diff --git a/core/tests/Drupal/FunctionalTests/Installer/InstallerDatabaseErrorMessagesTest.php b/core/tests/Drupal/FunctionalTests/Installer/InstallerDatabaseErrorMessagesTest.php
index 036196471e11..021fbc9a221c 100644
--- a/core/tests/Drupal/FunctionalTests/Installer/InstallerDatabaseErrorMessagesTest.php
+++ b/core/tests/Drupal/FunctionalTests/Installer/InstallerDatabaseErrorMessagesTest.php
@@ -24,17 +24,7 @@ class InstallerDatabaseErrorMessagesTest extends InstallerTestBase {
     // it will try and create the drupal_install_test table as this is part of
     // the standard database tests performed by the installer in
     // Drupal\Core\Database\Install\Tasks.
-    $spec = [
-      'fields' => [
-        'id' => [
-          'type' => 'int',
-          'not null' => TRUE,
-        ],
-      ],
-      'primary key' => ['id'],
-    ];
-
-    Database::getConnection('default')->schema()->createTable('drupal_install_test', $spec);
+    Database::getConnection('default')->query('CREATE TABLE {drupal_install_test} (id int NOT NULL PRIMARY KEY)');
     parent::setUpSettings();
   }
 
diff --git a/core/tests/Drupal/FunctionalTests/Installer/InstallerTranslationTest.php b/core/tests/Drupal/FunctionalTests/Installer/InstallerTranslationTest.php
index 4ce80621bf07..5d86fc54fdb3 100644
--- a/core/tests/Drupal/FunctionalTests/Installer/InstallerTranslationTest.php
+++ b/core/tests/Drupal/FunctionalTests/Installer/InstallerTranslationTest.php
@@ -53,17 +53,7 @@ class InstallerTranslationTest extends InstallerTestBase {
     // it will try and create the drupal_install_test table as this is part of
     // the standard database tests performed by the installer in
     // Drupal\Core\Database\Install\Tasks.
-    $spec = [
-      'fields' => [
-        'id' => [
-          'type' => 'int',
-          'not null' => TRUE,
-        ],
-      ],
-      'primary key' => ['id'],
-    ];
-
-    Database::getConnection('default')->schema()->createTable('drupal_install_test', $spec);
+    Database::getConnection('default')->query('CREATE TABLE {drupal_install_test} (id int NOT NULL PRIMARY KEY)');
     parent::setUpSettings();
 
     // Ensure that the error message translation is working.
@@ -73,7 +63,7 @@ class InstallerTranslationTest extends InstallerTestBase {
     // cSpell:enable
 
     // Now do it successfully.
-    Database::getConnection('default')->schema()->dropTable('drupal_install_test');
+    Database::getConnection('default')->query('DROP TABLE {drupal_install_test}');
     parent::setUpSettings();
   }
 
diff --git a/core/tests/Drupal/FunctionalTests/Update/UpdatePathTestBaseTest.php b/core/tests/Drupal/FunctionalTests/Update/UpdatePathTestBaseTest.php
index 689abd66767a..34d2e8682974 100644
--- a/core/tests/Drupal/FunctionalTests/Update/UpdatePathTestBaseTest.php
+++ b/core/tests/Drupal/FunctionalTests/Update/UpdatePathTestBaseTest.php
@@ -41,10 +41,7 @@ class UpdatePathTestBaseTest extends UpdatePathTestBase {
     // Ensure that all {router} entries can be unserialized. If they cannot be
     // unserialized a notice will be thrown by PHP.
 
-    $result = \Drupal::database()->select('router', 'r')
-      ->fields('r', ['name', 'route'])
-      ->execute()
-      ->fetchAllKeyed(0, 1);
+    $result = \Drupal::database()->query("SELECT name, route from {router}")->fetchAllKeyed(0, 1);
     // For the purpose of fetching the notices and displaying more helpful error
     // messages, let's override the error handler temporarily.
     set_error_handler(function ($severity, $message, $filename, $lineno) {
diff --git a/core/tests/Drupal/KernelTests/Core/Command/DbDumpTest.php b/core/tests/Drupal/KernelTests/Core/Command/DbDumpTest.php
index 3e16fff33316..2192d0ec73ca 100644
--- a/core/tests/Drupal/KernelTests/Core/Command/DbDumpTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Command/DbDumpTest.php
@@ -213,7 +213,7 @@ class DbDumpTest extends KernelTestBase {
     }
 
     // Ensure the test config has been replaced.
-    $config = unserialize($connection->select('config', 'c')->fields('c', ['data'])->condition('name', 'test_config')->execute()->fetchField());
+    $config = unserialize($connection->query("SELECT data FROM {config} WHERE name = 'test_config'")->fetchField());
     $this->assertIdentical($config, $this->data, 'Script has properly restored the config table data.');
 
     // Ensure the cache data was not exported.
diff --git a/core/tests/Drupal/KernelTests/Core/Config/Storage/DatabaseStorageTest.php b/core/tests/Drupal/KernelTests/Core/Config/Storage/DatabaseStorageTest.php
index b26b3fd53c6b..3bc7738d20bc 100644
--- a/core/tests/Drupal/KernelTests/Core/Config/Storage/DatabaseStorageTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/Storage/DatabaseStorageTest.php
@@ -26,7 +26,7 @@ class DatabaseStorageTest extends ConfigStorageTestBase {
   }
 
   protected function read($name) {
-    $data = Database::getConnection()->select('config', 'c')->fields('c', ['data'])->condition('name', $name)->execute()->fetchField();
+    $data = Database::getConnection()->query('SELECT data FROM {config} WHERE name = :name', [':name' => $name])->fetchField();
     return unserialize($data);
   }
 
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/EntityApiTest.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityApiTest.php
index f9ec4d59a1f7..6b8e5149432c 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/EntityApiTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityApiTest.php
@@ -97,16 +97,15 @@ class EntityApiTest extends EntityKernelTestBase {
     // Verify that all data got deleted.
     $definition = \Drupal::entityTypeManager()->getDefinition($entity_type);
     $connection = Database::getConnection();
-    $this->assertEqual(0, (int) $connection->select($definition->getBaseTable())->countQuery()->execute()->fetchField(), 'Base table was emptied');
-
+    $this->assertEqual(0, $connection->query('SELECT COUNT(*) FROM {' . $definition->getBaseTable() . '}')->fetchField(), 'Base table was emptied');
     if ($data_table = $definition->getDataTable()) {
-      $this->assertEqual(0, (int) $connection->select($data_table)->countQuery()->execute()->fetchField(), 'Data table was emptied');
+      $this->assertEqual(0, $connection->query('SELECT COUNT(*) FROM {' . $data_table . '}')->fetchField(), 'Data table was emptied');
     }
     if ($revision_table = $definition->getRevisionTable()) {
-      $this->assertEqual(0, (int) $connection->select($revision_table)->countQuery()->execute()->fetchField(), 'Revision table was emptied');
+      $this->assertEqual(0, $connection->query('SELECT COUNT(*) FROM {' . $revision_table . '}')->fetchField(), 'Data table was emptied');
     }
     if ($revision_data_table = $definition->getRevisionDataTable()) {
-      $this->assertEqual(0, (int) $connection->select($revision_data_table)->countQuery()->execute()->fetchField(), 'Revision data table was emptied');
+      $this->assertEqual(0, $connection->query('SELECT COUNT(*) FROM {' . $revision_data_table . '}')->fetchField(), 'Data table was emptied');
     }
 
     // Test deleting a list of entities not indexed by entity id.
@@ -126,16 +125,15 @@ class EntityApiTest extends EntityKernelTestBase {
 
     // Verify that all data got deleted from the tables.
     $definition = \Drupal::entityTypeManager()->getDefinition($entity_type);
-    $this->assertEqual(0, (int) $connection->select($definition->getBaseTable())->countQuery()->execute()->fetchField(), 'Base table was emptied');
-
+    $this->assertEqual(0, $connection->query('SELECT COUNT(*) FROM {' . $definition->getBaseTable() . '}')->fetchField(), 'Base table was emptied');
     if ($data_table = $definition->getDataTable()) {
-      $this->assertEqual(0, (int) $connection->select($data_table)->countQuery()->execute()->fetchField(), 'Data table was emptied');
+      $this->assertEqual(0, $connection->query('SELECT COUNT(*) FROM {' . $data_table . '}')->fetchField(), 'Data table was emptied');
     }
     if ($revision_table = $definition->getRevisionTable()) {
-      $this->assertEqual(0, (int) $connection->select($revision_table)->countQuery()->execute()->fetchField(), 'Revision table was emptied');
+      $this->assertEqual(0, $connection->query('SELECT COUNT(*) FROM {' . $revision_table . '}')->fetchField(), 'Data table was emptied');
     }
     if ($revision_data_table = $definition->getRevisionDataTable()) {
-      $this->assertEqual(0, (int) $connection->select($revision_data_table)->countQuery()->execute()->fetchField(), 'Revision data table was emptied');
+      $this->assertEqual(0, $connection->query('SELECT COUNT(*) FROM {' . $revision_data_table . '}')->fetchField(), 'Data table was emptied');
     }
   }
 
diff --git a/core/tests/Drupal/KernelTests/Core/Entity/RevisionableContentEntityBaseTest.php b/core/tests/Drupal/KernelTests/Core/Entity/RevisionableContentEntityBaseTest.php
index 6cb8c139969f..c83a6bde4caf 100644
--- a/core/tests/Drupal/KernelTests/Core/Entity/RevisionableContentEntityBaseTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/RevisionableContentEntityBaseTest.php
@@ -169,11 +169,10 @@ class RevisionableContentEntityBaseTest extends EntityKernelTestBase {
    */
   protected function assertItemsTableCount($count, EntityTypeInterface $definition) {
     $connection = Database::getConnection();
-    $this->assertEqual(1, (int) $connection->select($definition->getBaseTable())->countQuery()->execute()->fetchField());
-    $this->assertEqual(1, (int) $connection->select($definition->getDataTable())->countQuery()->execute()->fetchField());
-    $this->assertEqual($count, (int) $connection->select($definition->getRevisionTable())->countQuery()->execute()->fetchField());
-    $this->assertEqual($count, (int) $connection->select($definition->getRevisionDataTable())->countQuery()->execute()->fetchField());
-
+    $this->assertEqual(1, $connection->query('SELECT COUNT(*) FROM {' . $definition->getBaseTable() . '}')->fetchField());
+    $this->assertEqual(1, $connection->query('SELECT COUNT(*) FROM {' . $definition->getDataTable() . '}')->fetchField());
+    $this->assertEqual($count, $connection->query('SELECT COUNT(*) FROM {' . $definition->getRevisionTable() . '}')->fetchField());
+    $this->assertEqual($count, $connection->query('SELECT COUNT(*) FROM {' . $definition->getRevisionDataTable() . '}')->fetchField());
   }
 
   /**
diff --git a/core/tests/Drupal/KernelTests/Core/KeyValueStore/GarbageCollectionTest.php b/core/tests/Drupal/KernelTests/Core/KeyValueStore/GarbageCollectionTest.php
index 6d774687f970..c702fb92967e 100644
--- a/core/tests/Drupal/KernelTests/Core/KeyValueStore/GarbageCollectionTest.php
+++ b/core/tests/Drupal/KernelTests/Core/KeyValueStore/GarbageCollectionTest.php
@@ -60,11 +60,11 @@ class GarbageCollectionTest extends KernelTestBase {
     system_cron();
 
     // Query the database and confirm that the stale records were deleted.
-    $result = $connection->select('key_value_expire', 'kvp')
-      ->fields('kvp', ['name'])
-      ->condition('collection', $collection)
-      ->execute()
-      ->fetchAll();
+    $result = $connection->query(
+      'SELECT name, value FROM {key_value_expire} WHERE collection = :collection',
+      [
+        ':collection' => $collection,
+      ])->fetchAll();
     $this->assertCount(1, $result, 'Only one item remains after garbage collection');
 
   }
diff --git a/core/tests/Drupal/KernelTests/Core/Routing/MatcherDumperTest.php b/core/tests/Drupal/KernelTests/Core/Routing/MatcherDumperTest.php
index e0d3e8a59d2c..41873110a43a 100644
--- a/core/tests/Drupal/KernelTests/Core/Routing/MatcherDumperTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Routing/MatcherDumperTest.php
@@ -118,11 +118,7 @@ class MatcherDumperTest extends KernelTestBase {
 
     $dumper->dump(['provider' => 'test']);
 
-    $record = $connection->select('test_routes', 'tr')
-      ->fields('tr')
-      ->condition('name', 'test_route')
-      ->execute()
-      ->fetchObject();
+    $record = $connection->query("SELECT * FROM {test_routes} WHERE name= :name", [':name' => 'test_route'])->fetchObject();
 
     $loaded_route = unserialize($record->route);
 
diff --git a/core/tests/Drupal/KernelTests/KernelTestBaseTest.php b/core/tests/Drupal/KernelTests/KernelTestBaseTest.php
index b082db213a95..26e0d8ed4e9b 100644
--- a/core/tests/Drupal/KernelTests/KernelTestBaseTest.php
+++ b/core/tests/Drupal/KernelTests/KernelTestBaseTest.php
@@ -297,11 +297,11 @@ class KernelTestBaseTest extends KernelTestBase {
       $this->assertTrue(empty($tables), 'All test tables have been removed.');
     }
     else {
-      $result = $connection->select($this->databasePrefix . "sqlite_master", 'sql_m')->fields('sql_m', ['name'])
-        ->condition('type', 'table')
-        ->condition('name', '%', 'LIKE')
-        ->condition('name', 'sqlite_%', 'NOT LIKE')
-        ->execute()->fetchAllKeyed(0, 0);
+      $result = $connection->query("SELECT name FROM " . $this->databasePrefix . ".sqlite_master WHERE type = :type AND name LIKE :table_name AND name NOT LIKE :pattern", [
+        ':type' => 'table',
+        ':table_name' => '%',
+        ':pattern' => 'sqlite_%',
+      ])->fetchAllKeyed(0, 0);
 
       $this->assertTrue(empty($result), 'All test tables have been removed.');
     }