diff --git a/tests/unit/data/mysql.sql b/tests/unit/data/mysql.sql
index 2e9458e..9a31083 100644
--- a/tests/unit/data/mysql.sql
+++ b/tests/unit/data/mysql.sql
@@ -100,3 +100,35 @@ INSERT INTO tbl_order_item (order_id, item_id, quantity, subtotal) VALUES (2, 4,
 INSERT INTO tbl_order_item (order_id, item_id, quantity, subtotal) VALUES (2, 5, 1, 15.0);
 INSERT INTO tbl_order_item (order_id, item_id, quantity, subtotal) VALUES (2, 3, 1, 8.0);
 INSERT INTO tbl_order_item (order_id, item_id, quantity, subtotal) VALUES (3, 2, 1, 40.0);
+
+
+/**
+ * (MySQL-)Database Schema for ExistValidatorTest
+ */
+
+DROP TABLE IF EXISTS tbl_validator_exist_main CASCADE;
+DROP TABLE IF EXISTS tbl_validator_exist_ref CASCADE;
+
+CREATE TABLE `tbl_validator_exist_main` (
+  `id`     INT(11) NOT NULL AUTO_INCREMENT,
+  `field1` VARCHAR(255),
+  PRIMARY KEY (`id`)
+) ENGINE =InnoDB  DEFAULT CHARSET =utf8;
+
+CREATE TABLE `tbl_validator_exist_ref` (
+  `id`      INT(11) NOT NULL AUTO_INCREMENT,
+  `a_field` VARCHAR(255),
+  `ref`     INT(11),
+  PRIMARY KEY (`id`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8;
+
+INSERT INTO tbl_validator_exist_main (id, field1) VALUES (1, 'just a string1');
+INSERT INTO tbl_validator_exist_main (id, field1) VALUES (2, 'just a string2');
+INSERT INTO tbl_validator_exist_main (id, field1) VALUES (3, 'just a string3');
+INSERT INTO tbl_validator_exist_main (id, field1) VALUES (4, 'just a string4');
+INSERT INTO tbl_validator_exist_ref (a_field, ref) VALUES ('ref_to_2', 2);
+INSERT INTO tbl_validator_exist_ref (a_field, ref) VALUES ('ref_to_2', 2);
+INSERT INTO tbl_validator_exist_ref (a_field, ref) VALUES ('ref_to_3', 3);
+INSERT INTO tbl_validator_exist_ref (a_field, ref) VALUES ('ref_to_4', 4);
+INSERT INTO tbl_validator_exist_ref (a_field, ref) VALUES ('ref_to_4', 4);
+INSERT INTO tbl_validator_exist_ref (a_field, ref) VALUES ('ref_to_5', 5);
diff --git a/tests/unit/data/postgres.sql b/tests/unit/data/postgres.sql
index f8fb0eb..fc306da 100644
--- a/tests/unit/data/postgres.sql
+++ b/tests/unit/data/postgres.sql
@@ -92,3 +92,32 @@ INSERT INTO tbl_order_item (order_id, item_id, quantity, subtotal) VALUES (2, 4,
 INSERT INTO tbl_order_item (order_id, item_id, quantity, subtotal) VALUES (2, 5, 1, 15.0);
 INSERT INTO tbl_order_item (order_id, item_id, quantity, subtotal) VALUES (2, 3, 1, 8.0);
 INSERT INTO tbl_order_item (order_id, item_id, quantity, subtotal) VALUES (3, 2, 1, 40.0);
+
+/**
+ * (Postgres-)Database Schema for ExistValidatorTest
+ */
+
+DROP TABLE IF EXISTS tbl_validator_exist_main CASCADE;
+DROP TABLE IF EXISTS tbl_validator_exist_ref CASCADE;
+
+CREATE TABLE tbl_validator_exist_main (
+  id integer not null primary key,
+  field1 VARCHAR(255)
+);
+
+CREATE TABLE tbl_validator_exist_ref (
+  id integer not null primary key,
+  a_field VARCHAR(255),
+  ref     integer
+);
+
+INSERT INTO tbl_validator_exist_main (id, field1) VALUES (1, 'just a string1');
+INSERT INTO tbl_validator_exist_main (id, field1) VALUES (2, 'just a string2');
+INSERT INTO tbl_validator_exist_main (id, field1) VALUES (3, 'just a string3');
+INSERT INTO tbl_validator_exist_main (id, field1) VALUES (4, 'just a string4');
+INSERT INTO tbl_validator_exist_ref (id, a_field, ref) VALUES (1, 'ref_to_2', 2);
+INSERT INTO tbl_validator_exist_ref (id, a_field, ref) VALUES (2, 'ref_to_2', 2);
+INSERT INTO tbl_validator_exist_ref (id, a_field, ref) VALUES (3, 'ref_to_3', 3);
+INSERT INTO tbl_validator_exist_ref (id, a_field, ref) VALUES (4, 'ref_to_4', 4);
+INSERT INTO tbl_validator_exist_ref (id, a_field, ref) VALUES (5, 'ref_to_4', 4);
+INSERT INTO tbl_validator_exist_ref (id, a_field, ref) VALUES (6, 'ref_to_5', 5);
\ No newline at end of file
diff --git a/tests/unit/data/sqlite.sql b/tests/unit/data/sqlite.sql
index f75bfa6..c1111da 100644
--- a/tests/unit/data/sqlite.sql
+++ b/tests/unit/data/sqlite.sql
@@ -85,4 +85,35 @@ INSERT INTO tbl_order_item (order_id, item_id, quantity, subtotal) VALUES (1, 2,
 INSERT INTO tbl_order_item (order_id, item_id, quantity, subtotal) VALUES (2, 4, 1, 10.0);
 INSERT INTO tbl_order_item (order_id, item_id, quantity, subtotal) VALUES (2, 5, 1, 15.0);
 INSERT INTO tbl_order_item (order_id, item_id, quantity, subtotal) VALUES (2, 3, 1, 8.0);
-INSERT INTO tbl_order_item (order_id, item_id, quantity, subtotal) VALUES (3, 2, 1, 40.0);
\ No newline at end of file
+INSERT INTO tbl_order_item (order_id, item_id, quantity, subtotal) VALUES (3, 2, 1, 40.0);
+
+/**
+ * (SqLite-)Database Schema for ExistValidatorTest
+ */
+
+DROP TABLE IF EXISTS tbl_validator_exist_main;
+DROP TABLE IF EXISTS tbl_validator_exist_ref;
+
+CREATE TABLE tbl_validator_exist_main (
+  id     INT(11) NOT NULL,
+  field1 VARCHAR(255),
+  PRIMARY KEY (id)
+);
+
+CREATE TABLE tbl_validator_exist_ref (
+  id      INT(11) NOT NULL,
+  a_field VARCHAR(255),
+  ref     INT(11),
+  PRIMARY KEY (id)
+);
+
+INSERT INTO tbl_validator_exist_main (id, field1) VALUES (1, 'just a string1');
+INSERT INTO tbl_validator_exist_main (id, field1) VALUES (2, 'just a string2');
+INSERT INTO tbl_validator_exist_main (id, field1) VALUES (3, 'just a string3');
+INSERT INTO tbl_validator_exist_main (id, field1) VALUES (4, 'just a string4');
+INSERT INTO tbl_validator_exist_ref (id, a_field, ref) VALUES (1, 'ref_to_2', 2);
+INSERT INTO tbl_validator_exist_ref (id, a_field, ref) VALUES (2, 'ref_to_2', 2);
+INSERT INTO tbl_validator_exist_ref (id, a_field, ref) VALUES (3, 'ref_to_3', 3);
+INSERT INTO tbl_validator_exist_ref (id, a_field, ref) VALUES (4, 'ref_to_4', 4);
+INSERT INTO tbl_validator_exist_ref (id, a_field, ref) VALUES (5, 'ref_to_4', 4);
+INSERT INTO tbl_validator_exist_ref (id, a_field, ref) VALUES (6, 'ref_to_5', 5);
\ No newline at end of file
diff --git a/tests/unit/data/validators/models/ExistValidatorMainModel.php b/tests/unit/data/validators/models/ExistValidatorMainModel.php
new file mode 100644
index 0000000..5f3ff00
--- /dev/null
+++ b/tests/unit/data/validators/models/ExistValidatorMainModel.php
@@ -0,0 +1,20 @@
+<?php
+
+namespace yiiunit\data\validators\models;
+
+
+use yii\db\ActiveRecord;
+
+class ExistValidatorMainModel extends ActiveRecord
+{
+	public $testMainVal = 1;
+	public static function tableName()
+	{
+		return 'tbl_validator_exist_main';
+	}
+
+	public function getReferences()
+	{
+		return $this->hasMany(ExistValidatorRefModel::className(), array('ref' => 'id'));
+	}
+}
\ No newline at end of file
diff --git a/tests/unit/data/validators/models/ExistValidatorRefModel.php b/tests/unit/data/validators/models/ExistValidatorRefModel.php
new file mode 100644
index 0000000..6cafa39
--- /dev/null
+++ b/tests/unit/data/validators/models/ExistValidatorRefModel.php
@@ -0,0 +1,22 @@
+<?php
+
+namespace yiiunit\data\validators\models;
+
+
+use yii\db\ActiveRecord;
+
+class ExistValidatorRefModel extends ActiveRecord
+{
+
+	public $test_val = 2;
+	public $test_val_fail = 99;
+	public static function tableName()
+	{
+		return 'tbl_validator_exist_ref';
+	}
+
+	public function getMain()
+	{
+		return $this->hasOne(ExistValidatorMainModel::className(), array('id' => 'ref'));
+	}
+}
\ No newline at end of file
diff --git a/tests/unit/framework/db/DatabaseTestCase.php b/tests/unit/framework/db/DatabaseTestCase.php
index 1fd2d56..c3d4206 100644
--- a/tests/unit/framework/db/DatabaseTestCase.php
+++ b/tests/unit/framework/db/DatabaseTestCase.php
@@ -8,6 +8,7 @@ abstract class DatabaseTestCase extends TestCase
 	protected $database;
 	protected $driverName = 'mysql';
 	protected $db;
+	protected $initializeAppWithDb = false;
 
 	protected function setUp()
 	{
@@ -18,7 +19,10 @@ abstract class DatabaseTestCase extends TestCase
 		$pdo_database = 'pdo_'.$this->driverName;
 
 		if (!extension_loaded('pdo') || !extension_loaded($pdo_database)) {
-			$this->markTestSkipped('pdo and pdo_'.$pdo_database.' extension are required.');
+			$this->markTestSkipped('pdo and '.$pdo_database.' extension are required.');
+		}
+		if ($this->initializeAppWithDb === true) {
+			\Yii::$app->setComponent('db', $this->getConnection());
 		}
 	}
 
diff --git a/tests/unit/framework/validators/ExistValidatorDriverTests/ExistValidatorPostgresTest.php b/tests/unit/framework/validators/ExistValidatorDriverTests/ExistValidatorPostgresTest.php
new file mode 100644
index 0000000..539b458
--- /dev/null
+++ b/tests/unit/framework/validators/ExistValidatorDriverTests/ExistValidatorPostgresTest.php
@@ -0,0 +1,10 @@
+<?php
+namespace yiiunit\framework\validators\ExistValidatorDriverTests;
+
+
+use yiiunit\framework\validators\ExistValidatorTest;
+
+class ExistValidatorPostgresTest extends ExistValidatorTest
+{
+	protected $driverName = 'pgsql';
+}
\ No newline at end of file
diff --git a/tests/unit/framework/validators/ExistValidatorDriverTests/ExistValidatorSQliteTest.php b/tests/unit/framework/validators/ExistValidatorDriverTests/ExistValidatorSQliteTest.php
new file mode 100644
index 0000000..cc83fd6
--- /dev/null
+++ b/tests/unit/framework/validators/ExistValidatorDriverTests/ExistValidatorSQliteTest.php
@@ -0,0 +1,10 @@
+<?php
+namespace yiiunit\framework\validators\ExistValidatorDriverTests;
+
+
+use yiiunit\framework\validators\ExistValidatorTest;
+
+class ExistValidatorSQliteTest extends ExistValidatorTest
+{
+	protected $driverName = 'sqlite';
+}
\ No newline at end of file
diff --git a/tests/unit/framework/validators/ExistValidatorTest.php b/tests/unit/framework/validators/ExistValidatorTest.php
new file mode 100644
index 0000000..6a1e5fe
--- /dev/null
+++ b/tests/unit/framework/validators/ExistValidatorTest.php
@@ -0,0 +1,94 @@
+<?php
+
+namespace yiiunit\framework\validators;
+
+
+use Yii;
+use yii\base\Exception;
+use yii\validators\ExistValidator;
+use yiiunit\data\ar\ActiveRecord;
+use yiiunit\data\validators\models\ExistValidatorMainModel;
+use yiiunit\data\validators\models\ExistValidatorRefModel;
+use yiiunit\framework\db\DatabaseTestCase;
+
+class ExistValidatorTest extends DatabaseTestCase
+{
+	protected $initializeAppWithDb = true;
+	protected $driverName = 'mysql';
+
+	public function setUp()
+	{
+		parent::setUp();
+		ActiveRecord::$db = Yii::$app->getComponent('db');
+	}
+
+	public function tearDown()
+	{
+		parent::tearDown();
+	}
+
+	public function testValidateValueExpectedException()
+	{
+		try {
+			$val = new ExistValidator();
+			$result = $val->validateValue('ref');
+			$this->fail('Exception should have been thrown at this time');
+		} catch (Exception $e) {
+			$this->assertInstanceOf('yii\base\InvalidConfigException', $e);
+			$this->assertEquals('The "className" property must be set.', $e->getMessage());
+		}
+		// combine to save the time creating a new db-fixture set (likely ~5 sec)
+		try {
+			$val = new ExistValidator(array('className' => ExistValidatorMainModel::className()));
+			$val->validateValue('ref');
+			$this->fail('Exception should have been thrown at this time');
+		} catch (Exception $e) {
+			$this->assertInstanceOf('yii\base\InvalidConfigException', $e);
+			$this->assertEquals('The "attributeName" property must be set.', $e->getMessage());
+		}
+	}
+
+	public function testValidateValue()
+	{
+		$val = new ExistValidator(array('className' => ExistValidatorRefModel::className(), 'attributeName' => 'id'));
+		$this->assertTrue($val->validateValue(2));
+		$this->assertTrue($val->validateValue(5));
+		$this->assertFalse($val->validateValue(99));
+		$this->assertFalse($val->validateValue(array('1')));
+	}
+
+	public function testValidateAttribute()
+	{
+		// existing value on different table
+		$val = new ExistValidator(array('className' => ExistValidatorMainModel::className(), 'attributeName' => 'id'));
+		$m = ExistValidatorRefModel::find(array('id' => 1));
+		$val->validateAttribute($m, 'ref');
+		$this->assertFalse($m->hasErrors());
+		// non-existing value on different table
+		$val = new ExistValidator(array('className' => ExistValidatorMainModel::className(), 'attributeName' => 'id'));
+		$m = ExistValidatorRefModel::find(array('id' => 6));
+		$val->validateAttribute($m, 'ref');
+		$this->assertTrue($m->hasErrors('ref'));
+		// existing value on same table
+		$val = new ExistValidator(array('attributeName' => 'ref'));
+		$m = ExistValidatorRefModel::find(array('id' => 2));
+		$val->validateAttribute($m, 'test_val');
+		$this->assertFalse($m->hasErrors());
+		// non-existing value on same table
+		$val = new ExistValidator(array('attributeName' => 'ref'));
+		$m = ExistValidatorRefModel::find(array('id' => 5));
+		$val->validateAttribute($m, 'test_val_fail');
+		$this->assertTrue($m->hasErrors('test_val_fail'));
+		// check for given value (true)
+		$val = new ExistValidator();
+		$m = ExistValidatorRefModel::find(array('id' => 3));
+		$val->validateAttribute($m, 'ref');
+		$this->assertFalse($m->hasErrors());
+		// check for given defaults (false)
+		$val = new ExistValidator();
+		$m = ExistValidatorRefModel::find(array('id' => 4));
+		$m->a_field = 'some new value';
+		$val->validateAttribute($m, 'a_field');
+		$this->assertTrue($m->hasErrors('a_field'));
+	}
+}
\ No newline at end of file