diff --git a/core/includes/database.inc b/core/includes/database.inc
index 9f0f9939d74b5f99d668ecada1ec55f2b8581db5..bd6e32572c369d4c6a43a2588af3ab2f47361f1f 100644
--- a/core/includes/database.inc
+++ b/core/includes/database.inc
@@ -21,11 +21,12 @@
  * Executes an arbitrary query string against the active database.
  *
  * Use this function for SELECT queries if it is just a simple query string.
- * If the caller or other modules need to change the query, use db_select()
- * instead.
+ * If the caller or other modules need to change the query, use
+ * \Drupal::database()->select() instead.
  *
  * Do not use this function for INSERT, UPDATE, or DELETE queries. Those should
- * be handled via db_insert(), db_update() and db_delete() respectively.
+ * be handled via \Drupal::database()->insert(), \Drupal::database()->update(),
+ * \Drupal::database()->merge()and \Drupal::database()->delete().
  *
  * @param string|\Drupal\Core\Database\StatementInterface $query
  *   The prepared statement query to run. Although it will accept both named and
@@ -382,14 +383,15 @@ function db_escape_field($field) {
  * a backslash. Use this to do a search for a verbatim string without any
  * wildcard behavior.
  *
- * You must use a query builder like db_select() in order to use db_like() on
- * all supported database systems. Using db_like() with db_query() or
- * db_query_range() is not supported.
+ * You must use a query builder like \Drupal::database()->select() in order to
+ * use \Drupal::database()->escapeLike() on all supported database systems. Using
+ * \Drupal::database()->escapeLike() with \Drupal::database()->query() or
+ * \Drupal::database()->queryRange() is not supported.
  *
  * For example, the following does a case-insensitive query for all rows whose
  * name starts with $prefix:
  * @code
- * $result = db_select('person', 'p')
+ * $result = \Drupal::database()->select('person', 'p')
  *   ->fields('p')
  *   ->condition('name', db_like($prefix) . '%', 'LIKE')
  *   ->execute()
@@ -1050,8 +1052,8 @@ function db_drop_index($table, $name) {
  * recreate all indices and primary keys that are using the changed field.
  *
  * That means that you have to drop all affected keys and indexes with
- * db_drop_{primary_key,unique_key,index}() before calling
- * \Drupal\Core\Database\Schema::changeField().
+ * \Drupal::database()->schema()->drop{PrimaryKey,UniqueKey,Index}() before
+ * calling \Drupal\Core\Database\Schema::changeField().
  * To recreate the keys and indices, pass the key definitions as the optional
  * $keys_new argument directly to \Drupal\Core\Database\Schema::changeField().
  *
@@ -1082,14 +1084,15 @@ function db_drop_index($table, $name) {
  *
  * On MySQL, all type 'serial' fields must be part of at least one key or index
  * as soon as they are created. You cannot use
- * db_add_{primary_key,unique_key,index}() for this purpose because the ALTER
- * TABLE command will fail to add the column without a key or index
- * specification. The solution is to use the optional $keys_new argument to
- * create the key or index at the same time as field.
- *
- * You could use db_add_{primary_key,unique_key,index}() in all cases unless you
- * are converting a field to be type serial. You can use the $keys_new argument
- * in all cases.
+ * \Drupal::database()->schema()->add{PrimaryKey,UniqueKey,Index}() for this
+ * purpose because the ALTER TABLE command will fail to add the column without
+ * a key or index specification. The solution is to use the optional $keys_new
+ * argument to create the key or index at the same time as field.
+ *
+ * You could use
+ * \Drupal::database()->schema()->add{PrimaryKey,UniqueKey,Index}() in all
+ * cases unless you are converting a field to be type serial. You can use the
+ * $keys_new argument in all cases.
  *
  * @param $table
  *   Name of the table.
diff --git a/core/includes/form.inc b/core/includes/form.inc
index bd256ad16279f22675194e455ec64431be0cc8af..fefa9b3b872b575244af6c8195f6f786c83ab8ff 100644
--- a/core/includes/form.inc
+++ b/core/includes/form.inc
@@ -630,7 +630,7 @@ function template_preprocess_form_element_label(&$variables) {
  *       ->fetchField();
  *   }
  *   $limit = 5;
- *   $result = db_select('example')
+ *   $result = \Drupal::database()->select('example')
  *     ->fields('example', array('id'))
  *     ->condition('id', $context['sandbox']['current_id'], '>')
  *     ->orderBy('id')
diff --git a/core/includes/pager.inc b/core/includes/pager.inc
index 4c588419f66e07981c5ecd939d1971f64e87c178..81daa34c6e53d840bd9321b060206b339946a1cc 100644
--- a/core/includes/pager.inc
+++ b/core/includes/pager.inc
@@ -50,7 +50,7 @@ function pager_find_page($element = 0) {
  * can simply extend the query object with the 'PagerSelectExtender' extender
  * before executing it. For example:
  * @code
- *   $query = db_select('some_table')
+ *   $query = \Drupal::database()->select('some_table')
  *     ->extend('Drupal\Core\Database\Query\PagerSelectExtender');
  * @endcode
  *
diff --git a/core/lib/Drupal/Core/Database/Driver/pgsql/Select.php b/core/lib/Drupal/Core/Database/Driver/pgsql/Select.php
index e76cb0f9522e15188bb96a545e744b5dfe2102a6..2df730d6139c7f05f8828f415c344abb92b517ee 100644
--- a/core/lib/Drupal/Core/Database/Driver/pgsql/Select.php
+++ b/core/lib/Drupal/Core/Database/Driver/pgsql/Select.php
@@ -30,7 +30,7 @@ public function orderRandom() {
    * yet selected.
    *
    * @code
-   *   $query = db_select('example', 'e');
+   *   $query = \Drupal::database()->select('example', 'e');
    *   $query->join('example_revision', 'er', 'e.vid = er.vid');
    *   $query
    *     ->distinct()
diff --git a/core/lib/Drupal/Core/Database/Driver/sqlite/Schema.php b/core/lib/Drupal/Core/Database/Driver/sqlite/Schema.php
index 51c8686c3831662542d6cbe0e4eb542118ef47db..c6f34c5c241f31e3f521839f1e68ddb2c67bc031 100644
--- a/core/lib/Drupal/Core/Database/Driver/sqlite/Schema.php
+++ b/core/lib/Drupal/Core/Database/Driver/sqlite/Schema.php
@@ -157,7 +157,7 @@ protected function processField($field) {
    * Create an SQL string for a field to be used in table creation or alteration.
    *
    * Before passing a field out of a schema definition into this function it has
-   * to be processed by db_processField().
+   * to be processed by self::processField().
    *
    * @param $name
    *   Name of the field.
diff --git a/core/lib/Drupal/Core/Database/Query/ConditionInterface.php b/core/lib/Drupal/Core/Database/Query/ConditionInterface.php
index 12e99682b6291d877f28fffc5e217087263742ed..fe5140c2af42b32fa70d1b6bbcecbb551f140172 100644
--- a/core/lib/Drupal/Core/Database/Query/ConditionInterface.php
+++ b/core/lib/Drupal/Core/Database/Query/ConditionInterface.php
@@ -30,7 +30,7 @@ interface ConditionInterface {
    * Drupal considers LIKE case insensitive and the following is often used
    * to tell the database that case insensitive equivalence is desired:
    * @code
-   * db_select('users')
+   * \Drupal::database()->select('users')
    *  ->condition('name', $injected_connection->escapeLike($name), 'LIKE')
    * @endcode
    * Use 'LIKE BINARY' instead of 'LIKE' for case sensitive queries.
diff --git a/core/lib/Drupal/Core/Database/Schema.php b/core/lib/Drupal/Core/Database/Schema.php
index f32d9fb289e7df1ed9c5766fc41cef7c8c170cf9..ad5067789266f58ea84c403a96053a9f504aba6e 100644
--- a/core/lib/Drupal/Core/Database/Schema.php
+++ b/core/lib/Drupal/Core/Database/Schema.php
@@ -171,7 +171,7 @@ public function tableExists($table) {
     $condition->compile($this->connection, $this);
     // Normally, we would heartily discourage the use of string
     // concatenation for conditionals like this however, we
-    // couldn't use db_select() here because it would prefix
+    // couldn't use \Drupal::database()->select() here because it would prefix
     // information_schema.tables and the query would fail.
     // Don't use {} around information_schema.tables table.
     return (bool) $this->connection->query("SELECT 1 FROM information_schema.tables WHERE " . (string) $condition, $condition->arguments())->fetchField();
@@ -198,7 +198,7 @@ public function findTables($table_expression) {
     $tables = [];
     // Normally, we would heartily discourage the use of string
     // concatenation for conditionals like this however, we
-    // couldn't use db_select() here because it would prefix
+    // couldn't use \Drupal::database()->select() here because it would prefix
     // information_schema.tables and the query would fail.
     // Don't use {} around information_schema.tables table.
     $results = $this->connection->query("SELECT table_name as table_name FROM information_schema.tables WHERE " . (string) $condition, $condition->arguments());
@@ -253,7 +253,7 @@ public function fieldExists($table, $column) {
     $condition->compile($this->connection, $this);
     // Normally, we would heartily discourage the use of string
     // concatenation for conditionals like this however, we
-    // couldn't use db_select() here because it would prefix
+    // couldn't use \Drupal::database()->select() here because it would prefix
     // information_schema.tables and the query would fail.
     // Don't use {} around information_schema.columns table.
     return (bool) $this->connection->query("SELECT 1 FROM information_schema.columns WHERE " . (string) $condition, $condition->arguments())->fetchField();
diff --git a/core/lib/Drupal/Core/Database/database.api.php b/core/lib/Drupal/Core/Database/database.api.php
index c39cf78cf4a9f9d7c15182fa4d952b189b78e985..82b6408669ae269846978bed5b5c35960f99ea1a 100644
--- a/core/lib/Drupal/Core/Database/database.api.php
+++ b/core/lib/Drupal/Core/Database/database.api.php
@@ -93,6 +93,11 @@
  * fields (see the @link entity_api Entity API topic @endlink for more on
  * entity queries).
  *
+ * Note: \Drupal::database() is used here as a shorthand way to get a reference
+ * to the database connection object. In most classes, you should use dependency
+ * injection and inject the 'database' service to perform queries. See
+ * @ref sec_connection below for details.
+ *
  * The dynamic query API lets you build up a query dynamically using method
  * calls. As an illustration, the query example from @ref sec_simple above
  * would be:
diff --git a/core/modules/node/tests/src/Kernel/NodeAccessLanguageAwareCombinationTest.php b/core/modules/node/tests/src/Kernel/NodeAccessLanguageAwareCombinationTest.php
index b3a84d23ece0818553eff6a62843ab2a69d0abaf..6886f22db6d8a90240446037d0ebb9883978b192 100644
--- a/core/modules/node/tests/src/Kernel/NodeAccessLanguageAwareCombinationTest.php
+++ b/core/modules/node/tests/src/Kernel/NodeAccessLanguageAwareCombinationTest.php
@@ -262,7 +262,7 @@ public function testNodeAccessLanguageAwareCombination() {
 
     // Four nodes should be returned with public Hungarian translations or the
     // no language public node.
-    $this->assertEqual(count($nids), 4, 'db_select() returns 4 nodes when no langcode is specified.');
+    $this->assertEqual(count($nids), 4, 'Query returns 4 nodes when no langcode is specified.');
     $this->assertTrue(array_key_exists($this->nodes['public_both_public']->id(), $nids), 'Returned node ID is full public node.');
     $this->assertTrue(array_key_exists($this->nodes['public_ca_private']->id(), $nids), 'Returned node ID is Hungarian public only node.');
     $this->assertTrue(array_key_exists($this->nodes['private_both_public']->id(), $nids), 'Returned node ID is both public non-language-aware private only node.');
@@ -277,7 +277,7 @@ public function testNodeAccessLanguageAwareCombination() {
     $nids = $select->execute()->fetchAllAssoc('nid');
 
     // Three nodes should be returned (with public Hungarian translations).
-    $this->assertEqual(count($nids), 3, 'db_select() returns 3 nodes.');
+    $this->assertEqual(count($nids), 3, 'Query returns 3 nodes.');
     $this->assertTrue(array_key_exists($this->nodes['public_both_public']->id(), $nids), 'Returned node ID is both public node.');
     $this->assertTrue(array_key_exists($this->nodes['public_ca_private']->id(), $nids), 'Returned node ID is Hungarian public only node.');
     $this->assertTrue(array_key_exists($this->nodes['private_both_public']->id(), $nids), 'Returned node ID is both public non-language-aware private only node.');
@@ -291,7 +291,7 @@ public function testNodeAccessLanguageAwareCombination() {
     $nids = $select->execute()->fetchAllAssoc('nid');
 
     // Three nodes should be returned (with public Catalan translations).
-    $this->assertEqual(count($nids), 3, 'db_select() returns 3 nodes.');
+    $this->assertEqual(count($nids), 3, 'Query returns 3 nodes.');
     $this->assertTrue(array_key_exists($this->nodes['public_both_public']->id(), $nids), 'Returned node ID is both public node.');
     $this->assertTrue(array_key_exists($this->nodes['public_hu_private']->id(), $nids), 'Returned node ID is Catalan public only node.');
     $this->assertTrue(array_key_exists($this->nodes['private_both_public']->id(), $nids), 'Returned node ID is both public non-language-aware private only node.');
@@ -305,7 +305,7 @@ public function testNodeAccessLanguageAwareCombination() {
     $nids = $select->execute()->fetchAllAssoc('nid');
 
     // There are no nodes with German translations, so no results are returned.
-    $this->assertTrue(empty($nids), 'db_select() returns an empty result.');
+    $this->assertTrue(empty($nids), 'Query returns an empty result.');
 
     // Query the nodes table as admin user (full access) with the node access
     // tag and no specific langcode.
@@ -316,7 +316,7 @@ public function testNodeAccessLanguageAwareCombination() {
     $nids = $select->execute()->fetchAllAssoc('nid');
 
     // All nodes are returned.
-    $this->assertEqual(count($nids), 10, 'db_select() returns all nodes.');
+    $this->assertEqual(count($nids), 10, 'Query returns all nodes.');
 
     // Query the nodes table as admin user (full access) with the node access
     // tag and langcode de.
@@ -329,7 +329,7 @@ public function testNodeAccessLanguageAwareCombination() {
 
     // Even though there is no German translation, all nodes are returned
     // because node access filtering does not occur when the user is user 1.
-    $this->assertEqual(count($nids), 10, 'db_select() returns all nodes.');
+    $this->assertEqual(count($nids), 10, 'Query returns all nodes.');
   }
 
 }
diff --git a/core/modules/node/tests/src/Kernel/NodeAccessLanguageAwareTest.php b/core/modules/node/tests/src/Kernel/NodeAccessLanguageAwareTest.php
index 919ae2cd1e28c9d81c513cb3ede4057e87ea4747..2576060efe1e28dc032476499459ac05f2be7795 100644
--- a/core/modules/node/tests/src/Kernel/NodeAccessLanguageAwareTest.php
+++ b/core/modules/node/tests/src/Kernel/NodeAccessLanguageAwareTest.php
@@ -10,7 +10,7 @@
 use Drupal\field\Entity\FieldStorageConfig;
 
 /**
- * Tests node_access and db_select() with node_access tag functionality with
+ * Tests node_access and select queries with node_access tag functionality with
  * multiple languages with node_access_test_language which is language-aware.
  *
  * @group node
@@ -220,7 +220,7 @@ public function testNodeAccessLanguageAware() {
 
     // Two nodes should be returned: the node with both translations public, and
     // the node with only the Catalan translation marked as private.
-    $this->assertEqual(count($nids), 2, 'db_select() returns 2 nodes when the hu langcode is specified.');
+    $this->assertEqual(count($nids), 2, 'Query returns 2 nodes when the hu langcode is specified.');
     $this->assertTrue(array_key_exists($this->nodes['both_public']->id(), $nids), 'The node with both translations public is returned.');
     $this->assertTrue(array_key_exists($this->nodes['ca_private']->id(), $nids), 'The node with only the Catalan translation private is returned.');
 
@@ -234,7 +234,7 @@ public function testNodeAccessLanguageAware() {
 
     // Two nodes should be returned: the node with both translations public, and
     // the node with only the Hungarian translation marked as private.
-    $this->assertEqual(count($nids), 2, 'db_select() returns 2 nodes when the hu langcode is specified.');
+    $this->assertEqual(count($nids), 2, 'Query returns 2 nodes when the hu langcode is specified.');
     $this->assertTrue(array_key_exists($this->nodes['both_public']->id(), $nids), 'The node with both translations public is returned.');
     $this->assertTrue(array_key_exists($this->nodes['hu_private']->id(), $nids), 'The node with only the Hungarian translation private is returned.');
 
@@ -247,7 +247,7 @@ public function testNodeAccessLanguageAware() {
     $nids = $select->execute()->fetchAllAssoc('nid');
 
     // There are no nodes with German translations, so no results are returned.
-    $this->assertTrue(empty($nids), 'db_select() returns an empty result when the de langcode is specified.');
+    $this->assertTrue(empty($nids), 'Query returns an empty result when the de langcode is specified.');
 
     // Query the nodes table as admin user (full access) with the node access
     // tag and no specific langcode.
@@ -258,7 +258,7 @@ public function testNodeAccessLanguageAware() {
     $nids = $select->execute()->fetchAllAssoc('nid');
 
     // All nodes are returned.
-    $this->assertEqual(count($nids), 6, 'db_select() returns all nodes.');
+    $this->assertEqual(count($nids), 6, 'Query returns all nodes.');
 
     // Query the nodes table as admin user (full access) with the node access
     // tag and langcode de.
@@ -271,7 +271,7 @@ public function testNodeAccessLanguageAware() {
 
     // Even though there is no German translation, all nodes are returned
     // because node access filtering does not occur when the user is user 1.
-    $this->assertEqual(count($nids), 6, 'db_select() returns all nodes.');
+    $this->assertEqual(count($nids), 6, 'Query returns all nodes.');
   }
 
 }
diff --git a/core/modules/node/tests/src/Kernel/NodeAccessLanguageTest.php b/core/modules/node/tests/src/Kernel/NodeAccessLanguageTest.php
index 06709021c628c2a5c2c0283c7a61ebd46ddf8e1a..269240670b9e19fd890e23b3e1e295f165a40dd7 100644
--- a/core/modules/node/tests/src/Kernel/NodeAccessLanguageTest.php
+++ b/core/modules/node/tests/src/Kernel/NodeAccessLanguageTest.php
@@ -9,7 +9,7 @@
 use Drupal\user\Entity\User;
 
 /**
- * Tests node_access and db_select() with node_access tag functionality with
+ * Tests node_access and select queries with node_access tag functionality with
  * multiple languages with a test node access module that is not language-aware.
  *
  * @group node
@@ -175,7 +175,7 @@ public function testNodeAccessPrivate() {
   }
 
   /**
-   * Tests db_select() with a 'node_access' tag and langcode metadata.
+   * Tests select queries with a 'node_access' tag and langcode metadata.
    */
   public function testNodeAccessQueryTag() {
     // Create a normal authenticated user.
@@ -214,7 +214,7 @@ public function testNodeAccessQueryTag() {
 
     // The public node and no language node should be returned. Because no
     // langcode is given it will use the fallback node.
-    $this->assertEqual(count($nids), 2, 'db_select() returns 2 node');
+    $this->assertEqual(count($nids), 2, 'Query returns 2 node');
     $this->assertTrue(array_key_exists($node_public->id(), $nids), 'Returned node ID is public node.');
     $this->assertTrue(array_key_exists($node_no_language->id(), $nids), 'Returned node ID is no language node.');
 
@@ -228,7 +228,7 @@ public function testNodeAccessQueryTag() {
     $nids = $select->execute()->fetchAllAssoc('nid');
 
     // Because no nodes are created in German, no nodes are returned.
-    $this->assertTrue(empty($nids), 'db_select() returns an empty result.');
+    $this->assertTrue(empty($nids), 'Query returns an empty result.');
 
     // Query the nodes table as admin user (full access) with the node access
     // tag and no specific langcode.
@@ -239,7 +239,7 @@ public function testNodeAccessQueryTag() {
     $nids = $select->execute()->fetchAllAssoc('nid');
 
     // All nodes are returned.
-    $this->assertEqual(count($nids), 3, 'db_select() returns all three nodes.');
+    $this->assertEqual(count($nids), 3, 'Query returns all three nodes.');
 
     // Query the nodes table as admin user (full access) with the node access
     // tag and langcode de.
@@ -252,7 +252,7 @@ public function testNodeAccessQueryTag() {
 
     // All nodes are returned because node access tag is not invoked when the
     // user is user 1.
-    $this->assertEqual(count($nids), 3, 'db_select() returns all three nodes.');
+    $this->assertEqual(count($nids), 3, 'Query returns all three nodes.');
   }
 
 }
diff --git a/core/modules/system/tests/src/Functional/Database/TemporaryQueryTest.php b/core/modules/system/tests/src/Functional/Database/TemporaryQueryTest.php
index 3e2cf5259b917a1cedba4d12b216f2bff0d0b5ee..f44073571a8ced01a1e523adc3a80b6f750d276c 100644
--- a/core/modules/system/tests/src/Functional/Database/TemporaryQueryTest.php
+++ b/core/modules/system/tests/src/Functional/Database/TemporaryQueryTest.php
@@ -38,7 +38,7 @@ public function testTemporaryQuery() {
       $this->fail('The creation of the temporary table failed.');
     }
 
-    // Now try to run two db_query_temporary() in the same request.
+    // Now try to run two temporary queries in the same request.
     $table_name_test = $connection->queryTemporary('SELECT name FROM {test}', []);
     $table_name_task = $connection->queryTemporary('SELECT pid FROM {test_task}', []);
 
diff --git a/core/modules/views/src/Plugin/views/display/DefaultDisplay.php b/core/modules/views/src/Plugin/views/display/DefaultDisplay.php
index 2d14cfb16cf4289f1c80427e56b778f853b4f13e..2b5b3f291b6c1439f9418a8bc2431d339dbbe0b8 100644
--- a/core/modules/views/src/Plugin/views/display/DefaultDisplay.php
+++ b/core/modules/views/src/Plugin/views/display/DefaultDisplay.php
@@ -51,7 +51,7 @@ public function isDefaultDisplay() {
    *
    * If short circuited at any point, look in $view->build_info for
    * information about the query. After execute, look in $view->result
-   * for the array of objects returned from db_query.
+   * for the array of objects returned from \Drupal::database()->query().
    *
    * You can also do:
    * @code
diff --git a/core/tests/Drupal/KernelTests/Core/Database/RegressionTest.php b/core/tests/Drupal/KernelTests/Core/Database/RegressionTest.php
index c5d05a2211a57f306ffc1b0357bb61d6613ef49e..5b501d95b47790ca91ab1117eb9277a3e2f4a5c0 100644
--- a/core/tests/Drupal/KernelTests/Core/Database/RegressionTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Database/RegressionTest.php
@@ -35,7 +35,7 @@ public function testRegression_310447() {
   }
 
   /**
-   * Tests the db_table_exists() function.
+   * Tests the Schema::tableExists() method.
    */
   public function testDBTableExists() {
     $this->assertSame(TRUE, $this->connection->schema()->tableExists('test'), 'Returns true for existent table.');