diff --git a/tests/unit/framework/db/CommandTest.php b/tests/unit/framework/db/CommandTest.php
index 52fd046..229545d 100644
--- a/tests/unit/framework/db/CommandTest.php
+++ b/tests/unit/framework/db/CommandTest.php
@@ -9,12 +9,6 @@ use yii\db\DataReader;
 
 class CommandTest extends DatabaseTestCase
 {
-	protected function setUp()
-	{
-		parent::setUp();
-		$this->mockApplication();
-	}
-
 	public function testConstruct()
 	{
 		$db = $this->getConnection(false);
diff --git a/tests/unit/framework/db/ConnectionTest.php b/tests/unit/framework/db/ConnectionTest.php
index 42b470b..f2895f1 100644
--- a/tests/unit/framework/db/ConnectionTest.php
+++ b/tests/unit/framework/db/ConnectionTest.php
@@ -6,12 +6,6 @@ use yii\db\Connection;
 
 class ConnectionTest extends DatabaseTestCase
 {
-	protected function setUp()
-	{
-		parent::setUp();
-		$this->mockApplication();
-	}
-
 	public function testConstruct()
 	{
 		$connection = $this->getConnection(false);
diff --git a/tests/unit/framework/db/DatabaseTestCase.php b/tests/unit/framework/db/DatabaseTestCase.php
index 1dd8cfc..d8d2916 100644
--- a/tests/unit/framework/db/DatabaseTestCase.php
+++ b/tests/unit/framework/db/DatabaseTestCase.php
@@ -16,7 +16,6 @@ abstract class DatabaseTestCase extends TestCase
 	protected function setUp()
 	{
 		parent::setUp();
-		$this->mockApplication();
 		$databases = $this->getParam('databases');
 		$this->database = $databases[$this->driverName];
 		$pdo_database = 'pdo_'.$this->driverName;
@@ -24,6 +23,7 @@ abstract class DatabaseTestCase extends TestCase
 		if (!extension_loaded('pdo') || !extension_loaded($pdo_database)) {
 			$this->markTestSkipped('pdo and pdo_'.$pdo_database.' extension are required.');
 		}
+		$this->mockApplication();
 	}
 
 	protected function tearDown()
@@ -31,6 +31,7 @@ abstract class DatabaseTestCase extends TestCase
 		if ($this->db) {
 			$this->db->close();
 		}
+		$this->destroyApplication();
 	}
 
 	/**
diff --git a/tests/unit/framework/db/QueryBuilderTest.php b/tests/unit/framework/db/QueryBuilderTest.php
index 81a8156..a2815e8 100644
--- a/tests/unit/framework/db/QueryBuilderTest.php
+++ b/tests/unit/framework/db/QueryBuilderTest.php
@@ -12,12 +12,6 @@ use yii\db\cubrid\QueryBuilder as CubridQueryBuilder;
 
 class QueryBuilderTest extends DatabaseTestCase
 {
-	protected function setUp()
-	{
-		parent::setUp();
-		$this->mockApplication();
-	}
-
 	/**
 	 * @throws \Exception
 	 * @return QueryBuilder
diff --git a/tests/unit/framework/db/QueryTest.php b/tests/unit/framework/db/QueryTest.php
index 5d1f1a9..dfb6c9f 100644
--- a/tests/unit/framework/db/QueryTest.php
+++ b/tests/unit/framework/db/QueryTest.php
@@ -9,12 +9,6 @@ use yii\db\DataReader;
 
 class QueryTest extends DatabaseTestCase
 {
-	protected function setUp()
-	{
-		parent::setUp();
-		$this->mockApplication();
-	}
-
 	public function testSelect()
 	{
 		// default
diff --git a/tests/unit/framework/db/cubrid/CubridActiveRecordTest.php b/tests/unit/framework/db/cubrid/CubridActiveRecordTest.php
index b30880b..6633e11 100644
--- a/tests/unit/framework/db/cubrid/CubridActiveRecordTest.php
+++ b/tests/unit/framework/db/cubrid/CubridActiveRecordTest.php
@@ -5,9 +5,5 @@ use yiiunit\framework\db\ActiveRecordTest;
 
 class CubridActiveRecordTest extends ActiveRecordTest
 {
-	protected function setUp()
-	{
-		$this->driverName = 'cubrid';
-		parent::setUp();
-	}
+	public $driverName = 'cubrid';
 }
diff --git a/tests/unit/framework/db/cubrid/CubridCommandTest.php b/tests/unit/framework/db/cubrid/CubridCommandTest.php
index 6f10113..5fe8848 100644
--- a/tests/unit/framework/db/cubrid/CubridCommandTest.php
+++ b/tests/unit/framework/db/cubrid/CubridCommandTest.php
@@ -5,11 +5,7 @@ use yiiunit\framework\db\CommandTest;
 
 class CubridCommandTest extends CommandTest
 {
-	protected function setUp()
-	{
-		$this->driverName = 'cubrid';
-		parent::setUp();
-	}
+	public $driverName = 'cubrid';
 
 	public function testBindParamValue()
 	{
diff --git a/tests/unit/framework/db/cubrid/CubridConnectionTest.php b/tests/unit/framework/db/cubrid/CubridConnectionTest.php
index bfd2c90..6924883 100644
--- a/tests/unit/framework/db/cubrid/CubridConnectionTest.php
+++ b/tests/unit/framework/db/cubrid/CubridConnectionTest.php
@@ -5,11 +5,7 @@ use yiiunit\framework\db\ConnectionTest;
 
 class CubridConnectionTest extends ConnectionTest
 {
-	protected function setUp()
-	{
-		$this->driverName = 'cubrid';
-		parent::setUp();
-	}
+	public $driverName = 'cubrid';
 
 	public function testQuoteValue()
 	{
diff --git a/tests/unit/framework/db/cubrid/CubridQueryTest.php b/tests/unit/framework/db/cubrid/CubridQueryTest.php
index 0503fbc..2c68a35 100644
--- a/tests/unit/framework/db/cubrid/CubridQueryTest.php
+++ b/tests/unit/framework/db/cubrid/CubridQueryTest.php
@@ -5,9 +5,5 @@ use yiiunit\framework\db\QueryTest;
 
 class CubridQueryTest extends QueryTest
 {
-	protected function setUp()
-	{
-		$this->driverName = 'cubrid';
-		parent::setUp();
-	}
+	public $driverName = 'cubrid';
 }
diff --git a/tests/unit/framework/db/mssql/MssqlActiveRecordTest.php b/tests/unit/framework/db/mssql/MssqlActiveRecordTest.php
index 5647411..92e4da2 100644
--- a/tests/unit/framework/db/mssql/MssqlActiveRecordTest.php
+++ b/tests/unit/framework/db/mssql/MssqlActiveRecordTest.php
@@ -6,9 +6,5 @@ use yiiunit\framework\db\ActiveRecordTest;
 
 class MssqlActiveRecordTest extends ActiveRecordTest
 {
-	protected function setUp()
-	{
-		$this->driverName = 'sqlsrv';
-		parent::setUp();
-	}
+	protected $driverName = 'sqlsrv';
 }
diff --git a/tests/unit/framework/db/mssql/MssqlCommandTest.php b/tests/unit/framework/db/mssql/MssqlCommandTest.php
index e27fcee..1908f65 100644
--- a/tests/unit/framework/db/mssql/MssqlCommandTest.php
+++ b/tests/unit/framework/db/mssql/MssqlCommandTest.php
@@ -6,11 +6,7 @@ use yiiunit\framework\db\CommandTest;
 
 class MssqlCommandTest extends CommandTest
 {
-	public function setUp()
-	{
-		$this->driverName = 'sqlsrv';
-		parent::setUp();
-	}
+	protected $driverName = 'sqlsrv';
 
 	public function testAutoQuoting()
 	{
diff --git a/tests/unit/framework/db/mssql/MssqlConnectionTest.php b/tests/unit/framework/db/mssql/MssqlConnectionTest.php
index 7bbaae7..854c81f 100644
--- a/tests/unit/framework/db/mssql/MssqlConnectionTest.php
+++ b/tests/unit/framework/db/mssql/MssqlConnectionTest.php
@@ -6,11 +6,7 @@ use yiiunit\framework\db\ConnectionTest;
 
 class MssqlConnectionTest extends ConnectionTest
 {
-	public function setUp()
-	{
-		$this->driverName = 'sqlsrv';
-		parent::setUp();
-	}
+	protected $driverName = 'sqlsrv';
 
 	public function testQuoteValue()
 	{
diff --git a/tests/unit/framework/db/mssql/MssqlQueryTest.php b/tests/unit/framework/db/mssql/MssqlQueryTest.php
index 4f37c14..e07ac1d 100644
--- a/tests/unit/framework/db/mssql/MssqlQueryTest.php
+++ b/tests/unit/framework/db/mssql/MssqlQueryTest.php
@@ -6,9 +6,5 @@ use yiiunit\framework\db\QueryTest;
 
 class MssqlQueryTest extends QueryTest
 {
-	public function setUp()
-	{
-		$this->driverName = 'sqlsrv';
-		parent::setUp();
-	}
+	protected $driverName = 'sqlsrv';
 }
diff --git a/tests/unit/framework/db/pgsql/PostgreSQLActiveRecordTest.php b/tests/unit/framework/db/pgsql/PostgreSQLActiveRecordTest.php
index 2836223..aef09fd 100644
--- a/tests/unit/framework/db/pgsql/PostgreSQLActiveRecordTest.php
+++ b/tests/unit/framework/db/pgsql/PostgreSQLActiveRecordTest.php
@@ -6,9 +6,5 @@ use yiiunit\framework\db\ActiveRecordTest;
 
 class PostgreSQLActiveRecordTest extends ActiveRecordTest
 {
-	protected function setUp()
-	{
-		$this->driverName = 'pgsql';
-		parent::setUp();
-	}
+	protected $driverName = 'pgsql';
 }
diff --git a/tests/unit/framework/db/pgsql/PostgreSQLConnectionTest.php b/tests/unit/framework/db/pgsql/PostgreSQLConnectionTest.php
index 7ac65c5..cd76a97 100644
--- a/tests/unit/framework/db/pgsql/PostgreSQLConnectionTest.php
+++ b/tests/unit/framework/db/pgsql/PostgreSQLConnectionTest.php
@@ -5,11 +5,7 @@ use yiiunit\framework\db\ConnectionTest;
 
 class PostgreSQLConnectionTest extends ConnectionTest
 {
-	public function setUp()
-	{
-		$this->driverName = 'pgsql';
-		parent::setUp();
-	}
+	protected $driverName = 'pgsql';
 
 	public function testConnection()
 	{
diff --git a/tests/unit/framework/db/pgsql/PostgreSQLQueryBuilderTest.php b/tests/unit/framework/db/pgsql/PostgreSQLQueryBuilderTest.php
index 7c31190..bf2dd73 100644
--- a/tests/unit/framework/db/pgsql/PostgreSQLQueryBuilderTest.php
+++ b/tests/unit/framework/db/pgsql/PostgreSQLQueryBuilderTest.php
@@ -2,13 +2,11 @@
 
 namespace yiiunit\framework\db\pgsql;
 
-use yii\base\NotSupportedException;
 use yii\db\pgsql\Schema;
 use yiiunit\framework\db\QueryBuilderTest;
 
 class PostgreSQLQueryBuilderTest extends QueryBuilderTest
 {
-
 	public $driverName = 'pgsql';
 	
 	public function columnTypes()
diff --git a/tests/unit/framework/db/sqlite/SqliteActiveRecordTest.php b/tests/unit/framework/db/sqlite/SqliteActiveRecordTest.php
index 2e76162..1088280 100644
--- a/tests/unit/framework/db/sqlite/SqliteActiveRecordTest.php
+++ b/tests/unit/framework/db/sqlite/SqliteActiveRecordTest.php
@@ -5,9 +5,5 @@ use yiiunit\framework\db\ActiveRecordTest;
 
 class SqliteActiveRecordTest extends ActiveRecordTest
 {
-	protected function setUp()
-	{
-		$this->driverName = 'sqlite';
-		parent::setUp();
-	}
+	protected $driverName = 'sqlite';
 }
diff --git a/tests/unit/framework/db/sqlite/SqliteCommandTest.php b/tests/unit/framework/db/sqlite/SqliteCommandTest.php
index e330c7e..af9a323 100644
--- a/tests/unit/framework/db/sqlite/SqliteCommandTest.php
+++ b/tests/unit/framework/db/sqlite/SqliteCommandTest.php
@@ -5,11 +5,7 @@ use yiiunit\framework\db\CommandTest;
 
 class SqliteCommandTest extends CommandTest
 {
-	protected function setUp()
-	{
-		$this->driverName = 'sqlite';
-		parent::setUp();
-	}
+	protected $driverName = 'sqlite';
 
 	public function testAutoQuoting()
 	{
diff --git a/tests/unit/framework/db/sqlite/SqliteConnectionTest.php b/tests/unit/framework/db/sqlite/SqliteConnectionTest.php
index 2065200..f1d5b94 100644
--- a/tests/unit/framework/db/sqlite/SqliteConnectionTest.php
+++ b/tests/unit/framework/db/sqlite/SqliteConnectionTest.php
@@ -5,11 +5,7 @@ use yiiunit\framework\db\ConnectionTest;
 
 class SqliteConnectionTest extends ConnectionTest
 {
-	protected function setUp()
-	{
-		$this->driverName = 'sqlite';
-		parent::setUp();
-	}
+	protected $driverName = 'sqlite';
 
 	public function testConstruct()
 	{
diff --git a/tests/unit/framework/db/sqlite/SqliteQueryBuilderTest.php b/tests/unit/framework/db/sqlite/SqliteQueryBuilderTest.php
index 3291187..2e3a615 100644
--- a/tests/unit/framework/db/sqlite/SqliteQueryBuilderTest.php
+++ b/tests/unit/framework/db/sqlite/SqliteQueryBuilderTest.php
@@ -8,7 +8,7 @@ use yiiunit\framework\db\QueryBuilderTest;
 
 class SqliteQueryBuilderTest extends QueryBuilderTest
 {
-	public $driverName = 'sqlite';
+	protected $driverName = 'sqlite';
 
 	public function columnTypes()
 	{
diff --git a/tests/unit/framework/db/sqlite/SqliteQueryTest.php b/tests/unit/framework/db/sqlite/SqliteQueryTest.php
index ebbb1bb..3f112dc 100644
--- a/tests/unit/framework/db/sqlite/SqliteQueryTest.php
+++ b/tests/unit/framework/db/sqlite/SqliteQueryTest.php
@@ -5,9 +5,5 @@ use yiiunit\framework\db\QueryTest;
 
 class SqliteQueryTest extends QueryTest
 {
-	protected function setUp()
-	{
-		$this->driverName = 'sqlite';
-		parent::setUp();
-	}
+	protected $driverName = 'sqlite';
 }