Preparation for aliased tables

moor/example/example.g.dart

@@ -55,7 +55,8 @@ class Category {
 class $CategoriesTable extends Categories
     implements TableInfo<Categories, Category> {
   final GeneratedDatabase _db;
-  $CategoriesTable(this._db);
+  final String _alias;
+  $CategoriesTable(this._db, [this._alias]);
   GeneratedIntColumn _id;
   @override
   GeneratedIntColumn get id =>
@@ -94,6 +95,11 @@ class $CategoriesTable extends Categories
     }
     return map;
   }
+
+  @override
+  $CategoriesTable createAlias(String alias) {
+    return $CategoriesTable(_db, alias);
+  }
 }
 
 class Recipe {
@@ -164,7 +170,8 @@ class Recipe {
 
 class $RecipesTable extends Recipes implements TableInfo<Recipes, Recipe> {
   final GeneratedDatabase _db;
-  $RecipesTable(this._db);
+  final String _alias;
+  $RecipesTable(this._db, [this._alias]);
   GeneratedIntColumn _id;
   @override
   GeneratedIntColumn get id =>
@@ -221,6 +228,11 @@ class $RecipesTable extends Recipes implements TableInfo<Recipes, Recipe> {
     }
     return map;
   }
+
+  @override
+  $RecipesTable createAlias(String alias) {
+    return $RecipesTable(_db, alias);
+  }
 }
 
 class Ingredient {
@@ -282,7 +294,8 @@ class Ingredient {
 class $IngredientsTable extends Ingredients
     implements TableInfo<Ingredients, Ingredient> {
   final GeneratedDatabase _db;
-  $IngredientsTable(this._db);
+  final String _alias;
+  $IngredientsTable(this._db, [this._alias]);
   GeneratedIntColumn _id;
   @override
   GeneratedIntColumn get id =>
@@ -332,6 +345,11 @@ class $IngredientsTable extends Ingredients
     }
     return map;
   }
+
+  @override
+  $IngredientsTable createAlias(String alias) {
+    return $IngredientsTable(_db, alias);
+  }
 }
 
 class IngredientInRecipe {
@@ -396,7 +414,8 @@ class IngredientInRecipe {
 class $IngredientInRecipesTable extends IngredientInRecipes
     implements TableInfo<IngredientInRecipes, IngredientInRecipe> {
   final GeneratedDatabase _db;
-  $IngredientInRecipesTable(this._db);
+  final String _alias;
+  $IngredientInRecipesTable(this._db, [this._alias]);
   GeneratedIntColumn _recipe;
   @override
   GeneratedIntColumn get recipe => _recipe ??= GeneratedIntColumn(
@@ -448,6 +467,11 @@ class $IngredientInRecipesTable extends IngredientInRecipes
     }
     return map;
   }
+
+  @override
+  $IngredientInRecipesTable createAlias(String alias) {
+    return $IngredientInRecipesTable(_db, alias);
+  }
 }
 
 abstract class _$Database extends GeneratedDatabase {

moor/lib/moor.dart

@@ -14,6 +14,7 @@ export 'package:moor/src/types/type_system.dart';
 export 'package:moor/src/runtime/expressions/comparable.dart';
 export 'package:moor/src/runtime/expressions/user_api.dart';
 export 'package:moor/src/runtime/executor/transactions.dart';
+export 'package:moor/src/runtime/statements/joins/joins.dart';
 export 'package:moor/src/runtime/statements/query.dart';
 export 'package:moor/src/runtime/statements/select.dart';
 export 'package:moor/src/runtime/statements/insert.dart';

moor/lib/src/runtime/expressions/expression.dart

@@ -19,7 +19,7 @@ abstract class Expression<D, T extends SqlType<D>> implements Component {
       Comparison.equal(this, Variable<D, T>(compare));
 }
 
-/// An expression that looks like "$a operator $b$, where $a and $b itself
+/// An expression that looks like "$a operator $b", where $a and $b itself
 /// are expressions and the operator is any string.
 abstract class InfixOperator<D, T extends SqlType<D>> with Expression<D, T> {
   Expression get left;

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

@@ -0,0 +1,9 @@
+import 'package:moor/moor.dart';
+
+/// A [SelectStatement] that operates on more than one table.
+class JoinedSelectStatement extends SelectStatement {
+  JoinedSelectStatement(QueryEngine database, TableInfo table)
+      : super(database, table);
+}
+
+abstract class JoinCreator {}

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

@@ -1,5 +1,6 @@
 import 'dart:async';
 
+import 'package:meta/meta.dart';
 import 'package:moor/moor.dart';
 import 'package:moor/src/runtime/components/component.dart';
 import 'package:moor/src/runtime/components/limit.dart';
@@ -14,6 +15,9 @@ class SelectStatement<T, D> extends Query<T, D> {
   SelectStatement(QueryEngine database, TableInfo<T, D> table)
       : super(database, table);
 
+  @visibleForOverriding
+  Set<TableInfo> get watchedTables => {table};
+
   @override
   void writeStartPart(GenerationContext ctx) {
     ctx.buffer.write('SELECT * FROM ${table.$tableName}');
@@ -51,7 +55,7 @@ class SelectStatement<T, D> extends Query<T, D> {
   Stream<List<D>> watch() {
     final query = constructQuery();
     final fetcher = QueryStreamFetcher<List<D>>(
-      readsFrom: {table},
+      readsFrom: watchedTables,
       fetchData: () => _getWithQuery(query),
       key: StreamKey(query.sql, query.boundVariables, D),
     );
@@ -124,4 +128,7 @@ class QueryRow {
 
   /// Reads a [DateTime] from the column named [key].
   DateTime readDateTime(String key) => read<DateTime>(key);
+
+  /// Reads a [Uint8List] from the column named [key].
+  Uint8List readBlob(String key) => read<Uint8List>(key);
 }

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

@@ -35,4 +35,6 @@ abstract class TableInfo<TableDsl, DataClass> {
 
   /// Maps the given row returned by the database into the fitting data class.
   DataClass map(Map<String, dynamic> data);
+
+  TableInfo<TableDsl, DataClass> createAlias(String alias);
 }

moor/test/data/tables/todos.g.dart

@@ -90,7 +90,8 @@ class TodoEntry {
 class $TodosTableTable extends TodosTable
     implements TableInfo<TodosTable, TodoEntry> {
   final GeneratedDatabase _db;
-  $TodosTableTable(this._db);
+  final String _alias;
+  $TodosTableTable(this._db, [this._alias]);
   GeneratedIntColumn _id;
   @override
   GeneratedIntColumn get id =>
@@ -159,6 +160,11 @@ class $TodosTableTable extends TodosTable
     }
     return map;
   }
+
+  @override
+  $TodosTableTable createAlias(String alias) {
+    return $TodosTableTable(_db, alias);
+  }
 }
 
 class Category {
@@ -210,7 +216,8 @@ class Category {
 class $CategoriesTable extends Categories
     implements TableInfo<Categories, Category> {
   final GeneratedDatabase _db;
-  $CategoriesTable(this._db);
+  final String _alias;
+  $CategoriesTable(this._db, [this._alias]);
   GeneratedIntColumn _id;
   @override
   GeneratedIntColumn get id =>
@@ -248,6 +255,11 @@ class $CategoriesTable extends Categories
     }
     return map;
   }
+
+  @override
+  $CategoriesTable createAlias(String alias) {
+    return $CategoriesTable(_db, alias);
+  }
 }
 
 class User {
@@ -321,7 +333,8 @@ class User {
 
 class $UsersTable extends Users implements TableInfo<Users, User> {
   final GeneratedDatabase _db;
-  $UsersTable(this._db);
+  final String _alias;
+  $UsersTable(this._db, [this._alias]);
   GeneratedIntColumn _id;
   @override
   GeneratedIntColumn get id =>
@@ -379,6 +392,11 @@ class $UsersTable extends Users implements TableInfo<Users, User> {
     }
     return map;
   }
+
+  @override
+  $UsersTable createAlias(String alias) {
+    return $UsersTable(_db, alias);
+  }
 }
 
 class SharedTodo {
@@ -429,7 +447,8 @@ class SharedTodo {
 class $SharedTodosTable extends SharedTodos
     implements TableInfo<SharedTodos, SharedTodo> {
   final GeneratedDatabase _db;
-  $SharedTodosTable(this._db);
+  final String _alias;
+  $SharedTodosTable(this._db, [this._alias]);
   GeneratedIntColumn _todo;
   @override
   GeneratedIntColumn get todo => _todo ??= GeneratedIntColumn(
@@ -470,6 +489,11 @@ class $SharedTodosTable extends SharedTodos
     }
     return map;
   }
+
+  @override
+  $SharedTodosTable createAlias(String alias) {
+    return $SharedTodosTable(_db, alias);
+  }
 }
 
 abstract class _$TodoDb extends GeneratedDatabase {

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

@@ -76,7 +76,8 @@ class TodoEntry {
 
 class $TodosTable extends Todos implements TableInfo<Todos, TodoEntry> {
   final GeneratedDatabase _db;
-  $TodosTable(this._db);
+  final String _alias;
+  $TodosTable(this._db, [this._alias]);
   GeneratedIntColumn _id;
   @override
   GeneratedIntColumn get id =>
@@ -136,6 +137,11 @@ class $TodosTable extends Todos implements TableInfo<Todos, TodoEntry> {
     }
     return map;
   }
+
+  @override
+  $TodosTable createAlias(String alias) {
+    return $TodosTable(_db, alias);
+  }
 }
 
 class Category {
@@ -187,7 +193,8 @@ class Category {
 class $CategoriesTable extends Categories
     implements TableInfo<Categories, Category> {
   final GeneratedDatabase _db;
-  $CategoriesTable(this._db);
+  final String _alias;
+  $CategoriesTable(this._db, [this._alias]);
   GeneratedIntColumn _id;
   @override
   GeneratedIntColumn get id =>
@@ -226,6 +233,11 @@ class $CategoriesTable extends Categories
     }
     return map;
   }
+
+  @override
+  $CategoriesTable createAlias(String alias) {
+    return $CategoriesTable(_db, alias);
+  }
 }
 
 abstract class _$Database extends GeneratedDatabase {

moor_flutter/pubspec.lock

@@ -59,7 +59,7 @@ packages:
       path: "../moor"
       relative: true
     source: path
-    version: "1.1.1"
+    version: "1.2.0"
   path:
     dependency: "direct main"
     description:

moor_generator/lib/src/writer/table_writer.dart

@@ -27,7 +27,8 @@ class TableWriter {
           '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 String _alias;\n')
+      ..write('${table.tableInfoName}(this._db, [this._alias]);\n');
 
     // Generate the columns
     for (var column in table.columns) {
@@ -50,6 +51,8 @@ class TableWriter {
     _writeMappingMethod(buffer);
     _writeReverseMappingMethod(buffer);
 
+    _writeAliasGenerator(buffer);
+
     // close class
     buffer.write('}');
   }
@@ -174,4 +177,14 @@ class TableWriter {
     }
     buffer.write('};\n');
   }
+
+  void _writeAliasGenerator(StringBuffer buffer) {
+    final typeName = table.tableInfoName;
+
+    buffer
+      ..write('@override\n')
+      ..write('$typeName createAlias(String alias) {\n')
+      ..write('return $typeName(_db, alias);')
+      ..write('}');
+  }
 }