) ${minute.compile()}');
+    if (second.hasValue) parts.add('SECOND($columnName) ${second.compile()}');
+
+    return parts.isEmpty ? null : parts.join(' AND ');
+  }
+}
diff --git a/angel_orm/lib/src/query.dart b/angel_orm/lib/src/query.dart
index 406222fc..cfb23413 100644
--- a/angel_orm/lib/src/query.dart
+++ b/angel_orm/lib/src/query.dart
@@ -1,340 +1,122 @@
-import 'package:intl/intl.dart';
-import 'package:string_scanner/string_scanner.dart';
-
-final DateFormat dateYmd = new DateFormat('yyyy-MM-dd');
-final DateFormat dateYmdHms = new DateFormat('yyyy-MM-dd HH:mm:ss');
-
-/// Cleans an input SQL expression of common SQL injection points.
-String sanitizeExpression(String unsafe) {
-  var buf = new StringBuffer();
-  var scanner = new StringScanner(unsafe);
-  int ch;
-
-  while (!scanner.isDone) {
-    // Ignore comment starts
-    if (scanner.scan('--') || scanner.scan('/*'))
-      continue;
-
-    // Ignore all single quotes and attempted escape sequences
-    else if (scanner.scan("'") || scanner.scan('\\'))
-      continue;
-
-    // Otherwise, add the next char, unless it's a null byte.
-    else if ((ch = scanner.readChar()) != 0 && ch != null)
-      buf.writeCharCode(ch);
-  }
-
-  return buf.toString();
-}
-
-abstract class SqlExpressionBuilder<T> {
-  bool get hasValue;
+import 'dart:async';
+import 'builder.dart';
 
+/// A base class for objects that compile to SQL queries, typically within an ORM.
+abstract class QueryBase<T> {
   String compile();
 
-  void isBetween(T lower, T upper);
+  T deserialize(List row);
 
-  void isNotBetween(T lower, T upper);
+  Future<List<T>> get(QueryExecutor executor) async {
+    var sql = compile();
+    return executor.query(sql).then((it) => it.map(deserialize).toList());
+  }
 
-  void isIn(Iterable<T> values);
+  Future<T> getOne(QueryExecutor executor) {
+    return get(executor).then((it) => it.isEmpty ? null : it.first);
+  }
 
-  void isNotIn(Iterable<T> values);
+  Union<T> union(QueryBase<T> other) {
+    return new Union(this, other);
+  }
+
+  Union<T> unionAll(QueryBase<T> other) {
+    return new Union(this, other, all: true);
+  }
 }
 
-class NumericSqlExpressionBuilder<T extends num>
-    implements SqlExpressionBuilder<T> {
-  bool _hasValue = false;
-  String _op = '=';
-  String _raw;
-  T _value;
+/// A SQL `SELECT` query builder.
+abstract class Query<T, Where extends QueryWhere> extends QueryBase<T> {
+  /// The table against which to execute this query.
+  String get tableName;
 
-  @override
-  bool get hasValue => _hasValue;
+  /// The list of fields returned by this query.
+  ///
+  /// If it's `null`, then this query will perform a `SELECT *`.
+  List<String> get fields;
 
-  bool _change(String op, T value) {
-    _raw = null;
-    _op = op;
-    _value = value;
-    return _hasValue = true;
-  }
+  /// A reference to an abstract query builder.
+  ///
+  /// This is often a generated class.
+  Where get where;
 
   @override
   String compile() {
-    if (_raw != null) return _raw;
-    if (_value == null) return null;
-    return '$_op $_value';
-  }
-
-  operator <(T value) => _change('<', value);
-
-  operator >(T value) => _change('>', value);
-
-  operator <=(T value) => _change('<=', value);
-
-  operator >=(T value) => _change('>=', value);
-
-  void lessThan(T value) {
-    _change('<', value);
-  }
-
-  void lessThanOrEqualTo(T value) {
-    _change('<=', value);
-  }
-
-  void greaterThan(T value) {
-    _change('>', value);
-  }
-
-  void greaterThanOrEqualTo(T value) {
-    _change('>=', value);
-  }
-
-  void equals(T value) {
-    _change('=', value);
-  }
-
-  void notEquals(T value) {
-    _change('!=', value);
-  }
-
-  @override
-  void isBetween(T lower, T upper) {
-    _raw = 'BETWEEN $lower AND $upper';
-    _hasValue = true;
-  }
-
-  @override
-  void isNotBetween(T lower, T upper) {
-    _raw = 'NOT BETWEEN $lower AND $upper';
-    _hasValue = true;
-  }
-
-  @override
-  void isIn(Iterable<T> values) {
-    _raw = 'IN (' + values.join(', ') + ')';
-    _hasValue = true;
-  }
-
-  @override
-  void isNotIn(Iterable<T> values) {
-    _raw = 'NOT IN (' + values.join(', ') + ')';
-    _hasValue = true;
+    var b = new StringBuffer('SELECT ');
+    if (fields == null)
+      b.write('*');
+    else
+      b.write(fields.join(', '));
+    b.write(' FROM $tableName');
+    var whereClause = where.compile();
+    if (whereClause.isNotEmpty) b.write(' WHERE $whereClause');
+    return b.toString();
   }
 }
 
-class StringSqlExpressionBuilder implements SqlExpressionBuilder<String> {
-  bool _hasValue = false;
-  String _op = '=', _raw, _value;
+/// Builds a SQL `WHERE` clause.
+abstract class QueryWhere {
+  final Set<QueryWhere> _and = new Set();
+  final Set<QueryWhere> _or = new Set();
+
+  Map<String, SqlExpressionBuilder> get expressionBuilders;
+
+  void and(QueryWhere other) {
+    _and.add(other);
+  }
+
+  void or(QueryWhere other) {
+    _or.add(other);
+  }
+
+  String compile() {
+    var b = new StringBuffer();
+    int i = 0;
+
+    for (var entry in expressionBuilders.entries) {
+      var key = entry.key, builder = entry.value;
+      if (builder.hasValue) {
+        if (i++ > 0) b.write(' AND ');
+        b.write('$key ${builder.compile()}');
+      }
+    }
+
+    for (var other in _and) {
+      var sql = other.compile();
+      if (sql.isNotEmpty) b.write(' AND $sql');
+    }
+
+    for (var other in _or) {
+      var sql = other.compile();
+      if (sql.isNotEmpty) b.write(' OR $sql');
+    }
+
+    return b.toString();
+  }
+}
+
+/// Represents the `UNION` of two subqueries.
+class Union<T> extends QueryBase<T> {
+  final QueryBase<T> left, right;
+  final bool all;
+
+  Union(this.left, this.right, {this.all: false});
 
   @override
-  bool get hasValue => _hasValue;
-
-  bool _change(String op, String value) {
-    _raw = null;
-    _op = op;
-    _value = value;
-    return _hasValue = true;
-  }
+  T deserialize(List row) => left.deserialize(row);
 
   @override
   String compile() {
-    if (_raw != null) return _raw;
-    if (_value == null) return null;
-    var v = sanitizeExpression(_value);
-    return "$_op '$v'";
-  }
-
-  void isEmpty() => equals('');
-
-  void equals(String value) {
-    _change('=', value);
-  }
-
-  void notEquals(String value) {
-    _change('!=', value);
-  }
-
-  void like(String value) {
-    _change('LIKE', value);
-  }
-
-  @override
-  void isBetween(String lower, String upper) {
-    var l = sanitizeExpression(lower), u = sanitizeExpression(upper);
-    _raw = "BETWEEN '$l' AND '$u'";
-    _hasValue = true;
-  }
-
-  @override
-  void isNotBetween(String lower, String upper) {
-    var l = sanitizeExpression(lower), u = sanitizeExpression(upper);
-    _raw = "NOT BETWEEN '$l' AND '$u'";
-    _hasValue = true;
-  }
-
-  @override
-  void isIn(Iterable<String> values) {
-    _raw = 'IN (' +
-        values.map(sanitizeExpression).map((s) => "'$s'").join(', ') +
-        ')';
-    _hasValue = true;
-  }
-
-  @override
-  void isNotIn(Iterable<String> values) {
-    _raw = 'NOT IN (' +
-        values.map(sanitizeExpression).map((s) => "'$s'").join(', ') +
-        ')';
-    _hasValue = true;
+    var selector = all == true ? 'UNION ALL' : 'UNION';
+    return '(${left.compile()}) $selector (${right.compile()})';
   }
 }
 
-class BooleanSqlExpressionBuilder implements SqlExpressionBuilder<bool> {
-  bool _hasValue = false;
-  String _op = '=', _raw;
-  bool _value;
+/// An abstract interface that performs queries.
+///
+/// This class should be implemented.
+abstract class QueryExecutor {
+  const QueryExecutor();
 
-  @override
-  bool get hasValue => _hasValue;
-
-  bool _change(String op, bool value) {
-    _raw = null;
-    _op = op;
-    _value = value;
-    return _hasValue = true;
-  }
-
-  @override
-  String compile() {
-    if (_raw != null) return _raw;
-    if (_value == null) return null;
-    var v = _value ? 'TRUE' : 'FALSE';
-    return '$_op $v';
-  }
-
-  void equals(bool value) {
-    _change('=', value);
-  }
-
-  void notEquals(bool value) {
-    _change('!=', value);
-  }
-
-  @override
-  void isBetween(bool lower, bool upper) => throw new UnsupportedError(
-      'Booleans do not support BETWEEN expressions.');
-
-  @override
-  void isNotBetween(bool lower, bool upper) => isBetween(lower, upper);
-
-  @override
-  void isIn(Iterable<bool> values) {
-    _raw = 'IN (' + values.map((b) => b ? 'TRUE' : 'FALSE').join(', ') + ')';
-    _hasValue = true;
-  }
-
-  @override
-  void isNotIn(Iterable<bool> values) {
-    _raw =
-        'NOT IN (' + values.map((b) => b ? 'TRUE' : 'FALSE').join(', ') + ')';
-    _hasValue = true;
-  }
-}
-
-class DateTimeSqlExpressionBuilder implements SqlExpressionBuilder<DateTime> {
-  final NumericSqlExpressionBuilder<int> year =
-          new NumericSqlExpressionBuilder<int>(),
-      month = new NumericSqlExpressionBuilder<int>(),
-      day = new NumericSqlExpressionBuilder<int>(),
-      hour = new NumericSqlExpressionBuilder<int>(),
-      minute = new NumericSqlExpressionBuilder<int>(),
-      second = new NumericSqlExpressionBuilder<int>();
-  final String columnName;
-  String _raw;
-
-  DateTimeSqlExpressionBuilder(this.columnName);
-
-  @override
-  bool get hasValue =>
-      _raw?.isNotEmpty == true ||
-      year.hasValue ||
-      month.hasValue ||
-      day.hasValue ||
-      hour.hasValue ||
-      minute.hasValue ||
-      second.hasValue;
-
-  bool _change(String _op, DateTime dt, bool time) {
-    var dateString = time ? dateYmdHms.format(dt) : dateYmd.format(dt);
-    _raw = '$columnName $_op \'$dateString\'';
-    return true;
-  }
-
-  operator <(DateTime value) => _change('<', value, true);
-
-  operator <=(DateTime value) => _change('<=', value, true);
-
-  operator >(DateTime value) => _change('>', value, true);
-
-  operator >=(DateTime value) => _change('>=', value, true);
-
-  void equals(DateTime value, {bool includeTime: true}) {
-    _change('=', value, includeTime != false);
-  }
-
-  void lessThan(DateTime value, {bool includeTime: true}) {
-    _change('<', value, includeTime != false);
-  }
-
-  void lessThanOrEqualTo(DateTime value, {bool includeTime: true}) {
-    _change('<=', value, includeTime != false);
-  }
-
-  void greaterThan(DateTime value, {bool includeTime: true}) {
-    _change('>', value, includeTime != false);
-  }
-
-  void greaterThanOrEqualTo(DateTime value, {bool includeTime: true}) {
-    _change('>=', value, includeTime != false);
-  }
-
-  @override
-  void isIn(Iterable<DateTime> values) {
-    _raw = '$columnName IN (' +
-        values.map(dateYmdHms.format).map((s) => '$s').join(', ') +
-        ')';
-  }
-
-  @override
-  void isNotIn(Iterable<DateTime> values) {
-    _raw = '$columnName NOT IN (' +
-        values.map(dateYmdHms.format).map((s) => '$s').join(', ') +
-        ')';
-  }
-
-  @override
-  void isBetween(DateTime lower, DateTime upper) {
-    var l = dateYmdHms.format(lower), u = dateYmdHms.format(upper);
-    _raw = "$columnName BETWEEN '$l' and '$u'";
-  }
-
-  @override
-  void isNotBetween(DateTime lower, DateTime upper) {
-    var l = dateYmdHms.format(lower), u = dateYmdHms.format(upper);
-    _raw = "$columnName NOT BETWEEN '$l' and '$u'";
-  }
-
-  @override
-  String compile() {
-    if (_raw?.isNotEmpty == true) return _raw;
-    List<String> parts = [];
-    if (year.hasValue) parts.add('YEAR($columnName) ${year.compile()}');
-    if (month.hasValue) parts.add('MONTH($columnName) ${month.compile()}');
-    if (day.hasValue) parts.add('DAY($columnName) ${day.compile()}');
-    if (hour.hasValue) parts.add('HOUR($columnName) ${hour.compile()}');
-    if (minute.hasValue) parts.add('MINUTE($columnName) ${minute.compile()}');
-    if (second.hasValue) parts.add('SECOND($columnName) ${second.compile()}');
-
-    return parts.isEmpty ? null : parts.join(' AND ');
-  }
+  Future<List<List>> query(String query);
 }
diff --git a/angel_orm/pubspec.yaml b/angel_orm/pubspec.yaml
index 5217710e..532c1230 100644
--- a/angel_orm/pubspec.yaml
+++ b/angel_orm/pubspec.yaml
@@ -10,4 +10,7 @@ dependencies:
   meta: ^1.0.0
   string_scanner: ^1.0.0
 dev_dependencies:
-  angel_model: ^1.0.0
\ No newline at end of file
+  angel_model: ^1.0.0
+  angel_serialize: ^2.0.0
+  angel_serialize_generator: ^2.0.0
+  build_runner: ^1.0.0
\ No newline at end of file