diff -u b/core/includes/database.inc b/core/includes/database.inc
--- b/core/includes/database.inc
+++ b/core/includes/database.inc
@@ -155,7 +155,7 @@
  * @see \Drupal\Core\Database\Connection::defaultOptions()
  */
 function db_insert($table, array $options = []) {
-  @trigger_error('db_insert() is deprecated in Drupal 8.0.x and will be removed before Drupal 9.0.0. Use \Drupal\Core\Database\Database::getConnection()->insert() instead. See https://www.drupal.org/node/2989742', E_USER_DEPRECATED);
+  @trigger_error('db_insert() is deprecated in Drupal 8.0.x and will be removed before Drupal 9.0.0. Instead, get a database connection injected into your service from the container and call call insert() on it. For example, $injected_database->insert($table, $options); See https://www.drupal.org/node/2993033', E_USER_DEPRECATED);
   if (empty($options['target']) || $options['target'] == 'replica') {
     $options['target'] = 'default';
   }
diff -u b/core/modules/contact/tests/drupal-7.contact.database.php b/core/modules/contact/tests/drupal-7.contact.database.php
--- b/core/modules/contact/tests/drupal-7.contact.database.php
+++ b/core/modules/contact/tests/drupal-7.contact.database.php
@@ -17,7 +17,7 @@
   ->execute();
 
 // Add a custom contact category.
-\Drupal::database()->insert('contact')->fields([
+$connection->insert('contact')->fields([
   'category',
   'recipients',
   'reply',
diff -u b/core/modules/file/tests/src/Kernel/UsageTest.php b/core/modules/file/tests/src/Kernel/UsageTest.php
--- b/core/modules/file/tests/src/Kernel/UsageTest.php
+++ b/core/modules/file/tests/src/Kernel/UsageTest.php
@@ -22,7 +22,8 @@
    */
   public function testGetUsage() {
     $file = $this->createFile();
-    \Drupal::database()->insert('file_usage')
+    $connection = \Drupal::database();
+    $connection->insert('file_usage')
       ->fields([
         'fid' => $file->id(),
         'module' => 'testing',
@@ -31,7 +32,7 @@
         'count' => 1,
       ])
       ->execute();
-    \Drupal::database()->insert('file_usage')
+    $connection->insert('file_usage')
       ->fields([
         'fid' => $file->id(),
         'module' => 'testing',
@@ -105,7 +106,8 @@
     $file = $this->createFile();
     $file->setPermanent();
     $file_usage = $this->container->get('file.usage');
-    \Drupal::database()->insert('file_usage')
+    $connection = Database::getConnection();
+    $connection->insert('file_usage')
       ->fields([
         'fid' => $file->id(),
         'module' => 'testing',
diff -u b/core/modules/history/tests/src/Kernel/Views/HistoryTimestampTest.php b/core/modules/history/tests/src/Kernel/Views/HistoryTimestampTest.php
--- b/core/modules/history/tests/src/Kernel/Views/HistoryTimestampTest.php
+++ b/core/modules/history/tests/src/Kernel/Views/HistoryTimestampTest.php
@@ -67,14 +67,15 @@
     $account->save();
     \Drupal::currentUser()->setAccount($account);
 
-    \Drupal::database()->insert('history')
+    $connection = \Drupal::database();
+    $connection->insert('history')
       ->fields([
         'uid' => $account->id(),
         'nid' => $nodes[0]->id(),
         'timestamp' => REQUEST_TIME - 100,
       ])->execute();
 
-    \Drupal::database()->insert('history')
+    $connection->insert('history')
       ->fields([
         'uid' => $account->id(),
         'nid' => $nodes[1]->id(),
diff -u b/core/modules/locale/tests/src/Functional/LocaleUpdateBase.php b/core/modules/locale/tests/src/Functional/LocaleUpdateBase.php
--- b/core/modules/locale/tests/src/Functional/LocaleUpdateBase.php
+++ b/core/modules/locale/tests/src/Functional/LocaleUpdateBase.php
@@ -2,6 +2,7 @@
 
 namespace Drupal\Tests\locale\Functional;
 
+use Drupal\Core\Database\Database;
 use Drupal\Core\StreamWrapper\PublicStream;
 use Drupal\file\Entity\File;
 use Drupal\Tests\BrowserTestBase;
@@ -278,9 +279,10 @@
       'filename' => 'custom_module_one.de.po',
       'version' => '',
     ];
+    $connection = Database::getConnection();
     foreach ($data as $file) {
       $file = array_merge($default, $file);
-      \Drupal::database()->insert('locale_file')->fields($file)->execute();
+      $connection->insert('locale_file')->fields($file)->execute();
     }
   }
 
diff -u b/core/modules/node/node.install b/core/modules/node/node.install
--- b/core/modules/node/node.install
+++ b/core/modules/node/node.install
@@ -134,7 +134,7 @@
   }
 
   // Populate the node access table.
-  \Drupal::database()->insert('node_access')
+  Database::getConnection()->insert('node_access')
     ->fields([
       'nid' => 0,
       'gid' => 0,
diff -u b/core/modules/node/tests/src/Functional/NodeAccessGrantsCacheContextTest.php b/core/modules/node/tests/src/Functional/NodeAccessGrantsCacheContextTest.php
--- b/core/modules/node/tests/src/Functional/NodeAccessGrantsCacheContextTest.php
+++ b/core/modules/node/tests/src/Functional/NodeAccessGrantsCacheContextTest.php
@@ -2,6 +2,8 @@
 
 namespace Drupal\Tests\node\Functional;
 
+use Drupal\Core\Database\Database;
+
 /**
  * Tests the node access grants cache context service.
  *
@@ -92,7 +94,7 @@
       'grant_update' => 0,
       'grant_delete' => 0,
     ];
-    \Drupal::database()->insert('node_access')->fields($record)->execute();
+    Database::getConnection()->insert('node_access')->fields($record)->execute();
 
     // Put user accessUser (uid 0) in the realm.
     \Drupal::state()->set('node_access_test.no_access_uid', 0);
diff -u b/core/modules/node/tests/src/Functional/NodeQueryAlterTest.php b/core/modules/node/tests/src/Functional/NodeQueryAlterTest.php
--- b/core/modules/node/tests/src/Functional/NodeQueryAlterTest.php
+++ b/core/modules/node/tests/src/Functional/NodeQueryAlterTest.php
@@ -2,6 +2,8 @@
 
 namespace Drupal\Tests\node\Functional;
 
+use Drupal\Core\Database\Database;
+
 /**
  * Tests that node access queries are properly altered by the node module.
  *
@@ -151,7 +153,8 @@
       'grant_update' => 0,
       'grant_delete' => 0,
     ];
-    \Drupal::database()->insert('node_access')->fields($record)->execute();
+    $connection = Database::getConnection();
+    $connection->insert('node_access')->fields($record)->execute();
 
     // Test that the noAccessUser still doesn't have the 'view'
     // privilege after adding the node_access record.
diff -u b/core/modules/search/search.module b/core/modules/search/search.module
--- b/core/modules/search/search.module
+++ b/core/modules/search/search.module
@@ -539,7 +539,7 @@
 
   $connection = \Drupal::database();
   // Insert cleaned up data into dataset
-  \Drupal::database()->insert('search_dataset')
+  $connection->insert('search_dataset')
     ->fields([
       'sid' => $sid,
       'langcode' => $langcode,
diff -u b/core/modules/search/tests/src/Functional/SearchRankingTest.php b/core/modules/search/tests/src/Functional/SearchRankingTest.php
--- b/core/modules/search/tests/src/Functional/SearchRankingTest.php
+++ b/core/modules/search/tests/src/Functional/SearchRankingTest.php
@@ -4,6 +4,7 @@
 
 use Drupal\comment\Plugin\Field\FieldType\CommentItemInterface;
 use Drupal\comment\Tests\CommentTestTrait;
+use Drupal\Core\Database\Database;
 use Drupal\Core\Url;
 use Drupal\filter\Entity\FilterFormat;
 use Drupal\search\Entity\SearchPage;
@@ -104,7 +105,7 @@
     // to the Statistics module. So instead go ahead and manually update the
     // counter for this node.
     $nid = $nodes['views'][1]->id();
-    \Drupal::database()->insert('node_counter')
+    Database::getConnection()->insert('node_counter')
       ->fields(['totalcount' => 5, 'daycount' => 5, 'timestamp' => REQUEST_TIME, 'nid' => $nid])
       ->execute();
 
diff -u b/core/modules/system/tests/modules/module_test/module_test.install b/core/modules/system/tests/modules/module_test/module_test.install
--- b/core/modules/system/tests/modules/module_test/module_test.install
+++ b/core/modules/system/tests/modules/module_test/module_test.install
@@ -5,6 +5,8 @@
  * Install, update and uninstall functions for the module_test module.
  */
 
+use Drupal\Core\Database\Database;
+
 /**
  * Implements hook_schema().
  */
@@ -29,7 +31,7 @@
  */
 function module_test_install() {
   $schema = drupal_get_module_schema('module_test', 'module_test');
-  \Drupal::database()->insert('module_test')
+  Database::getConnection()->insert('module_test')
     ->fields([
       'data' => $schema['fields']['data']['type'],
     ])
diff -u b/core/modules/tracker/tracker.module b/core/modules/tracker/tracker.module
--- b/core/modules/tracker/tracker.module
+++ b/core/modules/tracker/tracker.module
@@ -55,6 +55,7 @@
       ->execute();
 
     $nodes = Node::loadMultiple($nids);
+    $connection = \Drupal::database();
     foreach ($nodes as $nid => $node) {
 
       // Calculate the changed timestamp for this node.
@@ -69,7 +70,7 @@
         ->execute();
 
       // Insert the node-level data.
-      \Drupal::database()->insert('tracker_node')
+      $connection->insert('tracker_node')
         ->fields([
           'nid' => $nid,
           'published' => (int) $node->isPublished(),
@@ -78,7 +79,7 @@
         ->execute();
 
       // Insert the user-level data for the node's author.
-      \Drupal::database()->insert('tracker_user')
+      $connection->insert('tracker_user')
         ->fields([
           'nid' => $nid,
           'published' => (int) $node->isPublished(),
@@ -101,7 +102,7 @@
         ->groupBy('uid')
         ->execute();
       if ($result) {
-        $query = \Drupal::database()->insert('tracker_user');
+        $query = $connection->insert('tracker_user');
         foreach ($result as $row) {
           $query->fields([
             'uid' => $row['uid'],
diff -u b/core/modules/views/tests/src/Functional/ViewTestBase.php b/core/modules/views/tests/src/Functional/ViewTestBase.php
--- b/core/modules/views/tests/src/Functional/ViewTestBase.php
+++ b/core/modules/views/tests/src/Functional/ViewTestBase.php
@@ -3,6 +3,7 @@
 namespace Drupal\Tests\views\Functional;
 
 use Behat\Mink\Exception\ElementNotFoundException;
+use Drupal\Core\Database\Database;
 use Drupal\Core\Database\Query\SelectInterface;
 use Drupal\Tests\BrowserTestBase;
 use Drupal\views\Tests\ViewResultAssertionTrait;
@@ -55,7 +56,7 @@
 
     // Load the test dataset.
     $data_set = $this->dataSet();
-    $query = \Drupal::database()->insert('views_test_data')
+    $query = Database::getConnection()->insert('views_test_data')
       ->fields(array_keys($data_set[0]));
     foreach ($data_set as $record) {
       $query->values($record);
diff -u b/core/tests/Drupal/KernelTests/Core/Config/Storage/DatabaseStorageTest.php b/core/tests/Drupal/KernelTests/Core/Config/Storage/DatabaseStorageTest.php
--- b/core/tests/Drupal/KernelTests/Core/Config/Storage/DatabaseStorageTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Config/Storage/DatabaseStorageTest.php
@@ -31,7 +31,7 @@
   }
 
   protected function insert($name, $data) {
-    \Drupal::database()->insert('config')->fields(['name' => $name, 'data' => $data])->execute();
+    Database::getConnection()->insert('config')->fields(['name' => $name, 'data' => $data])->execute();
   }
 
   protected function update($name, $data) {
diff -u b/core/tests/Drupal/KernelTests/Core/Database/RegressionTest.php b/core/tests/Drupal/KernelTests/Core/Database/RegressionTest.php
--- b/core/tests/Drupal/KernelTests/Core/Database/RegressionTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Database/RegressionTest.php
@@ -2,6 +2,8 @@
 
 namespace Drupal\KernelTests\Core\Database;
 
+use Drupal\Core\Database\Database;
+
 /**
  * Regression tests cases for the database layer.
  *
@@ -70,7 +72,7 @@
    * @expectedDeprecation db_set_active() is deprecated in Drupal 8.0.x and will be removed before Drupal 9.0.0. Use \Drupal\Core\Database\Database::setActiveConnection() instead. See https://www.drupal.org/node/2944084.
    */
   public function testDBIsActive() {
-    $get_active_db = $this->connection->getKey();
+    $get_active_db = Database::getConnection()->getKey();
     $this->assert(db_set_active($get_active_db), 'Database connection is active');
   }
 
@@ -87,17 +89,2 @@
 
-  /**
-   * Tests the db_insert() function.
-   *
-   * @group legacy
-   *
-   * @expectedDeprecation db_insert() is deprecated in Drupal 8.0.x and will be removed before Drupal 9.0.0. Use \Drupal\Core\Database\Database::getConnection()->insert() instead. See https://www.drupal.org/node/2989742
-   */
-  public function testDbInsert() {
-    $this->assertNotNull(
-      db_insert('test')
-        ->fields(['name' => 'Tester', 'age' => 20])
-        ->execute()
-    );
-  }
-
 }
diff -u b/core/tests/Drupal/KernelTests/Core/Entity/FieldSqlStorageTest.php b/core/tests/Drupal/KernelTests/Core/Entity/FieldSqlStorageTest.php
--- b/core/tests/Drupal/KernelTests/Core/Entity/FieldSqlStorageTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/FieldSqlStorageTest.php
@@ -123,7 +123,8 @@
 
     // Generate values and insert them directly in the storage tables.
     $values = [];
-    $query = Database::getConnection()->insert($this->revisionTable)->fields($columns);
+    $connection = Database::getConnection();
+    $query = $connection->insert($this->revisionTable)->fields($columns);
     foreach ($revision_ids as $revision_id) {
       // Put one value too many.
       for ($delta = 0; $delta <= $this->fieldCardinality; $delta++) {
@@ -133,7 +134,7 @@
       }
       $query->execute();
     }
-    $query = Database::getConnection()->insert($this->table)->fields($columns);
+    $query = $connection->insert($this->table)->fields($columns);
     foreach ($values[$revision_id] as $delta => $value) {
       $query->values([$bundle, 0, $entity->id(), $revision_id, $delta, $entity->language()->getId(), $value]);
     }
@@ -167,8 +168,8 @@
     // loaded.
     $unavailable_langcode = 'xx';
     $values = [$bundle, 0, $entity->id(), $entity->getRevisionId(), 0, $unavailable_langcode, mt_rand(1, 127)];
-    Database::getConnection()->insert($this->table)->fields($columns)->values($values)->execute();
-    Database::getConnection()->insert($this->revisionTable)->fields($columns)->values($values)->execute();
+    $connection->insert($this->table)->fields($columns)->values($values)->execute();
+    $connection->insert($this->revisionTable)->fields($columns)->values($values)->execute();
     $entity = $storage->load($entity->id());
     $this->assertFalse(array_key_exists($unavailable_langcode, $entity->{$this->fieldName}));
   }
only in patch2:
unchanged:
--- a/core/tests/Drupal/KernelTests/Core/Database/DatabaseLegacyTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Database/DatabaseLegacyTest.php
@@ -3,6 +3,7 @@
 namespace Drupal\KernelTests\Core\Database;
 
 use Drupal\Core\Database\Query\Condition;
+use Drupal\Core\Database\Query\Insert;
 use Drupal\Core\Database\Query\Update;
 use Drupal\Core\Database\Transaction;
 use Drupal\Core\Database\Database;
@@ -216,4 +217,13 @@ public function testDbUpdate() {
     $this->assertInstanceOf(Update::class, db_update('test'));
   }
 
+  /**
+   * Tests the db_insert() function.
+   *
+   * @expectedDeprecation db_insert() is deprecated in Drupal 8.0.x and will be removed before Drupal 9.0.0. Instead, get a database connection injected into your service from the container and call call insert() on it. For example, $injected_database->insert($table, $options); See https://www.drupal.org/node/2993033
+   */
+  public function testDbInsert() {
+    $this->assertInstanceOf(Insert::class, db_insert('test'));
+  }
+
 }