Remove Postgres from ORM, fluent query builder, example

angel_orm/CHANGELOG.md

@@ -1,3 +1,9 @@
+# 1.0.0-alpha+11
+* Removed PostgreSQL-specific functionality, so that the ORM can ultimately
+target all services.
+* Created a better `Join` model.
+* Created a far better `Query` model.
+
 # 1.0.0-alpha+10
 * Split into `angel_orm.dart` and `server.dart`. Prevents DDC failures.
 

angel_orm/README.md

@@ -1,7 +1,6 @@
 # angel_orm
-Runtime support for Angel's ORM. Includes SQL expression generators, as well
+Runtime support for Angel's ORM. Includes a clean, database-agnostic
-as a friendly `PostgreSQLConnectionPool` class that you can use to pool connections
+query builder and relationship/join support.
-to a PostgreSQL database.
 
 For documentation about the ORM, head to the main project repo:
 https://github.com/angel-dart/orm

angel_orm/example/main.dart

@@ -0,0 +1,27 @@
+import 'package:angel_model/angel_model.dart';
+import 'package:angel_orm/angel_orm.dart';
+
+Query findEmployees(Company company) {
+  return new Query()
+    ..['company_id'] = equals(company.id)
+    ..['first_name'] = notNull() & (equals('John'))
+    ..['salary'] = greaterThanOrEqual(100000.0);
+}
+
+@ORM('api/companies')
+class Company extends Model {
+  String name;
+  bool isFortune500;
+}
+
+@orm
+class Employee extends Model {
+  @belongsTo
+  Company company;
+
+  String firstName, lastName;
+
+  double salary;
+
+  bool get isFortune500Employee => company.isFortune500;
+}

angel_orm/lib/angel_orm.dart

@@ -1,4 +1,3 @@
 export 'src/annotations.dart';
-export 'src/migration.dart';
-export 'src/relations.dart';
 export 'src/query.dart';
+export 'src/relations.dart';

angel_orm/lib/src/annotations.dart

@@ -1,12 +1,31 @@
 const ORM orm = const ORM();
 
 class ORM {
-  final String tableName;
+  /// The path to an Angel service that queries objects of the
-  const ORM([this.tableName]);
+  /// annotated type at runtime.
+  ///
+  /// Ex. `api/users`, etc.
+  final String servicePath;
+  const ORM([this.servicePath]);
 }
 
-class CanJoin {
+/// Specifies that the ORM should build a join builder
+/// that combines the results of queries on two services.
+class Join {
+  /// The [Model] type to join against.
   final Type type;
-  final String foreignKey;
+
-  const CanJoin(this.type, this.foreignKey);
+  /// The path to an Angel service that queries objects of the
+  /// [type] being joined against, at runtime.
+  ///
+  /// Ex. `api/users`, etc.
+  final String servicePath;
+
+  /// The type of join this is.
+  final JoinType joinType;
+
+  const Join(this.type, this.servicePath, [this.joinType = JoinType.join]);
 }
+
+/// The various types of [Join].
+enum JoinType { join, left, right, full, self }

angel_orm/lib/src/migration.dart

@@ -1,113 +0,0 @@
-const List<String> SQL_RESERVED_WORDS = const [
-  'SELECT', 'UPDATE', 'INSERT', 'DELETE', 'FROM', 'ASC', 'DESC', 'VALUES', 'RETURNING', 'ORDER', 'BY',
-];
-
-/// Applies additional attributes to a database column.
-class Column {
-  /// If `true`, a SQL field will be nullable.
-  final bool nullable;
-
-  /// Specifies the length of a `VARCHAR`.
-  final int length;
-
-  /// Explicitly defines a SQL type for this column.
-  final ColumnType type;
-
-  /// Specifies what kind of index this column is, if any.
-  final IndexType index;
-
-  /// The default value of this field.
-  final defaultValue;
-
-  const Column(
-      {this.nullable: true,
-      this.length,
-      this.type,
-      this.index: IndexType.NONE,
-      this.defaultValue});
-}
-
-class PrimaryKey extends Column {
-  const PrimaryKey({ColumnType columnType})
-      : super(
-            type: columnType ?? ColumnType.SERIAL,
-            index: IndexType.PRIMARY_KEY);
-}
-
-const Column primaryKey = const PrimaryKey();
-
-/// Maps to SQL index types.
-enum IndexType {
-  NONE,
-
-  /// Standard index.
-  INDEX,
-
-  /// A primary key.
-  PRIMARY_KEY,
-
-  /// A *unique* index.
-  UNIQUE
-}
-
-/// Maps to SQL data types.
-///
-/// Features all types from this list: http://www.tutorialspoint.com/sql/sql-data-types.htm
-class ColumnType {
-  /// The name of this data type.
-  final String name;
-  const ColumnType(this.name);
-
-  static const ColumnType BOOLEAN = const ColumnType('boolean');
-
-  static const ColumnType SMALL_SERIAL = const ColumnType('smallserial');
-  static const ColumnType SERIAL = const ColumnType('serial');
-  static const ColumnType BIG_SERIAL = const ColumnType('bigserial');
-
-  // Numbers
-  static const ColumnType BIG_INT = const ColumnType('bigint');
-  static const ColumnType INT = const ColumnType('int');
-  static const ColumnType SMALL_INT = const ColumnType('smallint');
-  static const ColumnType TINY_INT = const ColumnType('tinyint');
-  static const ColumnType BIT = const ColumnType('bit');
-  static const ColumnType DECIMAL = const ColumnType('decimal');
-  static const ColumnType NUMERIC = const ColumnType('numeric');
-  static const ColumnType MONEY = const ColumnType('money');
-  static const ColumnType SMALL_MONEY = const ColumnType('smallmoney');
-  static const ColumnType FLOAT = const ColumnType('float');
-  static const ColumnType REAL = const ColumnType('real');
-
-  // Dates and times
-  static const ColumnType DATE_TIME = const ColumnType('datetime');
-  static const ColumnType SMALL_DATE_TIME = const ColumnType('smalldatetime');
-  static const ColumnType DATE = const ColumnType('date');
-  static const ColumnType TIME = const ColumnType('time');
-  static const ColumnType TIME_STAMP = const ColumnType('timestamp');
-  static const ColumnType TIME_STAMP_WITH_TIME_ZONE = const ColumnType('timestamp with time zone');
-
-  // Strings
-  static const ColumnType CHAR = const ColumnType('char');
-  static const ColumnType VAR_CHAR = const ColumnType('varchar');
-  static const ColumnType VAR_CHAR_MAX = const ColumnType('varchar(max)');
-  static const ColumnType TEXT = const ColumnType('text');
-
-  // Unicode strings
-  static const ColumnType NCHAR = const ColumnType('nchar');
-  static const ColumnType NVAR_CHAR = const ColumnType('nvarchar');
-  static const ColumnType NVAR_CHAR_MAX = const ColumnType('nvarchar(max)');
-  static const ColumnType NTEXT = const ColumnType('ntext');
-
-  // Binary
-  static const ColumnType BINARY = const ColumnType('binary');
-  static const ColumnType VAR_BINARY = const ColumnType('varbinary');
-  static const ColumnType VAR_BINARY_MAX = const ColumnType('varbinary(max)');
-  static const ColumnType IMAGE = const ColumnType('image');
-
-  // Misc.
-  static const ColumnType SQL_VARIANT = const ColumnType('sql_variant');
-  static const ColumnType UNIQUE_IDENTIFIER =
-      const ColumnType('uniqueidentifier');
-  static const ColumnType XML = const ColumnType('xml');
-  static const ColumnType CURSOR = const ColumnType('cursor');
-  static const ColumnType TABLE = const ColumnType('table');
-}

angel_orm/lib/src/pool.dart

@@ -1,69 +0,0 @@
-import 'dart:async';
-import 'package:pool/pool.dart';
-import 'package:postgres/postgres.dart';
-
-/// Connects to a PostgreSQL database, whether synchronously or asynchronously.
-typedef FutureOr<PostgreSQLConnection> PostgreSQLConnector();
-
-/// Pools connections to a PostgreSQL database.
-class PostgreSQLConnectionPool {
-  final List<PostgreSQLConnection> _connections = [];
-  final List<int> _opened = [];
-  int _index = 0;
-  Pool _pool;
-
-  /// The maximum number of concurrent connections to the database.
-  ///
-  /// Default: `5`
-  final int concurrency;
-
-  /// An optional timeout for pooled connections to execute.
-  final Duration timeout;
-
-  /// A function that connects this pool to the database, on-demand.
-  final PostgreSQLConnector connector;
-
-  PostgreSQLConnectionPool(this.connector,
-      {this.concurrency: 5, this.timeout}) {
-    _pool = new Pool(concurrency, timeout: timeout);
-  }
-
-  Future<PostgreSQLConnection> _connect() async {
-    if (_connections.isEmpty) {
-      for (int i = 0; i < concurrency; i++) {
-        _connections.add(await connector());
-      }
-    }
-
-    var connection = _connections[_index++];
-    if (_index >= _connections.length) _index = 0;
-
-    if (!_opened.contains(connection.hashCode)) {
-      await connection.open();
-      _opened.add(connection.hashCode);
-    }
-
-    return connection;
-  }
-
-  Future close() => Future.wait(_connections.map((c) => c.close()));
-
-  /// Connects to the database, and then executes the [callback].
-  ///
-  /// Returns the result of [callback].
-  Future<T> run<T>(FutureOr<T> callback(PostgreSQLConnection connection)) {
-    return _pool.request().then((resx) {
-      return _connect().then((connection) {
-        return new Future<T>.sync(() => callback(connection))
-            .whenComplete(() async {
-          if (connection.isClosed) {
-            _connections
-              ..remove(connection)
-              ..add(await connector());
-          }
-          resx.release();
-        });
-      });
-    });
-  }
-}

angel_orm/lib/src/query.dart

@@ -1,332 +1,114 @@
-import 'package:meta/meta.dart';
+/// Expects a field to be equal to a given [value].
-import 'package:intl/intl.dart';
+Predicate<T> equals<T>(T value) =>
-import 'package:string_scanner/string_scanner.dart';
+    new Predicate<T>._(PredicateType.equals, value);
 
-final DateFormat DATE_YMD = new DateFormat('yyyy-MM-dd');
+/// Expects at least one of the given [predicates] to be true.
-final DateFormat DATE_YMD_HMS = new DateFormat('yyyy-MM-dd HH:mm:ss');
+Predicate<T> anyOf<T>(Iterable<Predicate<T>> predicates) =>
+    new MultiPredicate<T>._(PredicateType.any, predicates);
 
-/// Cleans an input SQL expression of common SQL injection points.
+/// Expects a field to be contained within a set of [values].
-String sanitizeExpression(String unsafe) {
+Predicate<T> isIn<T>(Iterable<T> values) => new Predicate<T>._(PredicateType.isIn, null, values);
-  var buf = new StringBuffer();
-  var scanner = new StringScanner(unsafe);
-  int ch;
 
-  while (!scanner.isDone) {
+/// Expects a field to be `null`.
-    // Ignore comment starts
+Predicate<T> isNull<T>() => equals(null);
-    if (scanner.scan('--') || scanner.scan('/*'))
-      continue;
 
-    // Ignore all single quotes and attempted escape sequences
+/// Expects a given [predicate] to not be true.
-    else if (scanner.scan("'") || scanner.scan('\\'))
+Predicate<T> not<T>(Predicate<T> predicate) =>
-      continue;
+    new MultiPredicate<T>._(PredicateType.negate, [predicate]);
 
-    // Otherwise, add the next char, unless it's a null byte.
+/// Expects a field to be not be `null`.
-    else if ((ch = scanner.readChar()) != 0 && ch != null)
+Predicate<T> notNull<T>() => not(isNull());
-      buf.writeCharCode(ch);
+
+/// Expects a field to be less than a given [value].
+Predicate<T> lessThan<T>(T value) =>
+    new Predicate<T>._(PredicateType.less, value);
+
+/// Expects a field to be less than or equal to a given [value].
+Predicate<T> lessThanOrEqual<T>(T value) => lessThan(value) | equals(value);
+
+/// Expects a field to be greater than a given [value].
+Predicate<T> greaterThan<T>(T value) =>
+    new Predicate<T>._(PredicateType.greater, value);
+
+/// Expects a field to be greater than or equal to a given [value].
+Predicate<T> greaterThanOrEqual<T>(T value) =>
+    greaterThan(value) | equals(value);
+
+/// A generic query class.
+///
+/// Angel services can translate these into driver-specific queries.
+/// This allows the Angel ORM to be flexible and support multiple platforms.
+class Query {
+  final Map<String, Predicate> _fields = {};
+  final Map<String, SortType> _sort = {};
+
+  /// Each field in a query is actually a [Predicate], and therefore acts as a contract
+  /// with the underlying service.
+  Map<String, Predicate> get fields =>
+      new Map<String, Predicate>.unmodifiable(_fields);
+
+  /// The sorting order applied to this query.
+  Map<String, SortType> get sorting =>
+      new Map<String, SortType>.unmodifiable(_sort);
+
+  /// Sets the [Predicate] assigned to the given [key].
+  void operator []=(String key, Predicate value) => _fields[key] = value;
+
+  /// Gets the [Predicate] assigned to the given [key].
+  Predicate operator [](String key) => _fields[key];
+
+  /// Sort output by the given [key].
+  void sortBy(String key, [SortType type = SortType.descending]) =>
+      _sort[key] = type;
 }
 
-  return buf.toString();
+/// A mechanism used to express an expectation about some object ([target]).
+class Predicate<T> {
+  /// The type of expectation we are declaring.
+  final PredicateType type;
+
+  /// The single argument of this target.
+  final T target;
+  final Iterable<T> args;
+
+  Predicate._(this.type, this.target, [this.args]);
+
+  Predicate<T> operator &(Predicate<T> other) => and(other);
+
+  Predicate<T> operator |(Predicate<T> other) => or(other);
+
+  Predicate<T> and(Predicate<T> other) {
+    return new MultiPredicate._(PredicateType.and, [this, other]);
   }
 
-abstract class SqlExpressionBuilder {
+  Predicate<T> or(Predicate<T> other) {
-  bool get hasValue;
+    return new MultiPredicate._(PredicateType.or, [this, other]);
-  String compile();
-  void isBetween(lower, upper);
-  void isNotBetween(lower, upper);
-  void isIn(Iterable values);
-  void isNotIn(Iterable values);
-}
-
-class NumericSqlExpressionBuilder<T extends num>
-    implements SqlExpressionBuilder {
-  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(@checked T lower, @checked T upper) {
-    _raw = 'BETWEEN $lower AND $upper';
-    _hasValue = true;
-  }
-
-  @override
-  void isNotBetween(@checked T lower, @checked T upper) {
-    _raw = 'NOT BETWEEN $lower AND $upper';
-    _hasValue = true;
-  }
-
-  @override
-  void isIn(@checked Iterable<T> values) {
-    _raw = 'IN (' + values.join(', ') + ')';
-    _hasValue = true;
-  }
-
-  @override
-  void isNotIn(@checked Iterable<T> values) {
-    _raw = 'NOT IN (' + values.join(', ') + ')';
-    _hasValue = true;
   }
 }
 
-class StringSqlExpressionBuilder implements SqlExpressionBuilder {
+/// An advanced [Predicate] that performs an operation of multiple other predicates.
-  bool _hasValue = false;
+class MultiPredicate<T> extends Predicate<T> {
-  String _op = '=', _raw, _value;
+  final Iterable<Predicate<T>> targets;
 
-  @override
+  MultiPredicate._(PredicateType type, this.targets) : super._(type, null);
-  bool get hasValue => _hasValue;
 
-  bool _change(String op, String value) {
+  /// Use [targets] instead.
-    _raw = null;
+  @deprecated
-    _op = op;
+  T get target => throw new UnsupportedError(
-    _value = value;
+      'IterablePredicate has no `target`. Use `targets` instead.');
-    return _hasValue = true;
 }
 
-  @override
+/// The various types of predicate.
-  String compile() {
+enum PredicateType {
-    if (_raw != null) return _raw;
+  equals,
-    if (_value == null) return null;
+  any,
-    var v = sanitizeExpression(_value);
+  isIn,
-    return "$_op '$v'";
+  negate,
+  and,
+  or,
+  less,
+  greater,
 }
 
-  void isEmpty() => equals('');
+/// The various modes of sorting.
-
+enum SortType { ascending, descending }
-  void equals(String value) {
-    _change('=', value);
-  }
-
-  void notEquals(String value) {
-    _change('!=', value);
-  }
-
-  void like(String value) {
-    _change('LIKE', value);
-  }
-
-  @override
-  void isBetween(@checked String lower, @checked String upper) {
-    var l = sanitizeExpression(lower), u = sanitizeExpression(upper);
-    _raw = "BETWEEN '$l' AND '$u'";
-    _hasValue = true;
-  }
-
-  @override
-  void isNotBetween(@checked String lower, @checked String upper) {
-    var l = sanitizeExpression(lower), u = sanitizeExpression(upper);
-    _raw = "NOT BETWEEN '$l' AND '$u'";
-    _hasValue = true;
-  }
-
-  @override
-  void isIn(@checked Iterable<String> values) {
-    _raw = 'IN (' +
-        values.map(sanitizeExpression).map((s) => "'$s'").join(', ') +
-        ')';
-    _hasValue = true;
-  }
-
-  @override
-  void isNotIn(@checked Iterable<String> values) {
-    _raw = 'NOT IN (' +
-        values.map(sanitizeExpression).map((s) => "'$s'").join(', ') +
-        ')';
-    _hasValue = true;
-  }
-}
-
-class BooleanSqlExpressionBuilder implements SqlExpressionBuilder {
-  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 $v';
-  }
-
-  void equals(bool value) {
-    _change('=', value);
-  }
-
-  void notEquals(bool value) {
-    _change('!=', value);
-  }
-
-  @override
-  void isBetween(@checked bool lower, @checked bool upper) =>
-      throw new UnsupportedError(
-          'Booleans do not support BETWEEN expressions.');
-
-  @override
-  void isNotBetween(@checked bool lower, @checked bool upper) =>
-      isBetween(lower, upper);
-
-  @override
-  void isIn(@checked Iterable<bool> values) {
-    _raw = 'IN (' + values.map((b) => b ? 'TRUE' : 'FALSE').join(', ') + ')';
-    _hasValue = true;
-  }
-
-  @override
-  void isNotIn(@checked Iterable<bool> values) {
-    _raw =
-        'NOT IN (' + values.map((b) => b ? 'TRUE' : 'FALSE').join(', ') + ')';
-    _hasValue = true;
-  }
-}
-
-class DateTimeSqlExpressionBuilder implements SqlExpressionBuilder {
-  final NumericSqlExpressionBuilder<int> year =
-          new NumericSqlExpressionBuilder<int>(),
-      month = new NumericSqlExpressionBuilder<int>(),
-      day = new NumericSqlExpressionBuilder<int>(),
-      hour = new NumericSqlExpressionBuilder<int>(),
-      minute = new NumericSqlExpressionBuilder<int>(),
-      second = new NumericSqlExpressionBuilder<int>();
-  final String columnName;
-  String _raw;
-
-  DateTimeSqlExpressionBuilder(this.columnName);
-
-  @override
-  bool get hasValue =>
-      _raw?.isNotEmpty == true ||
-      year.hasValue ||
-      month.hasValue ||
-      day.hasValue ||
-      hour.hasValue ||
-      minute.hasValue ||
-      second.hasValue;
-
-  bool _change(String _op, DateTime dt, bool time) {
-    var dateString = time ? DATE_YMD_HMS.format(dt) : DATE_YMD.format(dt);
-    _raw = '$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(@checked Iterable<DateTime> values) {
-    _raw = '$columnName IN (' +
-        values.map(DATE_YMD_HMS.format).map((s) => '$s').join(', ') +
-        ')';
-  }
-
-  @override
-  void isNotIn(@checked Iterable<DateTime> values) {
-    _raw = '$columnName NOT IN (' +
-        values.map(DATE_YMD_HMS.format).map((s) => '$s').join(', ') +
-        ')';
-  }
-
-  @override
-  void isBetween(@checked DateTime lower, @checked DateTime upper) {
-    var l = DATE_YMD_HMS.format(lower), u = DATE_YMD_HMS.format(upper);
-    _raw = "$columnName BETWEEN '$l' and '$u'";
-  }
-
-  @override
-  void isNotBetween(@checked DateTime lower, @checked DateTime upper) {
-    var l = DATE_YMD_HMS.format(lower), u = DATE_YMD_HMS.format(upper);
-    _raw = "$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 ');
-  }
-}

angel_orm/pubspec.yaml

@@ -1,13 +1,10 @@
 name: angel_orm
-version: 1.0.0-alpha+12
+version: 1.0.0-alpha+11
 description: Runtime support for Angel's ORM.
 author: Tobe O <thosakwe@gmail.com>
 homepage: https://github.com/angel-dart/orm
 environment:
-  sdk: ">=1.19.0"
+  sdk: '>=2.0.0-dev.1.2 <2.0.0'
 dependencies:
-  intl: ">=0.0.0 <1.0.0"
+  angel_model: ^1.0.0
   meta: ^1.0.0
-  pool: ^1.0.0
-  postgres: ^0.9.5
-  string_scanner: ^1.0.0

angel_orm_generator/test/models/order.dart

@@ -9,7 +9,7 @@ part 'order.g.dart';
 @orm
 @serializable
 class _Order extends Model {
-  @CanJoin(Customer, 'id')
+  @Join(Customer, 'id')
   int customerId;
   int employeeId;
   DateTime orderDate;