diff --git a/angel_orm/lib/angel_orm.dart b/angel_orm/lib/angel_orm.dart
index b7931d80..91952278 100644
--- a/angel_orm/lib/angel_orm.dart
+++ b/angel_orm/lib/angel_orm.dart
@@ -1,5 +1,15 @@
 export 'src/annotations.dart';
 export 'src/builder.dart';
+export 'src/join_builder.dart';
+export 'src/join_on.dart';
+export 'src/map_query_values.dart';
 export 'src/migration.dart';
-export 'src/relations.dart';
+export 'src/order_by.dart';
+export 'src/query_base.dart';
+export 'src/query_executor.dart';
+export 'src/query_values.dart';
+export 'src/query_where.dart';
 export 'src/query.dart';
+export 'src/relations.dart';
+export 'src/union.dart';
+export 'src/util.dart';
diff --git a/angel_orm/lib/src/builder.dart b/angel_orm/lib/src/builder.dart
index eac463d5..aaca4914 100644
--- a/angel_orm/lib/src/builder.dart
+++ b/angel_orm/lib/src/builder.dart
@@ -1,9 +1,9 @@
 import 'dart:convert';
-
 import 'package:charcode/ascii.dart';
 import 'package:intl/intl.dart' show DateFormat;
 import 'package:string_scanner/string_scanner.dart';
 import 'query.dart';
+import 'util.dart';
 
 final DateFormat dateYmd = DateFormat('yyyy-MM-dd');
 final DateFormat dateYmdHms = DateFormat('yyyy-MM-dd HH:mm:ss');
diff --git a/angel_orm/lib/src/join_builder.dart b/angel_orm/lib/src/join_builder.dart
new file mode 100644
index 00000000..5b591de6
--- /dev/null
+++ b/angel_orm/lib/src/join_builder.dart
@@ -0,0 +1,58 @@
+import 'annotations.dart';
+import 'query.dart';
+
+/// Builds a SQL `JOIN` query.
+class JoinBuilder {
+  final JoinType type;
+  final Query from;
+  final String to, key, value, op, alias;
+  final List<String> additionalFields;
+
+  JoinBuilder(this.type, this.from, this.to, this.key, this.value,
+      {this.op = '=', this.alias, this.additionalFields = const []}) {
+    assert(to != null,
+        'computation of this join threw an error, and returned null.');
+  }
+
+  String get fieldName {
+    var right = '$to.$value';
+    if (alias != null) right = '$alias.$value';
+    return right;
+  }
+
+  String nameFor(String name) {
+    var right = '$to.$name';
+    if (alias != null) right = '$alias.$name';
+    return right;
+  }
+
+  String compile(Set<String> trampoline) {
+    if (to == null) return null;
+    var b = StringBuffer();
+    var left = '${from.tableName}.$key';
+    var right = fieldName;
+
+    switch (type) {
+      case JoinType.inner:
+        b.write(' INNER JOIN');
+        break;
+      case JoinType.left:
+        b.write(' LEFT JOIN');
+        break;
+      case JoinType.right:
+        b.write(' RIGHT JOIN');
+        break;
+      case JoinType.full:
+        b.write(' FULL OUTER JOIN');
+        break;
+      case JoinType.self:
+        b.write(' SELF JOIN');
+        break;
+    }
+
+    b.write(' $to');
+    if (alias != null) b.write(' $alias');
+    b.write(' ON $left$op$right');
+    return b.toString();
+  }
+}
\ No newline at end of file
diff --git a/angel_orm/lib/src/join_on.dart b/angel_orm/lib/src/join_on.dart
new file mode 100644
index 00000000..acf3ee11
--- /dev/null
+++ b/angel_orm/lib/src/join_on.dart
@@ -0,0 +1,8 @@
+import 'builder.dart';
+
+class JoinOn {
+  final SqlExpressionBuilder key;
+  final SqlExpressionBuilder value;
+
+  JoinOn(this.key, this.value);
+}
\ No newline at end of file
diff --git a/angel_orm/lib/src/map_query_values.dart b/angel_orm/lib/src/map_query_values.dart
new file mode 100644
index 00000000..e69de29b
diff --git a/angel_orm/lib/src/order_by.dart b/angel_orm/lib/src/order_by.dart
new file mode 100644
index 00000000..4501cf45
--- /dev/null
+++ b/angel_orm/lib/src/order_by.dart
@@ -0,0 +1,8 @@
+class OrderBy {
+  final String key;
+  final bool descending;
+
+  const OrderBy(this.key, {this.descending = false});
+
+  String compile() => descending ? '$key DESC' : '$key ASC';
+}
diff --git a/angel_orm/lib/src/query.dart b/angel_orm/lib/src/query.dart
index 481f5702..5427ef18 100644
--- a/angel_orm/lib/src/query.dart
+++ b/angel_orm/lib/src/query.dart
@@ -1,115 +1,11 @@
 import 'dart:async';
-import 'package:charcode/ascii.dart';
 import 'annotations.dart';
-import 'builder.dart';
-
-bool isAscii(int ch) => ch >= $nul && ch <= $del;
-
-/// A base class for objects that compile to SQL queries, typically within an ORM.
-abstract class QueryBase<T> {
-  /// Casts to perform when querying the database.
-  Map<String, String> get casts => {};
-
-  /// Values to insert into a prepared statement.
-  final Map<String, dynamic> substitutionValues = {};
-
-  /// The table against which to execute this query.
-  String get tableName;
-
-  /// The list of fields returned by this query.
-  ///
-  /// If it's `null`, then this query will perform a `SELECT *`.
-  List<String> get fields;
-
-  /// A String of all [fields], joined by a comma (`,`).
-  String get fieldSet => fields.map((k) {
-        var cast = casts[k];
-        return cast == null ? k : 'CAST ($k AS $cast)';
-      }).join(', ');
-
-  String compile(Set<String> trampoline,
-      {bool includeTableName = false, String preamble, bool withFields = true});
-
-  T deserialize(List row);
-
-  Future<List<T>> get(QueryExecutor executor) async {
-    var sql = compile(Set());
-    return executor
-        .query(tableName, sql, substitutionValues)
-        .then((it) => it.map(deserialize).toList());
-  }
-
-  Future<T> getOne(QueryExecutor executor) {
-    return get(executor).then((it) => it.isEmpty ? null : it.first);
-  }
-
-  Union<T> union(QueryBase<T> other) {
-    return Union(this, other);
-  }
-
-  Union<T> unionAll(QueryBase<T> other) {
-    return Union(this, other, all: true);
-  }
-}
-
-class OrderBy {
-  final String key;
-  final bool descending;
-
-  const OrderBy(this.key, {this.descending = false});
-
-  String compile() => descending ? '$key DESC' : '$key ASC';
-}
-
-/// The ORM prefers using substitution values, which allow for prepared queries,
-/// and prevent SQL injection attacks.
-@deprecated
-String toSql(Object obj, {bool withQuotes = true}) {
-  if (obj is DateTime) {
-    return withQuotes ? "'${dateYmdHms.format(obj)}'" : dateYmdHms.format(obj);
-  } else if (obj is bool) {
-    return obj ? 'TRUE' : 'FALSE';
-  } else if (obj == null) {
-    return 'NULL';
-  } else if (obj is String) {
-    var b = StringBuffer();
-    var escaped = false;
-    var it = obj.runes.iterator;
-
-    while (it.moveNext()) {
-      if (it.current == $nul) {
-        continue; // Skip null byte
-      } else if (it.current == $single_quote) {
-        escaped = true;
-        b.write('\\x');
-        b.write(it.current.toRadixString(16).padLeft(2, '0'));
-      } else if (isAscii(it.current)) {
-        b.writeCharCode(it.current);
-      } else if (it.currentSize == 1) {
-        escaped = true;
-        b.write('\\u');
-        b.write(it.current.toRadixString(16).padLeft(4, '0'));
-      } else if (it.currentSize == 2) {
-        escaped = true;
-        b.write('\\U');
-        b.write(it.current.toRadixString(16).padLeft(8, '0'));
-      } else {
-        throw UnsupportedError(
-            'toSql() cannot encode a rune of size (${it.currentSize})');
-      }
-    }
-
-    if (!withQuotes) {
-      return b.toString();
-    } else if (escaped) {
-      return "E'$b'";
-    } else {
-      return "'$b'";
-    }
-  } else {
-    return obj.toString();
-  }
-}
+import 'join_builder.dart';
+import 'order_by.dart';
+import 'query_base.dart';
+import 'query_executor.dart';
+import 'query_values.dart';
+import 'query_where.dart';
 
 /// A SQL `SELECT` query builder.
 abstract class Query<T, Where extends QueryWhere> extends QueryBase<T> {
@@ -424,241 +320,3 @@ abstract class Query<T, Where extends QueryWhere> extends QueryBase<T> {
     return update(executor).then((it) => it.isEmpty ? null : it.first);
   }
 }
-
-abstract class QueryValues {
-  Map<String, String> get casts => {};
-
-  Map<String, dynamic> toMap();
-
-  String applyCast(String name, String sub) {
-    if (casts.containsKey(name)) {
-      var type = casts[name];
-      return 'CAST ($sub as $type)';
-    } else {
-      return sub;
-    }
-  }
-
-  String compileInsert(Query query, String tableName) {
-    var data = Map<String, dynamic>.from(toMap());
-    var keys = data.keys.toList();
-    keys.where((k) => !query.fields.contains(k)).forEach(data.remove);
-    if (data.isEmpty) return null;
-
-    var fieldSet = data.keys.join(', ');
-    var b = StringBuffer('INSERT INTO $tableName ($fieldSet) VALUES (');
-    int i = 0;
-
-    for (var entry in data.entries) {
-      if (i++ > 0) b.write(', ');
-
-      var name = query.reserveName(entry.key);
-      var s = applyCast(entry.key, '@$name');
-      query.substitutionValues[name] = entry.value;
-      b.write(s);
-    }
-
-    b.write(')');
-    return b.toString();
-  }
-
-  String compileForUpdate(Query query) {
-    var data = toMap();
-    if (data.isEmpty) return null;
-    var b = StringBuffer('SET');
-    int i = 0;
-
-    for (var entry in data.entries) {
-      if (i++ > 0) b.write(',');
-      b.write(' ');
-      b.write(entry.key);
-      b.write('=');
-
-      var name = query.reserveName(entry.key);
-      var s = applyCast(entry.key, '@$name');
-      query.substitutionValues[name] = entry.value;
-      b.write(s);
-    }
-    return b.toString();
-  }
-}
-
-/// A [QueryValues] implementation that simply writes to a [Map].
-class MapQueryValues extends QueryValues {
-  final Map<String, dynamic> values = {};
-
-  @override
-  Map<String, dynamic> toMap() => values;
-}
-
-/// Builds a SQL `WHERE` clause.
-abstract class QueryWhere {
-  final Set<QueryWhere> _and = Set();
-  final Set<QueryWhere> _not = Set();
-  final Set<QueryWhere> _or = Set();
-
-  Iterable<SqlExpressionBuilder> get expressionBuilders;
-
-  void and(QueryWhere other) {
-    _and.add(other);
-  }
-
-  void not(QueryWhere other) {
-    _not.add(other);
-  }
-
-  void or(QueryWhere other) {
-    _or.add(other);
-  }
-
-  String compile({String tableName}) {
-    var b = StringBuffer();
-    int i = 0;
-
-    for (var builder in expressionBuilders) {
-      var key = builder.columnName;
-      if (tableName != null) key = '$tableName.$key';
-      if (builder.hasValue) {
-        if (i++ > 0) b.write(' AND ');
-        if (builder is DateTimeSqlExpressionBuilder ||
-            (builder is JsonSqlExpressionBuilder && builder.hasRaw)) {
-          if (tableName != null) b.write('$tableName.');
-          b.write(builder.compile());
-        } else {
-          b.write('$key ${builder.compile()}');
-        }
-      }
-    }
-
-    for (var other in _and) {
-      var sql = other.compile();
-      if (sql.isNotEmpty) b.write(' AND $sql');
-    }
-
-    for (var other in _not) {
-      var sql = other.compile();
-      if (sql.isNotEmpty) b.write(' NOT $sql');
-    }
-
-    for (var other in _or) {
-      var sql = other.compile();
-      if (sql.isNotEmpty) b.write(' OR $sql');
-    }
-
-    return b.toString();
-  }
-}
-
-/// Represents the `UNION` of two subqueries.
-class Union<T> extends QueryBase<T> {
-  /// The subject(s) of this binary operation.
-  final QueryBase<T> left, right;
-
-  /// Whether this is a `UNION ALL` operation.
-  final bool all;
-
-  @override
-  final String tableName;
-
-  Union(this.left, this.right, {this.all = false, String tableName})
-      : this.tableName = tableName ?? left.tableName {
-    substitutionValues
-      ..addAll(left.substitutionValues)
-      ..addAll(right.substitutionValues);
-  }
-
-  @override
-  List<String> get fields => left.fields;
-
-  @override
-  T deserialize(List row) => left.deserialize(row);
-
-  @override
-  String compile(Set<String> trampoline,
-      {bool includeTableName = false,
-      String preamble,
-      bool withFields = true}) {
-    var selector = all == true ? 'UNION ALL' : 'UNION';
-    var t1 = Set<String>.from(trampoline);
-    var t2 = Set<String>.from(trampoline);
-    return '(${left.compile(t1, includeTableName: includeTableName)}) $selector (${right.compile(t2, includeTableName: includeTableName)})';
-  }
-}
-
-/// Builds a SQL `JOIN` query.
-class JoinBuilder {
-  final JoinType type;
-  final Query from;
-  final String to, key, value, op, alias;
-  final List<String> additionalFields;
-
-  JoinBuilder(this.type, this.from, this.to, this.key, this.value,
-      {this.op = '=', this.alias, this.additionalFields = const []}) {
-    assert(to != null,
-        'computation of this join threw an error, and returned null.');
-  }
-
-  String get fieldName {
-    var right = '$to.$value';
-    if (alias != null) right = '$alias.$value';
-    return right;
-  }
-
-  String nameFor(String name) {
-    var right = '$to.$name';
-    if (alias != null) right = '$alias.$name';
-    return right;
-  }
-
-  String compile(Set<String> trampoline) {
-    if (to == null) return null;
-    var b = StringBuffer();
-    var left = '${from.tableName}.$key';
-    var right = fieldName;
-
-    switch (type) {
-      case JoinType.inner:
-        b.write(' INNER JOIN');
-        break;
-      case JoinType.left:
-        b.write(' LEFT JOIN');
-        break;
-      case JoinType.right:
-        b.write(' RIGHT JOIN');
-        break;
-      case JoinType.full:
-        b.write(' FULL OUTER JOIN');
-        break;
-      case JoinType.self:
-        b.write(' SELF JOIN');
-        break;
-    }
-
-    b.write(' $to');
-    if (alias != null) b.write(' $alias');
-    b.write(' ON $left$op$right');
-    return b.toString();
-  }
-}
-
-class JoinOn {
-  final SqlExpressionBuilder key;
-  final SqlExpressionBuilder value;
-
-  JoinOn(this.key, this.value);
-}
-
-/// An abstract interface that performs queries.
-///
-/// This class should be implemented.
-abstract class QueryExecutor {
-  const QueryExecutor();
-
-  /// Executes a single query.
-  Future<List<List>> query(
-      String tableName, String query, Map<String, dynamic> substitutionValues,
-      [List<String> returningFields]);
-
-  /// Begins a database transaction.
-  Future<T> transaction<T>(FutureOr<T> f());
-}
diff --git a/angel_orm/lib/src/query_base.dart b/angel_orm/lib/src/query_base.dart
new file mode 100644
index 00000000..8e378636
--- /dev/null
+++ b/angel_orm/lib/src/query_base.dart
@@ -0,0 +1,50 @@
+import 'dart:async';
+import 'query_executor.dart';
+import 'union.dart';
+
+/// A base class for objects that compile to SQL queries, typically within an ORM.
+abstract class QueryBase<T> {
+  /// Casts to perform when querying the database.
+  Map<String, String> get casts => {};
+
+  /// Values to insert into a prepared statement.
+  final Map<String, dynamic> substitutionValues = {};
+
+  /// The table against which to execute this query.
+  String get tableName;
+
+  /// The list of fields returned by this query.
+  ///
+  /// If it's `null`, then this query will perform a `SELECT *`.
+  List<String> get fields;
+
+  /// A String of all [fields], joined by a comma (`,`).
+  String get fieldSet => fields.map((k) {
+        var cast = casts[k];
+        return cast == null ? k : 'CAST ($k AS $cast)';
+      }).join(', ');
+
+  String compile(Set<String> trampoline,
+      {bool includeTableName = false, String preamble, bool withFields = true});
+
+  T deserialize(List row);
+
+  Future<List<T>> get(QueryExecutor executor) async {
+    var sql = compile(Set());
+    return executor
+        .query(tableName, sql, substitutionValues)
+        .then((it) => it.map(deserialize).toList());
+  }
+
+  Future<T> getOne(QueryExecutor executor) {
+    return get(executor).then((it) => it.isEmpty ? null : it.first);
+  }
+
+  Union<T> union(QueryBase<T> other) {
+    return Union(this, other);
+  }
+
+  Union<T> unionAll(QueryBase<T> other) {
+    return Union(this, other, all: true);
+  }
+}
diff --git a/angel_orm/lib/src/query_executor.dart b/angel_orm/lib/src/query_executor.dart
new file mode 100644
index 00000000..558a4d9d
--- /dev/null
+++ b/angel_orm/lib/src/query_executor.dart
@@ -0,0 +1,16 @@
+import 'dart:async';
+
+/// An abstract interface that performs queries.
+///
+/// This class should be implemented.
+abstract class QueryExecutor {
+  const QueryExecutor();
+
+  /// Executes a single query.
+  Future<List<List>> query(
+      String tableName, String query, Map<String, dynamic> substitutionValues,
+      [List<String> returningFields]);
+
+  /// Begins a database transaction.
+  Future<T> transaction<T>(FutureOr<T> f());
+}
diff --git a/angel_orm/lib/src/query_values.dart b/angel_orm/lib/src/query_values.dart
new file mode 100644
index 00000000..d576060b
--- /dev/null
+++ b/angel_orm/lib/src/query_values.dart
@@ -0,0 +1,67 @@
+import 'query.dart';
+
+abstract class QueryValues {
+  Map<String, String> get casts => {};
+
+  Map<String, dynamic> toMap();
+
+  String applyCast(String name, String sub) {
+    if (casts.containsKey(name)) {
+      var type = casts[name];
+      return 'CAST ($sub as $type)';
+    } else {
+      return sub;
+    }
+  }
+
+  String compileInsert(Query query, String tableName) {
+    var data = Map<String, dynamic>.from(toMap());
+    var keys = data.keys.toList();
+    keys.where((k) => !query.fields.contains(k)).forEach(data.remove);
+    if (data.isEmpty) return null;
+
+    var fieldSet = data.keys.join(', ');
+    var b = StringBuffer('INSERT INTO $tableName ($fieldSet) VALUES (');
+    int i = 0;
+
+    for (var entry in data.entries) {
+      if (i++ > 0) b.write(', ');
+
+      var name = query.reserveName(entry.key);
+      var s = applyCast(entry.key, '@$name');
+      query.substitutionValues[name] = entry.value;
+      b.write(s);
+    }
+
+    b.write(')');
+    return b.toString();
+  }
+
+  String compileForUpdate(Query query) {
+    var data = toMap();
+    if (data.isEmpty) return null;
+    var b = StringBuffer('SET');
+    int i = 0;
+
+    for (var entry in data.entries) {
+      if (i++ > 0) b.write(',');
+      b.write(' ');
+      b.write(entry.key);
+      b.write('=');
+
+      var name = query.reserveName(entry.key);
+      var s = applyCast(entry.key, '@$name');
+      query.substitutionValues[name] = entry.value;
+      b.write(s);
+    }
+    return b.toString();
+  }
+}
+
+/// A [QueryValues] implementation that simply writes to a [Map].
+class MapQueryValues extends QueryValues {
+  final Map<String, dynamic> values = {};
+
+  @override
+  Map<String, dynamic> toMap() => values;
+}
diff --git a/angel_orm/lib/src/query_where.dart b/angel_orm/lib/src/query_where.dart
new file mode 100644
index 00000000..4006b170
--- /dev/null
+++ b/angel_orm/lib/src/query_where.dart
@@ -0,0 +1,59 @@
+import 'builder.dart';
+
+/// Builds a SQL `WHERE` clause.
+abstract class QueryWhere {
+  final Set<QueryWhere> _and = Set();
+  final Set<QueryWhere> _not = Set();
+  final Set<QueryWhere> _or = Set();
+
+  Iterable<SqlExpressionBuilder> get expressionBuilders;
+
+  void and(QueryWhere other) {
+    _and.add(other);
+  }
+
+  void not(QueryWhere other) {
+    _not.add(other);
+  }
+
+  void or(QueryWhere other) {
+    _or.add(other);
+  }
+
+  String compile({String tableName}) {
+    var b = StringBuffer();
+    int i = 0;
+
+    for (var builder in expressionBuilders) {
+      var key = builder.columnName;
+      if (tableName != null) key = '$tableName.$key';
+      if (builder.hasValue) {
+        if (i++ > 0) b.write(' AND ');
+        if (builder is DateTimeSqlExpressionBuilder ||
+            (builder is JsonSqlExpressionBuilder && builder.hasRaw)) {
+          if (tableName != null) b.write('$tableName.');
+          b.write(builder.compile());
+        } else {
+          b.write('$key ${builder.compile()}');
+        }
+      }
+    }
+
+    for (var other in _and) {
+      var sql = other.compile();
+      if (sql.isNotEmpty) b.write(' AND $sql');
+    }
+
+    for (var other in _not) {
+      var sql = other.compile();
+      if (sql.isNotEmpty) b.write(' NOT $sql');
+    }
+
+    for (var other in _or) {
+      var sql = other.compile();
+      if (sql.isNotEmpty) b.write(' OR $sql');
+    }
+
+    return b.toString();
+  }
+}
diff --git a/angel_orm/lib/src/union.dart b/angel_orm/lib/src/union.dart
new file mode 100644
index 00000000..048ebf31
--- /dev/null
+++ b/angel_orm/lib/src/union.dart
@@ -0,0 +1,37 @@
+import 'query_base.dart';
+
+/// Represents the `UNION` of two subqueries.
+class Union<T> extends QueryBase<T> {
+  /// The subject(s) of this binary operation.
+  final QueryBase<T> left, right;
+
+  /// Whether this is a `UNION ALL` operation.
+  final bool all;
+
+  @override
+  final String tableName;
+
+  Union(this.left, this.right, {this.all = false, String tableName})
+      : this.tableName = tableName ?? left.tableName {
+    substitutionValues
+      ..addAll(left.substitutionValues)
+      ..addAll(right.substitutionValues);
+  }
+
+  @override
+  List<String> get fields => left.fields;
+
+  @override
+  T deserialize(List row) => left.deserialize(row);
+
+  @override
+  String compile(Set<String> trampoline,
+      {bool includeTableName = false,
+      String preamble,
+      bool withFields = true}) {
+    var selector = all == true ? 'UNION ALL' : 'UNION';
+    var t1 = Set<String>.from(trampoline);
+    var t2 = Set<String>.from(trampoline);
+    return '(${left.compile(t1, includeTableName: includeTableName)}) $selector (${right.compile(t2, includeTableName: includeTableName)})';
+  }
+}
diff --git a/angel_orm/lib/src/util.dart b/angel_orm/lib/src/util.dart
new file mode 100644
index 00000000..cbe814ce
--- /dev/null
+++ b/angel_orm/lib/src/util.dart
@@ -0,0 +1,57 @@
+import 'dart:async';
+import 'package:charcode/ascii.dart';
+import 'annotations.dart';
+import 'builder.dart';
+import 'query_base.dart';
+
+bool isAscii(int ch) => ch >= $nul && ch <= $del;
+
+/// The ORM prefers using substitution values, which allow for prepared queries,
+/// and prevent SQL injection attacks.
+@deprecated
+String toSql(Object obj, {bool withQuotes = true}) {
+  if (obj is DateTime) {
+    return withQuotes ? "'${dateYmdHms.format(obj)}'" : dateYmdHms.format(obj);
+  } else if (obj is bool) {
+    return obj ? 'TRUE' : 'FALSE';
+  } else if (obj == null) {
+    return 'NULL';
+  } else if (obj is String) {
+    var b = StringBuffer();
+    var escaped = false;
+    var it = obj.runes.iterator;
+
+    while (it.moveNext()) {
+      if (it.current == $nul) {
+        continue; // Skip null byte
+      } else if (it.current == $single_quote) {
+        escaped = true;
+        b.write('\\x');
+        b.write(it.current.toRadixString(16).padLeft(2, '0'));
+      } else if (isAscii(it.current)) {
+        b.writeCharCode(it.current);
+      } else if (it.currentSize == 1) {
+        escaped = true;
+        b.write('\\u');
+        b.write(it.current.toRadixString(16).padLeft(4, '0'));
+      } else if (it.currentSize == 2) {
+        escaped = true;
+        b.write('\\U');
+        b.write(it.current.toRadixString(16).padLeft(8, '0'));
+      } else {
+        throw UnsupportedError(
+            'toSql() cannot encode a rune of size (${it.currentSize})');
+      }
+    }
+
+    if (!withQuotes) {
+      return b.toString();
+    } else if (escaped) {
+      return "E'$b'";
+    } else {
+      return "'$b'";
+    }
+  } else {
+    return obj.toString();
+  }
+}