Add Migrator.renameTable (#956)

moor/CHANGELOG.md

@@ -7,6 +7,7 @@
 - Added extensions for `isNull` and `isNotNull`
 - Support creating a `VmDatabase` from a raw sqlite3 `Database` via `VmDatabase.opened`
 - New `named_parameters` build option to generate named parameters for named variables in moor files
+- Added `Migrator.renameTable` to rename tables
 
 ## 3.4.0
 

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

@@ -367,6 +367,19 @@ class Migrator {
     return _issueCustomQuery(context.sql);
   }
 
+  /// Changes the [table] name from [oldName] to the current
+  /// [TableInfo.actualTableName].
+  ///
+  /// After renaming a table in moor or Dart and re-running the generator, you
+  /// can use [renameTable] in a migration step to rename the table in existing
+  /// databases.
+  Future<void> renameTable(TableInfo table, String oldName) async {
+    final context = _createContext();
+    context.buffer.write('ALTER TABLE ${escapeIfNeeded(oldName)} '
+        'RENAME TO ${escapeIfNeeded(table.actualTableName)};');
+    return _issueCustomQuery(context.sql);
+  }
+
   /// Executes the custom query.
   @Deprecated('Use customStatement in the database class')
   Future<void> issueCustomQuery(String sql, [List<dynamic>? args]) {

moor/test/integration_tests/migrations_integration_test.dart

@@ -104,6 +104,36 @@ void main() {
     expect(item.category, isNull);
   });
 
+  test('rename tables', () async {
+    // Create todos table with old name
+    final executor = VmDatabase.memory(setup: (db) {
+      db.execute('''
+        CREATE TABLE todos_old_name (
+          id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
+          title TEXT NOT NULL,
+          content TEXT NOT NULL,
+          target_date INTEGER NOT NULL,
+          category INTEGER NULL
+        );
+      ''');
+
+      db.execute('INSERT INTO todos_old_name (title, content, target_date) '
+          "VALUES ('title', 'content', 0)");
+    });
+
+    final db = TodoDb(executor);
+    db.migration = MigrationStrategy(
+      onCreate: (m) async {
+        await m.renameTable(db.todosTable, 'todos_old_name');
+      },
+    );
+
+    // basic check to ensure we can query the table by its new name and that
+    // we have all the necessary data.
+    final entry = await db.select(db.todosTable).getSingle();
+    expect(entry.title, 'title');
+  });
+
   test('add columns with default value', () async {
     final executor = VmDatabase.memory(setup: (db) {
       // Create todos table without content column