diff --git a/framework/CHANGELOG.md b/framework/CHANGELOG.md
index 456fefa1ff..9442b55f87 100644
--- a/framework/CHANGELOG.md
+++ b/framework/CHANGELOG.md
@@ -4,9 +4,9 @@ Yii Framework 2 Change Log
 2.0.23 under development
 ------------------------
 
-- Bug #17413, #17418: Fixed MSSQL tests (alexkart)
-- Bug #17413: Fixed MSSQL tests: `QueryBuilderTest::testGetColumnType()`, `QueryBuilderTest::testResetSequence()` (alexkart)
+- Bug #17413, #17418, #17426, #17431: Fixed MSSQL tests (alexkart)
 - Bug #17420: Fixed loading of column default values for MSSQL (alexkart)
+- Bug #17395: Fixed issues with actions that contain underscores in their names (alexkart)
 
 
 2.0.22 July 02, 2019
@@ -20,7 +20,6 @@ Yii Framework 2 Change Log
 - Bug #17389: Fixed `UniqueValidator` to work with Active Record having `joinWith()` in its `find()` (garthpmurray)
 - Enh #17382: Added `\yii\validators\DateValidator::$strictDateFormat` to enable strict validation (alexkart)
 - Enh #17396: Added 'invoked by controller' to the debug log message when `\yii\base\Action` is used (alexkart)
-- Bug #17395: Fixed issues with actions that contain underscores in their names (alexkart)
 
 
 2.0.21 June 18, 2019
diff --git a/tests/data/mssql.sql b/tests/data/mssql.sql
index ce8f7343e5..7c95a8ad48 100644
--- a/tests/data/mssql.sql
+++ b/tests/data/mssql.sql
@@ -331,3 +331,34 @@ CREATE TABLE [T_upsert]
 CREATE TABLE [dbo].[table.with.special.characters] (
     [id] [int]
 );
+
+IF OBJECT_ID('[validator_main]', 'U') IS NOT NULL DROP TABLE [dbo].[validator_main];
+IF OBJECT_ID('[validator_ref]', 'U') IS NOT NULL DROP TABLE [dbo].[validator_ref];
+
+create table [dbo].[validator_main]
+(
+    id     int identity
+        constraint validator_main_pk
+            primary key nonclustered,
+    field1 nvarchar(255)
+);
+
+create table [dbo].[validator_ref]
+(
+    id      int identity
+        constraint validator_ref_pk
+            primary key nonclustered,
+    a_field nvarchar(255),
+    ref     int
+);
+
+INSERT INTO [validator_main] (field1) VALUES ('just a string1');
+INSERT INTO [validator_main] (field1) VALUES ('just a string2');
+INSERT INTO [validator_main] (field1) VALUES ('just a string3');
+INSERT INTO [validator_main] (field1) VALUES ('just a string4');
+INSERT INTO [validator_ref] (a_field, ref) VALUES ('ref_to_2', 2);
+INSERT INTO [validator_ref] (a_field, ref) VALUES ('ref_to_2', 2);
+INSERT INTO [validator_ref] (a_field, ref) VALUES ('ref_to_3', 3);
+INSERT INTO [validator_ref] (a_field, ref) VALUES ('ref_to_4', 4);
+INSERT INTO [validator_ref] (a_field, ref) VALUES ('ref_to_4', 4);
+INSERT INTO [validator_ref] (a_field, ref) VALUES ('ref_to_5', 5);
diff --git a/tests/data/postgres.sql b/tests/data/postgres.sql
index c2bd8c519e..bc61454811 100644
--- a/tests/data/postgres.sql
+++ b/tests/data/postgres.sql
@@ -309,11 +309,11 @@ DROP TABLE IF EXISTS "validatorMain" CASCADE;
 DROP TABLE IF EXISTS "validatorRef" CASCADE;
 
 CREATE TABLE "validator_main" (
-  id integer not null primary key,
+  id serial primary key,
   field1 VARCHAR(255)
 );
 CREATE TABLE "validator_ref" (
-  id integer not null primary key,
+  id serial primary key,
   a_field VARCHAR(255),
   ref     integer
 );
@@ -328,16 +328,16 @@ CREATE TABLE "validatorRef" (
   CONSTRAINT "validatorRef_id" FOREIGN KEY ("ref") REFERENCES "validatorMain" ("id") ON DELETE CASCADE ON UPDATE CASCADE
 );
 
-INSERT INTO "validator_main" (id, field1) VALUES (1, 'just a string1');
-INSERT INTO "validator_main" (id, field1) VALUES (2, 'just a string2');
-INSERT INTO "validator_main" (id, field1) VALUES (3, 'just a string3');
-INSERT INTO "validator_main" (id, field1) VALUES (4, 'just a string4');
-INSERT INTO "validator_ref" (id, a_field, ref) VALUES (1, 'ref_to_2', 2);
-INSERT INTO "validator_ref" (id, a_field, ref) VALUES (2, 'ref_to_2', 2);
-INSERT INTO "validator_ref" (id, a_field, ref) VALUES (3, 'ref_to_3', 3);
-INSERT INTO "validator_ref" (id, a_field, ref) VALUES (4, 'ref_to_4', 4);
-INSERT INTO "validator_ref" (id, a_field, ref) VALUES (5, 'ref_to_4', 4);
-INSERT INTO "validator_ref" (id, a_field, ref) VALUES (6, 'ref_to_5', 5);
+INSERT INTO "validator_main" (field1) VALUES ('just a string1');
+INSERT INTO "validator_main" (field1) VALUES ('just a string2');
+INSERT INTO "validator_main" (field1) VALUES ('just a string3');
+INSERT INTO "validator_main" (field1) VALUES ('just a string4');
+INSERT INTO "validator_ref" (a_field, ref) VALUES ('ref_to_2', 2);
+INSERT INTO "validator_ref" (a_field, ref) VALUES ('ref_to_2', 2);
+INSERT INTO "validator_ref" (a_field, ref) VALUES ('ref_to_3', 3);
+INSERT INTO "validator_ref" (a_field, ref) VALUES ('ref_to_4', 4);
+INSERT INTO "validator_ref" (a_field, ref) VALUES ('ref_to_4', 4);
+INSERT INTO "validator_ref" (a_field, ref) VALUES ('ref_to_5', 5);
 INSERT INTO "validatorMain" (id, field1) VALUES (2, 'just a string2');
 INSERT INTO "validatorMain" (id, field1) VALUES (3, 'just a string3');
 INSERT INTO "validatorRef" (id, a_field, ref) VALUES (1, 'ref_to_2', 2);
diff --git a/tests/framework/db/mssql/QueryBuilderTest.php b/tests/framework/db/mssql/QueryBuilderTest.php
index 802a281b6b..397f5a9321 100644
--- a/tests/framework/db/mssql/QueryBuilderTest.php
+++ b/tests/framework/db/mssql/QueryBuilderTest.php
@@ -70,6 +70,7 @@ class QueryBuilderTest extends \yiiunit\framework\db\QueryBuilderTest
 
     public function testCommentColumn()
     {
+        // related to https://github.com/yiisoft/yii2/pull/17364
         $this->markTestSkipped('Should be fixed');
 
         $qb = $this->getQueryBuilder();
@@ -85,9 +86,8 @@ class QueryBuilderTest extends \yiiunit\framework\db\QueryBuilderTest
 
     public function testCommentTable()
     {
-        if ($this->driverName === 'sqlsrv') {
-            $this->markTestSkipped('Should be fixed');
-        }
+        // related to https://github.com/yiisoft/yii2/pull/17364
+        $this->markTestSkipped('Should be fixed');
 
         $qb = $this->getQueryBuilder();
 
diff --git a/tests/framework/validators/ExistValidatorTest.php b/tests/framework/validators/ExistValidatorTest.php
index 1e1b140b6d..d55097ed4b 100644
--- a/tests/framework/validators/ExistValidatorTest.php
+++ b/tests/framework/validators/ExistValidatorTest.php
@@ -50,10 +50,6 @@ abstract class ExistValidatorTest extends DatabaseTestCase
 
     public function testValidateValue()
     {
-        if ($this->driverName === 'sqlsrv') {
-            $this->markTestSkipped('Should be fixed');
-        }
-
         $val = new ExistValidator(['targetClass' => ValidatorTestRefModel::className(), 'targetAttribute' => 'id']);
         $this->assertTrue($val->validate(2));
         $this->assertTrue($val->validate(5));
@@ -63,10 +59,6 @@ abstract class ExistValidatorTest extends DatabaseTestCase
 
     public function testValidateAttribute()
     {
-        if ($this->driverName === 'sqlsrv') {
-            $this->markTestSkipped('Should be fixed');
-        }
-
         // existing value on different table
         $val = new ExistValidator(['targetClass' => ValidatorTestMainModel::className(), 'targetAttribute' => 'id']);
         $m = ValidatorTestRefModel::findOne(['id' => 1]);
@@ -216,10 +208,6 @@ abstract class ExistValidatorTest extends DatabaseTestCase
 
     public function testTargetRelation()
     {
-        if ($this->driverName === 'sqlsrv') {
-            $this->markTestSkipped('Should be fixed');
-        }
-
         $val = new ExistValidator(['targetRelation' => 'references']);
 
         $m = ValidatorTestMainModel::findOne(2);
@@ -233,10 +221,6 @@ abstract class ExistValidatorTest extends DatabaseTestCase
 
     public function testTargetRelationWithFilter()
     {
-        if ($this->driverName === 'sqlsrv') {
-            $this->markTestSkipped('Should be fixed');
-        }
-
         $val = new ExistValidator(['targetRelation' => 'references', 'filter' => function ($query) {
             $query->andWhere(['a_field' => 'ref_to_2']);
         }]);
@@ -254,10 +238,6 @@ abstract class ExistValidatorTest extends DatabaseTestCase
     
     public function testForceMaster()
     {
-        if ($this->driverName === 'sqlsrv') {
-            $this->markTestSkipped('Should be fixed');
-        }
-
         $connection = $this->getConnectionWithInvalidSlave();
         ActiveRecord::$db = $connection;
 
diff --git a/tests/framework/validators/UniqueValidatorTest.php b/tests/framework/validators/UniqueValidatorTest.php
index 148cdbf893..ea673e2906 100644
--- a/tests/framework/validators/UniqueValidatorTest.php
+++ b/tests/framework/validators/UniqueValidatorTest.php
@@ -95,10 +95,6 @@ abstract class UniqueValidatorTest extends DatabaseTestCase
 
     public function testValidateAttributeDefault()
     {
-        if ($this->driverName === 'sqlsrv') {
-            $this->markTestSkipped('Should be fixed');
-        }
-
         $val = new UniqueValidator();
         $m = ValidatorTestMainModel::find()->one();
         $val->validateAttribute($m, 'id');
@@ -113,7 +109,6 @@ abstract class UniqueValidatorTest extends DatabaseTestCase
         $val->validateAttribute($m, 'ref');
         $this->assertTrue($m->hasErrors('ref'));
         $m = new ValidatorTestRefModel();
-        $m->id = 7;
         $m->ref = 12121;
         $val->validateAttribute($m, 'ref');
         $this->assertFalse($m->hasErrors('ref'));
@@ -128,10 +123,6 @@ abstract class UniqueValidatorTest extends DatabaseTestCase
 
     public function testValidateAttributeOfNonARModel()
     {
-        if ($this->driverName === 'sqlsrv') {
-            $this->markTestSkipped('Should be fixed');
-        }
-
         $val = new UniqueValidator(['targetClass' => ValidatorTestRefModel::className(), 'targetAttribute' => 'ref']);
         $m = FakedValidationModel::createWithAttributes(['attr_1' => 5, 'attr_2' => 1313]);
         $val->validateAttribute($m, 'attr_1');
@@ -142,10 +133,6 @@ abstract class UniqueValidatorTest extends DatabaseTestCase
 
     public function testValidateNonDatabaseAttribute()
     {
-        if ($this->driverName === 'sqlsrv') {
-            $this->markTestSkipped('Should be fixed');
-        }
-
         $val = new UniqueValidator(['targetClass' => ValidatorTestRefModel::className(), 'targetAttribute' => 'ref']);
         /** @var ValidatorTestMainModel $m */
         $m = ValidatorTestMainModel::findOne(1);
@@ -221,14 +208,10 @@ abstract class UniqueValidatorTest extends DatabaseTestCase
 
     public function testValidateTargetClass()
     {
-        if ($this->driverName === 'sqlsrv') {
-            $this->markTestSkipped('Should be fixed');
-        }
-
-        // Check whether "Description" and "address" aren't equal
+        // Check whether "Description" and "name" aren't equal
         $val = new UniqueValidator([
             'targetClass' => Customer::className(),
-            'targetAttribute' => ['description' => 'address'],
+            'targetAttribute' => ['description' => 'name'],
         ]);
 
         /** @var Profile $m */
@@ -238,16 +221,16 @@ abstract class UniqueValidatorTest extends DatabaseTestCase
         $this->assertFalse($m->hasErrors('description'));
 
         // ID of Profile is not equal to ID of Customer
-        // (1, description = address2) <=> (2, address = address2)
-        $m->description = 'address2';
+        // (1, description = user2) <=> (2, name = user2)
+        $m->description = 'user2';
         $val->validateAttribute($m, 'description');
         $this->assertTrue($m->hasErrors('description'));
         $m->clearErrors('description');
 
         // ID of Profile IS equal to ID of Customer
-        // (1, description = address1) <=> (1, address = address1)
+        // (1, description = user1) <=> (1, name = user1)
         // https://github.com/yiisoft/yii2/issues/10263
-        $m->description = 'address1';
+        $m->description = 'user1';
         $val->validateAttribute($m, 'description');
         $this->assertTrue($m->hasErrors('description'));
     }
@@ -294,44 +277,32 @@ abstract class UniqueValidatorTest extends DatabaseTestCase
 
     public function testValidateEmptyAttributeInStringField()
     {
-        if ($this->driverName === 'sqlsrv') {
-            $this->markTestSkipped('Should be fixed');
-        }
-
         ValidatorTestMainModel::deleteAll();
 
         $val = new UniqueValidator();
 
         $m = new ValidatorTestMainModel(['field1' => '']);
-        $m->id = 1;
         $val->validateAttribute($m, 'field1');
         $this->assertFalse($m->hasErrors('field1'));
         $m->save(false);
 
         $m = new ValidatorTestMainModel(['field1' => '']);
-        $m->id = 2;
         $val->validateAttribute($m, 'field1');
         $this->assertTrue($m->hasErrors('field1'));
     }
 
     public function testValidateEmptyAttributeInIntField()
     {
-        if ($this->driverName === 'sqlsrv') {
-            $this->markTestSkipped('Should be fixed');
-        }
-
         ValidatorTestRefModel::deleteAll();
 
         $val = new UniqueValidator();
 
         $m = new ValidatorTestRefModel(['ref' => 0]);
-        $m->id = 1;
         $val->validateAttribute($m, 'ref');
         $this->assertFalse($m->hasErrors('ref'));
         $m->save(false);
 
         $m = new ValidatorTestRefModel(['ref' => 0]);
-        $m->id = 2;
         $val->validateAttribute($m, 'ref');
         $this->assertTrue($m->hasErrors('ref'));
     }
@@ -424,17 +395,12 @@ abstract class UniqueValidatorTest extends DatabaseTestCase
      */
     public function testAmbiguousColumnName()
     {
-        if ($this->driverName === 'sqlsrv') {
-            $this->markTestSkipped('Should be fixed');
-        }
-
         $validator = new UniqueValidator([
             'filter' => function ($query) {
                 $query->joinWith('items', false);
             },
         ]);
         $model = new Order();
-        $model->id = 42;
         $model->customer_id = 1;
         $model->total = 800;
         $model->save(false);
@@ -448,17 +414,12 @@ abstract class UniqueValidatorTest extends DatabaseTestCase
      */
     public function testExpressionInAttributeColumnName()
     {
-        if ($this->driverName === 'sqlsrv') {
-            $this->markTestSkipped('Should be fixed');
-        }
-
         $validator = new UniqueValidator([
             'targetAttribute' => [
                 'title' => 'LOWER(title)',
             ],
         ]);
         $model = new Document();
-        $model->id = 42;
         $model->title = 'Test';
         $model->content = 'test';
         $model->version = 1;