Bug fixes and support for dart placeholder

drift_dev/lib/src/analyzer/sql_queries/type_mapping.dart

@@ -107,11 +107,11 @@ class TypeMapper {
     return engineView;
   }
 
-  /// Extracts variables and Dart templates from the [ctx]. Variables are
-  /// sorted by their ascending index. Placeholders are sorted by the position
-  /// they have in the query. When comparing variables and placeholders, the
-  /// variable comes first if the first variable with the same index appears
-  /// before the placeholder.
+  /// Extracts variables and Dart templates from the AST tree starting at
+  /// [root], but nested queries are excluded. Variables are sorted by their
+  /// ascending index. Placeholders are sorted by the position they have in the
+  /// query. When comparing variables and placeholders, the variable comes first
+  /// if the first variable with the same index appears before the placeholder.
   ///
   /// Additionally, the following assumptions can be made if this method returns
   /// without throwing:
@@ -125,14 +125,16 @@ class TypeMapper {
     // this contains variable references. For instance, SELECT :a = :a would
     // contain two entries, both referring to the same variable. To do that,
     // we use the fact that each variable has a unique index.
-    final collector = _VariableCollector();
-    root.accept(collector, null);
+    final variableCollector = _ElementCollector<Variable>();
+    final placeholderCollector = _ElementCollector<DartPlaceholder>();
 
-    final variables = collector.result;
-    final placeholders =
-        root.allDescendants.whereType<DartPlaceholder>().toList();
+    root.accept(variableCollector, null);
+    root.accept(placeholderCollector, null);
 
-    final merged = _mergeVarsAndPlaceholders(variables, placeholders);
+    final merged = _mergeVarsAndPlaceholders(
+      variableCollector.result,
+      placeholderCollector.result,
+    );
 
     final foundElements = <FoundElement>[];
     // we don't allow variables with an explicit index after an array. For
@@ -356,16 +358,24 @@ class TypeMapper {
   }
 }
 
-/// Because nested variables should not be included when extracting all
-/// FoundElements allDescendants.whereType<Variable>() no longer works.
-class _VariableCollector extends RecursiveVisitor<void, void> {
-  final List<Variable> result;
+/// Because FoundElements from nested queries should not be added to the parent
+/// query, it is necessary to use a visitor to decide when to stop collection
+/// elements.
+///
+/// [T] can either be a [Variable] or [DartPlaceholder]. If the type is anything
+/// else the result list will be empty.
+class _ElementCollector<T> extends RecursiveVisitor<void, void> {
+  final List<T> result;
 
-  _VariableCollector() : result = [];
+  _ElementCollector()
+      : result = [],
+        assert(T == Variable || T == DartPlaceholder, 'T is: $T');
 
   @override
   void visitVariable(Variable e, void arg) {
-    result.add(e);
+    if (T == Variable) {
+      result.add(e as T);
+    }
 
     super.visitVariable(e, arg);
   }
@@ -373,8 +383,13 @@ class _VariableCollector extends RecursiveVisitor<void, void> {
   @override
   void visitMoorSpecificNode(MoorSpecificNode e, void arg) {
     if (e is NestedQueryColumn) {
+      // If the node ist a nested query, return to avoid collecting elements
+      // inside of it
       return;
     }
+    if (e is DartPlaceholder && T == DartPlaceholder) {
+      result.add(e as T);
+    }
 
     super.visitMoorSpecificNode(e, arg);
   }

drift_dev/lib/src/model/sql_query.dart

@@ -521,18 +521,12 @@ class NestedResultQuery extends NestedResult {
     required this.query,
   });
 
-  String filedName(String? nestedPrefix) {
+  String filedName() {
     if (from.as != null) {
       return from.as!;
     }
 
-    final name = ReCase(query.resultClassName).camelCase;
-
-    if (nestedPrefix != null) {
-      return name + nestedPrefix;
-    }
-
-    return name;
+    return ReCase(query.name).camelCase;
   }
 
   String resultTypeCode(String parentResultClassName) {

drift_dev/lib/src/writer/queries/query_writer.dart

@@ -45,7 +45,8 @@ class QueryWriter {
     // We do this transformation so late because it shouldn't have an impact on
     // analysis, Dart getter names stay the same.
     if (resultSet != null && options.newSqlCodeGeneration) {
-      ExplicitAliasTransformer().rewrite(query.root!);
+      _transformer = ExplicitAliasTransformer();
+      _transformer.rewrite(query.root!);
       NestedQueryTransformer().rewrite(query.root!);
     }
 
@@ -61,6 +62,12 @@ class QueryWriter {
   }
 
   void _writeSelect(SqlSelectQuery select) {
+    if (select.hasNestedQuery && !scope.options.newSqlCodeGeneration) {
+      throw UnsupportedError(
+        'To use nested result queries enable new_sql_code_generation',
+      );
+    }
+
     _writeSelectStatementCreator(select);
 
     if (!select.declaredInMoorFile && !options.compactQueryMethods) {
@@ -140,16 +147,7 @@ class QueryWriter {
           _buffer.write('$fieldName: $tableGetter.$mappingMethod(row, '
               'tablePrefix: ${asDartLiteral(prefix)}),');
         } else if (nested is NestedResultQuery) {
-          if (!scope.options.newSqlCodeGeneration) {
-            throw UnsupportedError(
-              'To use nested result queries enable new_sql_code_generation',
-            );
-          }
-
-          final prefix = resultSet.nestedPrefixFor(nested);
-          if (prefix == null) continue;
-
-          final fieldName = nested.filedName(prefix);
+          final fieldName = nested.filedName();
           _buffer.write('$fieldName: await ');
 
           _writeCustomSelectStatement(nested.query);
@@ -554,7 +552,9 @@ class QueryWriter {
       _buffer.write('${table.dbGetterName},');
     }
 
-    for (final element in select.elements.whereType<FoundDartPlaceholder>()) {
+    for (final element in select
+        .elementsWithNestedQueries()
+        .whereType<FoundDartPlaceholder>()) {
       _buffer.write('...${placeholderContextName(element)}.watchedTables,');
     }
 
@@ -686,7 +686,7 @@ class _ExpandedDeclarationWriter {
     }
 
     needsIndexCounter = true;
-    for (final element in query.elements) {
+    for (final element in query.elementsWithNestedQueries()) {
       if (element is FoundVariable) {
         if (element.isArray) {
           _writeArrayVariable(element);

drift_dev/lib/src/writer/queries/result_set_writer.dart

@@ -52,8 +52,7 @@ class ResultSetWriter {
         fieldNames.add(fieldName);
         if (!nested.isNullable) nonNullableFields.add(fieldName);
       } else if (nested is NestedResultQuery) {
-        final nestedPrefix = resultSet.nestedPrefixFor(nested);
-        final fieldName = nested.filedName(nestedPrefix);
+        final fieldName = nested.filedName();
         final typeName = nested.resultTypeCode(className);
 
         if (nested.query.resultSet.needsOwnClass) {

sqlparser/lib/src/analysis/schema/references.dart

@@ -100,11 +100,7 @@ class ReferenceScope {
   ///
   /// If [includeParents] is set to false, resolve will only search the current
   /// scope.
-  T? resolve<T extends Referencable>(
-    String name, {
-    Function()? orElse,
-    bool includeParents = true,
-  }) {
+  T? resolve<T extends Referencable>(String name, {Function()? orElse}) {
     ReferenceScope? scope = this;
     var isAtParent = false;
     final upper = name.toUpperCase();
@@ -122,8 +118,6 @@ class ReferenceScope {
 
       scope = scope.parent;
       isAtParent = true;
-
-      if (!includeParents) break;
     }
 
     if (orElse != null) orElse();

sqlparser/lib/src/analysis/steps/nested_query_resolver.dart

@@ -34,8 +34,7 @@ class _NestedQueryTransformer extends Transformer<void> {
   AstNode? visitReference(Reference e, void arg) {
     // if the scope of the nested query cannot resolve the reference, the
     // reference needs to be retrieved from the parent query
-    if (e.entityName != null &&
-        e.scope.resolve(e.entityName!, includeParents: false) == null) {
+    if (e.resultEntity != null && e.resultEntity!.origin.scope != e.scope) {
       final result = e.scope.resolve(e.entityName!);
 
       if (result == null) {
@@ -62,7 +61,7 @@ class _NestedQueryTransformer extends Transformer<void> {
 
       return e;
     } else {
-      super.visitMoorSpecificNode(e, arg);
+      return super.visitMoorSpecificNode(e, arg);
     }
   }
 }

sqlparser/lib/src/analysis/steps/prepare_ast.dart

@@ -172,6 +172,12 @@ class AstPreparingVisitor extends RecursiveVisitor<void, void> {
 
   @override
   void visitNestedQueryVariable(NestedQueryVariable e, void arg) {
+    assert(
+      false,
+      'This should be unreachable, because NestedQueryVariables are only'
+      'introduced later in the NestedQueryResolver',
+    );
+
     _foundVariables.add(e);
     visitChildren(e, arg);
   }