Don't generate variables in `CREATE TABLE` (#1936)

drift/lib/src/runtime/query_builder/migration.dart

@@ -102,8 +102,8 @@ class Migrator {
     }
   }
 
-  GenerationContext _createContext() {
-    return GenerationContext.fromDb(_db);
+  GenerationContext _createContext({bool supportsVariables = false}) {
+    return GenerationContext.fromDb(_db, supportsVariables: supportsVariables);
   }
 
   /// Creates the given table if it doesn't exist
@@ -197,7 +197,7 @@ class Migrator {
       await createTable(temporaryTable);
 
       // Step 5: Transfer old content into the new table
-      final context = _createContext();
+      final context = _createContext(supportsVariables: true);
       final expressionsForSelect = <Expression>[];
 
       context.buffer.write('INSERT INTO $temporaryName (');

drift/test/database/statements/schema_test.dart

@@ -187,6 +187,28 @@ void main() {
     verify(executor.transactions.runCustom(any, any));
     verifyNever(executor.runCustom(any, any));
   });
+
+  test('removes variables in `CREATE TABLE` statements', () async {
+    final executor = MockExecutor();
+    final db = _DefaultDb(executor);
+
+    late GeneratedColumn<int> column;
+    column = GeneratedColumn<int>(
+      'foo',
+      'foo',
+      true,
+      type: DriftSqlType.int,
+      check: () => column.isSmallerThan(const Variable(3)),
+    );
+    final table = CustomTable('foo', db, [column]);
+
+    await db.createMigrator().createTable(table);
+    await db.close();
+
+    // This should not attempt to generate a parameter (`?`)
+    // https://github.com/simolus3/drift/discussions/1936
+    verify(executor.runCustom(argThat(contains('CHECK(foo < 3)')), []));
+  });
 }
 
 class _DefaultDb extends GeneratedDatabase {

drift/test/test_utils/test_utils.dart

@@ -1,5 +1,33 @@
+import 'package:drift/drift.dart';
+
 export 'database_stub.dart'
     if (dart.library.ffi) 'database_vm.dart'
     if (dart.library.js) 'database_web.dart';
 export 'matchers.dart';
 export 'mocks.dart';
+
+class CustomTable extends Table with TableInfo<CustomTable, Null> {
+  @override
+  final String actualTableName;
+  @override
+  final DatabaseConnectionUser attachedDatabase;
+  final List<GeneratedColumn<Object>> columns;
+  final String? _alias;
+
+  CustomTable(this.actualTableName, this.attachedDatabase, this.columns,
+      [this._alias]);
+
+  @override
+  List<GeneratedColumn<Object>> get $columns => columns;
+
+  @override
+  String get aliasedName => _alias ?? actualTableName;
+
+  @override
+  CustomTable createAlias(String alias) {
+    return CustomTable(actualTableName, attachedDatabase, columns, alias);
+  }
+
+  @override
+  Null map(Map<String, dynamic> data, {String? tablePrefix}) => null;
+}