Custom table constraints

moor/lib/src/dsl/table.dart

@@ -25,8 +25,8 @@ abstract class Table {
   ///  @override
   ///  Set<Column> get primaryKey => {recipe, ingredient};
   ///
-  ///  IntColumn get recipe => integer().autoIncrement()();
+  ///  IntColumn get recipe => integer()();
-  ///  IntColumn get ingredient => integer().autoIncrement()();
+  ///  IntColumn get ingredient => integer()();
   ///
   ///  IntColumn get amountInGrams => integer().named('amount')();
   ///}
@@ -39,6 +39,14 @@ abstract class Table {
   @visibleForOverriding
   Set<Column> get primaryKey => null;
 
+  /// Custom table constraints that should be added to the table.
+  ///
+  /// See also:
+  ///  - https://www.sqlite.org/syntax/table-constraint.html, which defines what
+  ///    table constraints are supported.
+  @visibleForOverriding
+  List<String> get customConstraints => [];
+
   /// Use this as the body of a getter to declare a column that holds integers.
   /// Example (inside the body of a table class):
   /// ```

moor/lib/src/runtime/components/join.dart

@@ -10,7 +10,7 @@ const Map<JoinType, String> _joinKeywords = {
   JoinType.cross: 'CROSS',
 };
 
-class Join<T, D> extends Component {
+class Join<T extends Table, D> extends Component {
   final JoinType type;
   final TableInfo<T, D> table;
   final Expression<bool, BoolType> on;
@@ -35,7 +35,8 @@ class Join<T, D> extends Component {
 ///
 /// See also:
 ///  - http://www.sqlitetutorial.net/sqlite-inner-join/
-Join innerJoin<T, D>(TableInfo<T, D> other, Expression<bool, BoolType> on) {
+Join innerJoin<T extends Table, D>(
+    TableInfo<T, D> other, Expression<bool, BoolType> on) {
   return Join(JoinType.inner, other, on);
 }
 
@@ -44,7 +45,8 @@ Join innerJoin<T, D>(TableInfo<T, D> other, Expression<bool, BoolType> on) {
 ///
 /// See also:
 ///  - http://www.sqlitetutorial.net/sqlite-left-join/
-Join leftOuterJoin<T, D>(TableInfo<T, D> other, Expression<bool, BoolType> on) {
+Join leftOuterJoin<T extends Table, D>(
+    TableInfo<T, D> other, Expression<bool, BoolType> on) {
   return Join(JoinType.leftOuter, other, on);
 }
 

moor/lib/src/runtime/database.dart

@@ -75,7 +75,7 @@ abstract class DatabaseConnectionUser {
   ///   innerJoin(destination, routes.startPoint.equalsExp(destination.id)),
   /// ]);
   /// ```
-  T alias<T, D>(TableInfo<T, D> table, String alias) {
+  T alias<T extends Table, D>(TableInfo<T, D> table, String alias) {
     return table.createAlias(alias).asDslTable;
   }
 }
@@ -87,7 +87,7 @@ mixin QueryEngine on DatabaseConnectionUser {
   /// to write data into the [table] by using [InsertStatement.insert].
   @protected
   @visibleForTesting
-  InsertStatement<T> into<T>(TableInfo<dynamic, T> table) =>
+  InsertStatement<T> into<T>(TableInfo<Table, T> table) =>
       InsertStatement<T>(this, table);
 
   /// Starts an [UpdateStatement] for the given table. You can use that
@@ -95,7 +95,7 @@ mixin QueryEngine on DatabaseConnectionUser {
   /// clause on that table and then use [UpdateStatement.write].
   @protected
   @visibleForTesting
-  UpdateStatement<Tbl, ReturnType> update<Tbl, ReturnType>(
+  UpdateStatement<Tbl, ReturnType> update<Tbl extends Table, ReturnType>(
           TableInfo<Tbl, ReturnType> table) =>
       UpdateStatement(this, table);
 
@@ -104,17 +104,17 @@ mixin QueryEngine on DatabaseConnectionUser {
   /// stream of data
   @protected
   @visibleForTesting
-  SimpleSelectStatement<Table, ReturnType> select<Table, ReturnType>(
+  SimpleSelectStatement<T, ReturnType> select<T extends Table, ReturnType>(
-      TableInfo<Table, ReturnType> table) {
+      TableInfo<T, ReturnType> table) {
-    return SimpleSelectStatement<Table, ReturnType>(this, table);
+    return SimpleSelectStatement<T, ReturnType>(this, table);
   }
 
   /// Starts a [DeleteStatement] that can be used to delete rows from a table.
   @protected
   @visibleForTesting
-  DeleteStatement<Table, Entity> delete<Table, Entity>(
+  DeleteStatement<T, Entity> delete<T extends Table, Entity>(
-      TableInfo<Table, Entity> table) {
+      TableInfo<T, Entity> table) {
-    return DeleteStatement<Table, Entity>(this, table);
+    return DeleteStatement<T, Entity>(this, table);
   }
 
   /// Executes a custom delete or update statement and returns the amount of

moor/lib/src/runtime/migration.dart

@@ -53,19 +53,17 @@ class Migrator {
 
   /// Creates the given table if it doesn't exist
   Future<void> createTable(TableInfo table) async {
-    final sql = StringBuffer();
+    final sql = StringBuffer()
-
+      ..write('CREATE TABLE IF NOT EXISTS ${table.$tableName} (');
-    // ignore: cascade_invocations
-    sql.write('CREATE TABLE IF NOT EXISTS ${table.$tableName} (');
 
     var hasAutoIncrement = false;
     for (var i = 0; i < table.$columns.length; i++) {
       final column = table.$columns[i];
 
-      if (column is GeneratedIntColumn && column.hasAutoIncrement)
+      if (column is GeneratedIntColumn && column.hasAutoIncrement) {
         hasAutoIncrement = true;
+      }
 
-      // ignore: cascade_invocations
       column.writeColumnDefinition(sql);
 
       if (i < table.$columns.length - 1) sql.write(', ');
@@ -84,6 +82,16 @@ class Migrator {
       sql.write(')');
     }
 
+    final constraints = table.asDslTable.customConstraints ?? [];
+
+    for (var i = 0; i < constraints.length; i++) {
+      if (i != 0) {
+        sql.write(', ');
+      }
+
+      sql.write(constraints[i]);
+    }
+
     sql.write(');');
 
     return issueCustomQuery(sql.toString());

moor/lib/src/runtime/statements/delete.dart

@@ -5,7 +5,7 @@ import 'package:moor/src/runtime/components/component.dart';
 import 'package:moor/src/runtime/statements/query.dart';
 import 'package:moor/src/runtime/structure/table_info.dart';
 
-class DeleteStatement<T, D> extends Query<T, D>
+class DeleteStatement<T extends Table, D> extends Query<T, D>
     with SingleTableQueryMixin<T, D> {
   /// This constructor should be called by [GeneratedDatabase.delete] for you.
   DeleteStatement(QueryEngine database, TableInfo<T, D> table)

moor/lib/src/runtime/statements/insert.dart

@@ -9,7 +9,7 @@ class InsertStatement<DataClass> {
   @protected
   final QueryEngine database;
   @protected
-  final TableInfo<dynamic, DataClass> table;
+  final TableInfo<Table, DataClass> table;
 
   bool _orReplace = false;
 

moor/lib/src/runtime/statements/query.dart

@@ -1,4 +1,5 @@
 import 'package:meta/meta.dart';
+import 'package:moor/src/dsl/table.dart';
 import 'package:moor/src/runtime/components/component.dart';
 import 'package:moor/src/runtime/components/limit.dart';
 import 'package:moor/src/runtime/components/order_by.dart';
@@ -12,10 +13,10 @@ import 'package:moor/src/runtime/structure/table_info.dart';
 
 /// Statement that operates with data that already exists (select, delete,
 /// update).
-abstract class Query<Table, DataClass> {
+abstract class Query<T extends Table, DataClass> {
   @protected
   QueryEngine database;
-  TableInfo<Table, DataClass> table;
+  TableInfo<T, DataClass> table;
 
   Query(this.database, this.table);
 
@@ -67,8 +68,8 @@ abstract class Query<Table, DataClass> {
   }
 }
 
-mixin SingleTableQueryMixin<Table, DataClass> on Query<Table, DataClass> {
+mixin SingleTableQueryMixin<T extends Table, DataClass> on Query<T, DataClass> {
-  void where(Expression<bool, BoolType> filter(Table tbl)) {
+  void where(Expression<bool, BoolType> filter(T tbl)) {
     final predicate = filter(table.asDslTable);
 
     if (whereExpr == null) {
@@ -119,7 +120,7 @@ mixin SingleTableQueryMixin<Table, DataClass> on Query<Table, DataClass> {
   }
 }
 
-mixin LimitContainerMixin<T, D> on Query<T, D> {
+mixin LimitContainerMixin<T extends Table, D> on Query<T, D> {
   /// Limits the amount of rows returned by capping them at [limit]. If [offset]
   /// is provided as well, the first [offset] rows will be skipped and not
   /// included in the result.

moor/lib/src/runtime/statements/select.dart

@@ -13,8 +13,8 @@ import 'package:moor/src/runtime/structure/table_info.dart';
 
 typedef OrderingTerm OrderClauseGenerator<T>(T tbl);
 
-class JoinedSelectStatement<FirstT, FirstD> extends Query<FirstT, FirstD>
+class JoinedSelectStatement<FirstT extends Table, FirstD>
-    with LimitContainerMixin {
+    extends Query<FirstT, FirstD> with LimitContainerMixin {
   JoinedSelectStatement(
       QueryEngine database, TableInfo<FirstT, FirstD> table, this._joins)
       : super(database, table);
@@ -142,7 +142,7 @@ class JoinedSelectStatement<FirstT, FirstD> extends Query<FirstT, FirstD>
 }
 
 /// A select statement that doesn't use joins
-class SimpleSelectStatement<T, D> extends Query<T, D>
+class SimpleSelectStatement<T extends Table, D> extends Query<T, D>
     with SingleTableQueryMixin<T, D>, LimitContainerMixin<T, D> {
   SimpleSelectStatement(QueryEngine database, TableInfo<T, D> table)
       : super(database, table);
@@ -288,7 +288,7 @@ class TypedResult {
   final QueryRow rawData;
 
   /// Reads all data that belongs to the given [table] from this row.
-  D readTable<T, D>(TableInfo<T, D> table) {
+  D readTable<T extends Table, D>(TableInfo<T, D> table) {
     return _parsedData[table] as D;
   }
 }

moor/lib/src/runtime/statements/update.dart

@@ -3,7 +3,7 @@ import 'dart:async';
 import 'package:moor/moor.dart';
 import 'package:moor/src/runtime/components/component.dart';
 
-class UpdateStatement<T, D> extends Query<T, D>
+class UpdateStatement<T extends Table, D> extends Query<T, D>
     with SingleTableQueryMixin<T, D> {
   UpdateStatement(QueryEngine database, TableInfo<T, D> table)
       : super(database, table);

moor/lib/src/runtime/structure/table_info.dart

@@ -4,7 +4,7 @@ import 'package:moor/src/runtime/expressions/variables.dart';
 /// Base class for generated classes. [TableDsl] is the type specified by the
 /// user that extends [Table], [DataClass] is the type of the data class
 /// generated from the table.
-mixin TableInfo<TableDsl, DataClass> {
+mixin TableInfo<TableDsl extends Table, DataClass> {
   /// Type system sugar. Implementations are likely to inherit from both
   /// [TableInfo] and [TableDsl] and can thus just return their instance.
   TableDsl get asDslTable;

moor_flutter/example/lib/database/database.dart

@@ -11,7 +11,9 @@ class Todos extends Table {
 
   DateTimeColumn get targetDate => dateTime().nullable()();
 
-  IntColumn get category => integer().nullable()();
+  IntColumn get category => integer()
+      .nullable()
+      .customConstraint('NULLABLE REFERENCES categories(id)')();
 }
 
 @DataClassName('Category')

moor_flutter/example/lib/database/database.g.dart

@@ -126,11 +126,8 @@ class $TodosTable extends Todos with TableInfo<$TodosTable, TodoEntry> {
   GeneratedIntColumn _constructCategory() {
     var cName = 'category';
     if (_alias != null) cName = '$_alias.$cName';
-    return GeneratedIntColumn(
+    return GeneratedIntColumn('category', $tableName, true,
-      'category',
+        $customConstraints: 'NULLABLE REFERENCES categories(id)');
-      $tableName,
-      true,
-    );
   }
 
   @override