Fix many-to-many

angel_orm/lib/src/join_builder.dart

@@ -31,7 +31,12 @@ class JoinBuilder {
   }
 
   String compile(Set<String> trampoline) {
-    if (to == null) return null;
+    var compiledTo = to();
+    if (compiledTo == null) {
+      print(
+          'NULLLLL $to; from $from; key: $key, value: $value, addl: $additionalFields');
+    }
+    if (compiledTo == null) return null;
     var b = StringBuffer();
     var left = '${from.tableName}.$key';
     var right = fieldName;
@@ -54,7 +59,7 @@ class JoinBuilder {
         break;
     }
 
-    b.write(' ${to()}');
+    b.write(' $compiledTo');
     if (alias != null) b.write(' $alias');
     b.write(' ON $left$op$right');
     return b.toString();

angel_orm/lib/src/query.dart

@@ -219,6 +219,8 @@ abstract class Query<T, Where extends QueryWhere> extends QueryBase<T> {
     b.write(' ');
     List<String> f;
 
+    var compiledJoins = <JoinBuilder, String>{};
+
     if (fields == null) {
       f = ['*'];
     } else {
@@ -229,10 +231,16 @@ abstract class Query<T, Where extends QueryWhere> extends QueryBase<T> {
         return ss;
       }));
       _joins.forEach((j) {
+        var c = compiledJoins[j] = j.compile(trampoline);
+        if (c != null) {
           var additional = j.additionalFields.map(j.nameFor).toList();
-        // if (!additional.contains(j.fieldName))
-        //   additional.insert(0, j.fieldName);
           f.addAll(additional);
+        } else {
+          // If compilation failed, fill in NULL placeholders.
+          for (var i = 0; i < j.additionalFields.length; i++) {
+            f.add('NULL');
+          }
+        }
       });
     }
     if (withFields) b.write(f.join(', '));
@@ -243,7 +251,7 @@ abstract class Query<T, Where extends QueryWhere> extends QueryBase<T> {
     if (preamble == null) {
       if (_crossJoin != null) b.write(' CROSS JOIN $_crossJoin');
       for (var join in _joins) {
-        var c = join.compile(trampoline);
+        var c = compiledJoins[join];
         if (c != null) b.write(' $c');
       }
     }

angel_orm_generator/lib/src/orm_build_context.dart

@@ -3,7 +3,6 @@ import 'dart:async';
 import 'package:analyzer/dart/constant/value.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
-import 'package:analyzer/src/dart/constant/value.dart';
 import 'package:angel_model/angel_model.dart';
 import 'package:angel_orm/angel_orm.dart';
 import 'package:angel_serialize/angel_serialize.dart';

angel_orm_generator/lib/src/orm_generator.dart

@@ -281,6 +281,7 @@ class OrmGenerator extends GeneratorForAnnotation<Orm> {
                   .assign(queryWhereType.newInstance([refer('this')])),
             );
 
+            // Note: this is where subquery fields for relations are added.
             ctx.relations.forEach((fieldName, relation) {
               //var name = ctx.buildContext.resolveFieldName(fieldName);
               if (relation.type == RelationshipType.belongsTo ||
@@ -289,15 +290,74 @@ class OrmGenerator extends GeneratorForAnnotation<Orm> {
                 var foreign = relation.throughContext ?? relation.foreign;
 
                 // If this is a many-to-many, add the fields from the other object.
-                var additionalFields = relation.foreign.effectiveFields
+
-                    // .where((f) => f.name != 'id' || !isSpecialId(ctx, f))
+                var additionalStrs = relation.foreign.effectiveFields.map((f) =>
-                    .map((f) => literalString(relation.foreign.buildContext
+                    relation.foreign.buildContext.resolveFieldName(f.name));
-                        .resolveFieldName(f.name)));
+                var additionalFields = additionalStrs.map(literalString);
 
                 var joinArgs = [relation.localKey, relation.foreignKey]
                     .map(literalString)
                     .toList();
 
+                // In the case of a many-to-many, we don't generate a subquery field,
+                // as it easily leads to stack overflows.
+                if (relation.isManyToMany) {
+                  // We can't simply join against the "through" table; this itself must
+                  // be a join.
+                  // (SELECT role_users.role_id, <user_fields>
+                  // FROM users
+                  // LEFT JOIN role_users ON role_users.user_id=users.id)
+                  var foreignFields = additionalStrs
+                      .map((f) => '${relation.foreign.tableName}.$f');
+                  var b = StringBuffer('(SELECT ');
+                  // role_users.role_id
+                  b.write('${relation.throughContext.tableName}');
+                  b.write('.${relation.foreignKey}');
+                  // , <user_fields>
+                  b.write(foreignFields.isEmpty
+                      ? ''
+                      : ', ' + foreignFields.join(', '));
+                  // FROM users
+                  b.write(' FROM ');
+                  b.write(relation.foreign.tableName);
+                  // LEFT JOIN role_users
+                  b.write(' LEFT JOIN ${relation.throughContext.tableName}');
+                  // Figure out which field on the "through" table points to users (foreign).
+                  var throughRelation =
+                      relation.throughContext.relations.values.firstWhere((e) {
+                    return e.foreignTable == relation.foreign.tableName;
+                  }, orElse: () {
+                    // _Role has a many-to-many to _User through _RoleUser, but
+                    // _RoleUser has no relation pointing to _User.
+                    var b = StringBuffer();
+                    b.write(ctx.buildContext.modelClassName);
+                    b.write('has a many-to-many relationship to ');
+                    b.write(relation.foreign.buildContext.modelClassName);
+                    b.write(' through ');
+                    b.write(
+                        relation.throughContext.buildContext.modelClassName);
+                    b.write(', but ');
+                    b.write(
+                        relation.throughContext.buildContext.modelClassName);
+                    b.write('has no relation pointing to ');
+                    b.write(relation.foreign.buildContext.modelClassName);
+                    b.write('.');
+                    throw b.toString();
+                  });
+
+                  // ON role_users.user_id=users.id)
+                  b.write(' ON ');
+                  b.write('${relation.throughContext.tableName}');
+                  b.write('.');
+                  b.write(throughRelation.localKey);
+                  b.write('=');
+                  b.write(relation.foreign.tableName);
+                  b.write('.');
+                  b.write(throughRelation.foreignKey);
+                  b.write(')');
+
+                  joinArgs.insert(0, literalString(b.toString()));
+                } else {
                   // In the past, we would either do a join on the table name
                   // itself, or create an instance of a query.
                   //
@@ -305,7 +365,7 @@ class OrmGenerator extends GeneratorForAnnotation<Orm> {
                   // join, so that users can customize the generated query.
                   //
                   // There'll be a private `_field`, and then a getter, named `field`,
-                // that returns the subqueryb object.
+                  // that returns the subquery object.
                   var foreignQueryType = refer(
                       foreign.buildContext.modelClassNameRecase.pascalCase +
                           'Query');
@@ -326,6 +386,7 @@ class OrmGenerator extends GeneratorForAnnotation<Orm> {
                   });
                   joinArgs.insert(
                       0, refer('_$fieldName').assign(queryInstantiation));
+                }
 
                 var joinType = relation.joinTypeString;
                 b.addExpression(refer(joinType).call(joinArgs, {

angel_orm_test/lib/src/many_to_many_test.dart

@@ -3,6 +3,7 @@ import 'dart:io';
 import 'package:angel_orm/angel_orm.dart';
 import 'package:test/test.dart';
 import 'models/user.dart';
+import 'util.dart';
 
 manyToManyTests(FutureOr<QueryExecutor> Function() createExecutor,
     {FutureOr<void> Function(QueryExecutor) close}) {
@@ -61,6 +62,7 @@ manyToManyTests(FutureOr<QueryExecutor> Function() createExecutor,
     print('=== THOSAKWE: ${thosakwe?.toJson()}');
 
     // Allow thosakwe to publish...
+    printSeparator('Allow thosakwe to publish');
     var thosakwePubQuery = RoleUserQuery();
     thosakwePubQuery.values
       ..userId = int.parse(thosakwe.id)
@@ -68,6 +70,7 @@ manyToManyTests(FutureOr<QueryExecutor> Function() createExecutor,
     await thosakwePubQuery.insert(executor);
 
     // Allow thosakwe to subscribe...
+    printSeparator('Allow thosakwe to subscribe');
     var thosakweSubQuery = RoleUserQuery();
     thosakweSubQuery.values
       ..userId = int.parse(thosakwe.id)
@@ -78,8 +81,8 @@ manyToManyTests(FutureOr<QueryExecutor> Function() createExecutor,
     // await dumpQuery('select * from users;');
     // await dumpQuery('select * from roles;');
     // await dumpQuery('select * from role_users;');
-    var query = RoleQuery()..where.id.equals(canPub.idAsInt);
+    // var query = RoleQuery()..where.id.equals(canPub.idAsInt);
-    await dumpQuery(query.compile(Set()));
+    // await dumpQuery(query.compile(Set()));
 
     print('\n');
     print('==================================================');
@@ -95,6 +98,7 @@ manyToManyTests(FutureOr<QueryExecutor> Function() createExecutor,
   }
 
   test('fetch roles for user', () async {
+    printSeparator('Fetch roles for user test');
     var user = await fetchThosakwe();
     expect(user.roles, hasLength(2));
     expect(user.roles, contains(canPub));
@@ -108,4 +112,21 @@ manyToManyTests(FutureOr<QueryExecutor> Function() createExecutor,
       expect(r.users.toList(), [thosakwe]);
     }
   });
+
+  test('only fetches linked', () async {
+    // Create a new user. The roles list should be empty,
+    // be there are no related rules.
+    var userQuery = UserQuery();
+    userQuery.values
+      ..username = 'Prince'
+      ..password = 'Rogers'
+      ..email = 'Nelson';
+    var user = await userQuery.insert(executor);
+    expect(user.roles, isEmpty);
+
+    // Fetch again, just to be doubly sure.
+    var query = UserQuery()..where.id.equals(user.idAsInt);
+    var fetched = await query.getOne(executor);
+    expect(fetched.roles, isEmpty);
+  });
 }

angel_orm_test/lib/src/models/email_indexed.g.dart

@@ -64,8 +64,10 @@ class RoleQuery extends Query<Role, RoleQueryWhere> {
     trampoline ??= Set();
     trampoline.add(tableName);
     _where = RoleQueryWhere(this);
-    leftJoin(_users = RoleUserQuery(trampoline: trampoline, parent: this),
+    leftJoin(
-        'role', 'role_role',
+        '(SELECT role_users.role_role , users.email, users.name, users.password FROM users LEFT JOIN role_users ON role_users.user_email=users.email)',
+        'role',
+        'role_role',
         additionalFields: const ['email', 'name', 'password'],
         trampoline: trampoline);
   }
@@ -75,8 +77,6 @@ class RoleQuery extends Query<Role, RoleQueryWhere> {
 
   RoleQueryWhere _where;
 
-  RoleUserQuery _users;
-
   @override
   get casts {
     return {};
@@ -119,10 +119,6 @@ class RoleQuery extends Query<Role, RoleQueryWhere> {
     return parseRow(row);
   }
 
-  RoleUserQuery get users {
-    return _users;
-  }
-
   @override
   bool canCompile(trampoline) {
     return (!(trampoline.contains('roles') &&
@@ -338,9 +334,12 @@ class UserQuery extends Query<User, UserQueryWhere> {
     trampoline ??= Set();
     trampoline.add(tableName);
     _where = UserQueryWhere(this);
-    leftJoin(_roles = RoleUserQuery(trampoline: trampoline, parent: this),
+    leftJoin(
-        'email', 'user_email',
+        '(SELECT role_users.user_email , roles.role FROM roles LEFT JOIN role_users ON role_users.role_role=roles.role)',
-        additionalFields: const ['role'], trampoline: trampoline);
+        'email',
+        'user_email',
+        additionalFields: const ['role'],
+        trampoline: trampoline);
   }
 
   @override
@@ -348,8 +347,6 @@ class UserQuery extends Query<User, UserQueryWhere> {
 
   UserQueryWhere _where;
 
-  RoleUserQuery _roles;
-
   @override
   get casts {
     return {};
@@ -395,10 +392,6 @@ class UserQuery extends Query<User, UserQueryWhere> {
     return parseRow(row);
   }
 
-  RoleUserQuery get roles {
-    return _roles;
-  }
-
   @override
   bool canCompile(trampoline) {
     return (!(trampoline.contains('users') &&

angel_orm_test/lib/src/models/unorthodox.g.dart

@@ -208,9 +208,12 @@ class WeirdJoinQuery extends Query<WeirdJoin, WeirdJoinQueryWhere> {
     leftJoin(_numbas = NumbaQuery(trampoline: trampoline, parent: this), 'id',
         'parent',
         additionalFields: const ['i', 'parent'], trampoline: trampoline);
-    leftJoin(_foos = FooPivotQuery(trampoline: trampoline, parent: this), 'id',
+    leftJoin(
+        '(SELECT foo_pivots.weird_join_id , foos.bar FROM foos LEFT JOIN foo_pivots ON foo_pivots.foo_bar=foos.bar)',
+        'id',
         'weird_join_id',
-        additionalFields: const ['bar'], trampoline: trampoline);
+        additionalFields: const ['bar'],
+        trampoline: trampoline);
   }
 
   @override
@@ -224,8 +227,6 @@ class WeirdJoinQuery extends Query<WeirdJoin, WeirdJoinQueryWhere> {
 
   NumbaQuery _numbas;
 
-  FooPivotQuery _foos;
-
   @override
   get casts {
     return {};
@@ -294,10 +295,6 @@ class WeirdJoinQuery extends Query<WeirdJoin, WeirdJoinQueryWhere> {
     return _numbas;
   }
 
-  FooPivotQuery get foos {
-    return _foos;
-  }
-
   @override
   bool canCompile(trampoline) {
     return (!(trampoline.contains('weird_joins') &&
@@ -612,9 +609,12 @@ class FooQuery extends Query<Foo, FooQueryWhere> {
     trampoline ??= Set();
     trampoline.add(tableName);
     _where = FooQueryWhere(this);
-    leftJoin(_weirdJoins = FooPivotQuery(trampoline: trampoline, parent: this),
+    leftJoin(
-        'bar', 'foo_bar',
+        '(SELECT foo_pivots.foo_bar , weird_joins.id, weird_joins.join_name FROM weird_joins LEFT JOIN foo_pivots ON foo_pivots.weird_join_id=weird_joins.id)',
-        additionalFields: const ['id', 'join_name'], trampoline: trampoline);
+        'bar',
+        'foo_bar',
+        additionalFields: const ['id', 'join_name'],
+        trampoline: trampoline);
   }
 
   @override
@@ -622,8 +622,6 @@ class FooQuery extends Query<Foo, FooQueryWhere> {
 
   FooQueryWhere _where;
 
-  FooPivotQuery _weirdJoins;
-
   @override
   get casts {
     return {};
@@ -666,10 +664,6 @@ class FooQuery extends Query<Foo, FooQueryWhere> {
     return parseRow(row);
   }
 
-  FooPivotQuery get weirdJoins {
-    return _weirdJoins;
-  }
-
   @override
   bool canCompile(trampoline) {
     return (!(trampoline.contains('foos') &&

angel_orm_test/lib/src/models/user.g.dart

@@ -66,7 +66,9 @@ class UserQuery extends Query<User, UserQueryWhere> {
     trampoline ??= Set();
     trampoline.add(tableName);
     _where = UserQueryWhere(this);
-    leftJoin(_roles = RoleUserQuery(trampoline: trampoline, parent: this), 'id',
+    leftJoin(
+        '(SELECT role_users.user_id , roles.id, roles.created_at, roles.updated_at, roles.name FROM roles LEFT JOIN role_users ON role_users.role_id=roles.id)',
+        'id',
         'user_id',
         additionalFields: const ['id', 'created_at', 'updated_at', 'name'],
         trampoline: trampoline);
@@ -77,8 +79,6 @@ class UserQuery extends Query<User, UserQueryWhere> {
 
   UserQueryWhere _where;
 
-  RoleUserQuery _roles;
-
   @override
   get casts {
     return {};
@@ -134,10 +134,6 @@ class UserQuery extends Query<User, UserQueryWhere> {
     return parseRow(row);
   }
 
-  RoleUserQuery get roles {
-    return _roles;
-  }
-
   @override
   bool canCompile(trampoline) {
     return (!(trampoline.contains('users') &&
@@ -405,7 +401,9 @@ class RoleQuery extends Query<Role, RoleQueryWhere> {
     trampoline ??= Set();
     trampoline.add(tableName);
     _where = RoleQueryWhere(this);
-    leftJoin(_users = RoleUserQuery(trampoline: trampoline, parent: this), 'id',
+    leftJoin(
+        '(SELECT role_users.role_id , users.id, users.created_at, users.updated_at, users.username, users.password, users.email FROM users LEFT JOIN role_users ON role_users.user_id=users.id)',
+        'id',
         'role_id',
         additionalFields: const [
           'id',
@@ -423,8 +421,6 @@ class RoleQuery extends Query<Role, RoleQueryWhere> {
 
   RoleQueryWhere _where;
 
-  RoleUserQuery _users;
-
   @override
   get casts {
     return {};
@@ -471,10 +467,6 @@ class RoleQuery extends Query<Role, RoleQueryWhere> {
     return parseRow(row);
   }
 
-  RoleUserQuery get users {
-    return _users;
-  }
-
   @override
   bool canCompile(trampoline) {
     return (!(trampoline.contains('roles') &&