diff --git a/framework/yii/test/DbFixtureManager.php b/framework/yii/test/DbFixtureManager.php
new file mode 100644
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--- /dev/null
+++ b/framework/yii/test/DbFixtureManager.php
@@ -0,0 +1,219 @@
+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\test;
+
+use Yii;
+use yii\base\Component;
+use yii\base\InvalidConfigException;
+use yii\db\ActiveRecord;
+use yii\db\Connection;
+
+/**
+ * DbFixtureManager manages database fixtures during tests.
+ *
+ * A fixture represents a list of rows for a specific table. For a test method,
+ * using a fixture means that at the beginning of the method, the table has and only
+ * has the rows that are given in the fixture. Therefore, the table's state is
+ * predictable.
+ *
+ * A fixture is represented as a PHP script whose name (without suffix) is the
+ * same as the table name (if schema name is needed, it should be prefixed to
+ * the table name). The PHP script returns an array representing a list of table
+ * rows. Each row is an associative array of column values indexed by column names.
+ *
+ * Fixtures must be stored under the [[basePath]] directory. The directory
+ * may contain a file named `init.php` which will be executed before any fixture is loaded.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @since 2.0
+ */
+class DbFixtureManager extends Component
+{
+	/**
+	 * @var string the init script file that should be executed before running each test.
+	 * This should be a path relative to [[basePath]].
+	 */
+	public $initScript = 'init.php';
+	/**
+	 * @var string the base path containing all fixtures. This can be either a directory path or path alias.
+	 */
+	public $basePath = '@app/tests/fixtures';
+	/**
+	 * @var Connection|string the DB connection object or the application component ID of the DB connection.
+	 * After the DbFixtureManager object is created, if you want to change this property, you should only assign it
+	 * with a DB connection object.
+	 */
+	public $db = 'db';
+	/**
+	 * @var array list of database schemas that the test tables may reside in. Defaults to
+	 * array(''), meaning using the default schema (an empty string refers to the
+	 * default schema). This property is mainly used when turning on and off integrity checks
+	 * so that fixture data can be populated into the database without causing problem.
+	 */
+	public $schemas = [''];
+
+	private $_rows; // fixture name, row alias => row
+	private $_models; // fixture name, row alias => record (or class name)
+	private $_modelClasses;
+
+
+	/**
+	 * Loads the specified fixtures.
+	 *
+	 * This method does the following things to load the fixtures:
+	 *
+	 * - Run [[initScript]] if any.
+	 * - Clean up data and models loaded in memory previously.
+	 * - Load each specified fixture by calling [[loadFixture()]].
+	 *
+	 * @param array $fixtures a list of fixtures (fixture name => table name or AR class name) to be loaded.
+	 * Each array element can be either a table name (with schema prefix if needed), or a fully-qualified
+	 * ActiveRecord class name (e.g. `app\models\Post`). An element can be associated with a key
+	 * which will be treated as the fixture name.
+	 * @return array the loaded fixture data (fixture name => table rows)
+	 * @throws InvalidConfigException if a model class specifying a fixture is not an ActiveRecord class.
+	 */
+	public function load(array $fixtures = [])
+	{
+		$this->basePath = Yii::getAlias($this->basePath);
+
+		if (is_string($this->db)) {
+			$this->db = Yii::$app->getComponent($this->db);
+		}
+		if (!$this->db instanceof Connection) {
+			throw new InvalidConfigException("The 'db' property must be either a DB connection instance or the application component ID of a DB connection.");
+		}
+
+		foreach ($fixtures as $name => $fixture) {
+			if (strpos($fixture, '\\') !== false) {
+				$model = new $fixture;
+				if ($model instanceof ActiveRecord) {
+					$this->_modelClasses[$name] = $fixture;
+					$fixtures[$name] = $model->getTableSchema()->name;
+				} else {
+					throw new InvalidConfigException("Fixture '$fixture' must be an ActiveRecord class.");
+				}
+			}
+		}
+
+		$this->_modelClasses = $this->_rows = $this->_models = [];
+
+		$this->checkIntegrity(false);
+
+		if (!empty($this->initScript)) {
+			$initFile = $this->basePath . '/' . $this->initScript;
+			if (is_file($initFile)) {
+				require($initFile);
+			}
+		}
+
+		foreach ($fixtures as $name => $tableName) {
+			$rows = $this->loadFixture($tableName);
+			if (is_array($rows)) {
+				$this->_rows[$name] = $rows;
+			}
+		}
+		$this->checkIntegrity(true);
+		return $this->_rows;
+	}
+
+	/**
+	 * Loads the fixture for the specified table.
+	 *
+	 * This method does the following tasks to load the fixture for a table:
+	 *
+	 * - Remove existing rows in the table.
+	 * - If there is any auto-incremental column, the corresponding sequence will be reset to 0.
+	 * - If a fixture file is found, it will be executed, and its return value will be treated
+	 *   as rows which will then be inserted into the table.
+	 *
+	 * @param string $tableName table name
+	 * @return array|boolean the loaded fixture rows indexed by row aliases (if any).
+	 * False is returned if the table does not have a fixture.
+	 * @throws InvalidConfigException if the specified table does not exist
+	 */
+	public function loadFixture($tableName)
+	{
+		$table = $this->db->getSchema()->getTableSchema($tableName);
+		if ($table === null) {
+			throw new InvalidConfigException("Table does not exist: $tableName");
+		}
+
+		$this->db->createCommand()->truncateTable($tableName);
+
+		$fileName = $this->basePath . '/' . $tableName . '.php';
+		if (!is_file($fileName)) {
+			return false;
+		}
+
+		$rows = [];
+		foreach (require($fileName) as $alias => $row) {
+			$this->db->createCommand()->insert($tableName, $row)->execute();
+			if ($table->sequenceName !== null) {
+				foreach ($table->primaryKey as $pk) {
+					if (!isset($row[$pk])) {
+						$row[$pk] = $this->db->getLastInsertID($table->sequenceName);
+						break;
+					}
+				}
+			}
+			$rows[$alias] = $row;
+		}
+
+		return $rows;
+	}
+
+	/**
+	 * Returns the fixture data rows.
+	 * The rows will have updated primary key values if the primary key is auto-incremental.
+	 * @param string $fixtureName the fixture name
+	 * @return array the fixture data rows. False is returned if there is no such fixture data.
+	 */
+	public function getRows($fixtureName)
+	{
+		return isset($this->_rows[$fixtureName]) ? $this->_rows[$fixtureName] : false;
+	}
+
+	/**
+	 * Returns the specified ActiveRecord instance in the fixture data.
+	 * @param string $fixtureName the fixture name
+	 * @param string $modelName the alias for the fixture data row
+	 * @return \yii\db\ActiveRecord the ActiveRecord instance. Null is returned if there is no such fixture row.
+	 */
+	public function getModel($fixtureName, $modelName)
+	{
+		if (!isset($this->_modelClasses[$fixtureName]) || !isset($this->_rows[$fixtureName][$modelName])) {
+			return null;
+		}
+		if (isset($this->_models[$fixtureName][$modelName])) {
+			return $this->_models[$fixtureName][$modelName];
+		}
+		$row = $this->_rows[$fixtureName][$modelName];
+		/** @var \yii\db\ActiveRecord $modelClass */
+		$modelClass = $this->_models[$fixtureName];
+		/** @var \yii\db\ActiveRecord $model */
+		$model = new $modelClass;
+		$keys = [];
+		foreach ($model->primaryKey() as $key) {
+			$keys[$key] = isset($row[$key]) ? $row[$key] : null;
+		}
+		return $this->_models[$fixtureName][$modelName] = $modelClass::find($keys);
+	}
+
+	/**
+	 * Enables or disables database integrity check.
+	 * This method may be used to temporarily turn off foreign constraints check.
+	 * @param boolean $check whether to enable database integrity check
+	 */
+	public function checkIntegrity($check)
+	{
+		foreach ($this->schemas as $schema) {
+			$this->db->createCommand()->checkIntegrity($check, $schema);
+		}
+	}
+}
diff --git a/framework/yii/test/DbTestTrait.php b/framework/yii/test/DbTestTrait.php
new file mode 100644
index 0000000..8a6dc3c
--- /dev/null
+++ b/framework/yii/test/DbTestTrait.php
@@ -0,0 +1,110 @@
+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\test;
+
+use Yii;
+
+/**
+ * DbTestTrait implements the commonly used methods for setting up and accessing fixture data.
+ *
+ * To use DbTestTrait, call the [[loadFixtures()]] method in the setup method in a test case class.
+ * The specified fixtures will be loaded and accessible through [[getFixtureData()]] and [[getFixtureModel()]].
+ *
+ * For example,
+ *
+ * ~~~
+ * use yii\test\DbTestTrait;
+ * use app\models\Post;
+ * use app\models\User;
+ *
+ * class PostTestCase extends \PHPUnit_Framework_TestCase
+ * {
+ *     use DbTestTrait;
+ *
+ *     public function setUp()
+ *     {
+ *         $this->loadFixtures([
+ *             'posts' => Post::className(),
+ *             'users' => User::className(),
+ *         ]);
+ *     }
+ * }
+ * ~~~
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @since 2.0
+ */
+trait DbTestTrait
+{
+	/**
+	 * Loads the specified fixtures.
+	 *
+	 * This method should typically be called in the setup method of test cases so that
+	 * the fixtures are loaded before running each test method.
+	 *
+	 * This method does the following things:
+	 *
+	 * - Run [[DbFixtureManager::initScript]] if it is found under [[DbFixtureManager::basePath]].
+	 * - Clean up data and models loaded in memory previously.
+	 * - Load each specified fixture:
+	 *      * Truncate the corresponding table.
+	 *      * If a fixture file named `TableName.php` is found under [[DbFixtureManager::basePath]],
+	 *        the file will be executed, and the return value will be treated as rows which will
+	 *        then be inserted into the table.
+	 *
+	 * @param array $fixtures a list of fixtures (fixture name => table name or AR class name) to be loaded.
+	 * Each array element can be either a table name (with schema prefix if needed), or a fully-qualified
+	 * ActiveRecord class name (e.g. `app\models\Post`). An element can be optionally associated with a key
+	 * which will be treated as the fixture name. For example,
+	 *
+	 * ~~~
+	 * [
+	 *     'tbl_comment',
+	 *     'users' => 'tbl_user',   // 'users' is the fixture name, 'tbl_user' is a table name
+	 *     'posts' => 'app\models\Post,  // 'app\models\Post' is a model class name
+	 * ]
+	 * ~~~
+	 *
+	 * @return array the loaded fixture data (fixture name => table rows)
+	 */
+	public function loadFixtures(array $fixtures = [])
+	{
+		return $this->getFixtureManager()->load($fixtures);
+	}
+
+	/**
+	 * Returns the DB fixture manager.
+	 * @return DbFixtureManager the DB fixture manager
+	 */
+	public function getFixtureManager()
+	{
+		return Yii::$app->getComponent('fixture');
+	}
+
+	/**
+	 * Returns the table rows of the named fixture.
+	 * @param string $fixtureName the fixture name.
+	 * @return array the named fixture table rows. False is returned if there is no such fixture data.
+	 */
+	public function getFixtureRows($fixtureName)
+	{
+		return $this->getFixtureManager()->getRows($fixtureName);
+	}
+
+	/**
+	 * Returns the named AR instance corresponding to the named fixture.
+	 * @param string $fixtureName the fixture name.
+	 * @param string $modelName the name of the fixture data row
+	 * @return \yii\db\ActiveRecord the named AR instance corresponding to the named fixture.
+	 * Null is returned if there is no such fixture or the record cannot be found.
+	 */
+	public function getFixtureModel($fixtureName, $modelName)
+	{
+		return $this->getFixtureManager()->getModel($fixtureName, $modelName);
+	}
+}