diff --git a/core/modules/book/book.services.yml b/core/modules/book/book.services.yml
index 8dc0ec4..a2977f8 100644
--- a/core/modules/book/book.services.yml
+++ b/core/modules/book/book.services.yml
@@ -6,14 +6,16 @@ services:
       - { name: breadcrumb_builder, priority: 701 }
   book.manager:
     class: Drupal\book\BookManager
-    arguments: ['@database', '@entity.manager', '@string_translation', '@config.factory']
+    arguments: ['@database', '@entity.manager', '@string_translation', '@config.factory', '@book.storage']
   book.outline:
     class: Drupal\book\BookOutline
     arguments: ['@book.manager']
   book.export:
     class: Drupal\book\BookExport
     arguments: ['@entity.manager', '@book.manager']
-
+  book.storage:
+    class: Drupal\book\BookStorage
+    arguments: ['@database']
   access_check.book.removable:
     class: Drupal\book\Access\BookNodeIsRemovableAccessCheck
     arguments: ['@book.manager']
diff --git a/core/modules/book/src/BookManager.php b/core/modules/book/src/BookManager.php
index c491cf4..e3504d9 100644
--- a/core/modules/book/src/BookManager.php
+++ b/core/modules/book/src/BookManager.php
@@ -57,6 +57,13 @@ class BookManager implements BookManagerInterface {
   protected $books;
 
   /**
+   * Book Storage.
+   *
+   * @var \Drupal\book\BookStorageInterface
+   */
+  protected $bookStorage;
+
+  /**
    * Stores flattened book trees.
    *
    * @var array
@@ -66,11 +73,12 @@ class BookManager implements BookManagerInterface {
   /**
    * Constructs a BookManager object.
    */
-  public function __construct(Connection $connection, EntityManagerInterface $entity_manager, TranslationInterface $translation, ConfigFactoryInterface $config_factory) {
+  public function __construct(Connection $connection, EntityManagerInterface $entity_manager, TranslationInterface $translation, ConfigFactoryInterface $config_factory, BookStorageInterface $book_storage) {
     $this->connection = $connection;
     $this->entityManager = $entity_manager;
     $this->stringTranslation = $translation;
     $this->configFactory = $config_factory;
+    $this->bookStorage = $book_storage;
   }
 
   /**
@@ -88,16 +96,10 @@ public function getAllBooks() {
    */
   protected function loadBooks() {
     $this->books = array();
-    $nids = $this->connection->query("SELECT DISTINCT(bid) FROM {book}")->fetchCol();
+    $nids = $this->bookStorage->getBooks();
 
     if ($nids) {
-      $query = $this->connection->select('book', 'b', array('fetch' => \PDO::FETCH_ASSOC));
-      $query->fields('b');
-      $query->condition('b.nid', $nids);
-      $query->addTag('node_access');
-      $query->addMetaData('base_table', 'book');
-      $book_links = $query->execute();
-
+      $book_links = $this->bookStorage->loadMultiple($nids);
       $nodes = $this->entityManager->getStorage('node')->loadMultiple($nids);
       // @todo: Sort by weight and translated title.
 
@@ -147,21 +149,7 @@ public function getParentDepthLimit(array $book_link) {
    *   the passed book link.
    */
   protected function findChildrenRelativeDepth(array $book_link) {
-    $query = $this->connection->select('book');
-    $query->addField('book', 'depth');
-    $query->condition('bid', $book_link['bid']);
-    $query->orderBy('depth', 'DESC');
-    $query->range(0, 1);
-
-    $i = 1;
-    $p = 'p1';
-    while ($i <= static::BOOK_MAX_DEPTH && $book_link[$p]) {
-      $query->condition($p, $book_link[$p]);
-      $p = 'p' . ++$i;
-    }
-
-    $max_depth = $query->execute()->fetchField();
-
+    $max_depth = $this->bookStorage->getChildRelativeDepth($book_link, static::BOOK_MAX_DEPTH);
     return ($max_depth > $book_link['depth']) ? $max_depth - $book_link['depth'] : 0;
   }
 
@@ -435,14 +423,12 @@ public function getTableOfContents($bid, $depth_limit, array $exclude = array())
    */
   public function deleteFromBook($nid) {
     $original = $this->loadBookLink($nid, FALSE);
-    $this->connection->delete('book')
-      ->condition('nid', $nid)
-      ->execute();
+    $this->bookStorage->delete($nid);
+
     if ($nid == $original['bid']) {
       // Handle deletion of a top-level post.
-      $result = $this->connection->query("SELECT * FROM {book} WHERE pid = :nid", array(
-        ':nid' => $nid
-      ))->fetchAllAssoc('nid', \PDO::FETCH_ASSOC);
+      $result = $this->bookStorage->loadBookChildren($nid);
+
       foreach ($result as $child) {
         $child['bid'] = $child['nid'];
         $this->updateOutline($child);
@@ -629,32 +615,11 @@ protected function doBookTreeBuild($bid, array $parameters = array()) {
     }
 
     if (!isset($trees[$tree_cid])) {
-      $query = $this->connection->select('book');
-      $query->fields('book');
-      for ($i = 1; $i <= static::BOOK_MAX_DEPTH; $i++) {
-        $query->orderBy('p' . $i, 'ASC');
-      }
-      $query->condition('bid', $bid);
-      if (!empty($parameters['expanded'])) {
-        $query->condition('pid', $parameters['expanded'], 'IN');
-      }
       $min_depth = (isset($parameters['min_depth']) ? $parameters['min_depth'] : 1);
-      if ($min_depth != 1) {
-        $query->condition('depth', $min_depth, '>=');
-      }
-      if (isset($parameters['max_depth'])) {
-        $query->condition('depth', $parameters['max_depth'], '<=');
-      }
-      // Add custom query conditions, if any were passed.
-      if (isset($parameters['conditions'])) {
-        foreach ($parameters['conditions'] as $column => $value) {
-          $query->condition($column, $value);
-        }
-      }
+      $result = $this->bookStorage->getBookMenuTree($bid, $parameters, $min_depth, static::BOOK_MAX_DEPTH);
 
       // Build an ordered array of links using the query result object.
       $links = array();
-      $result = $query->execute();
       foreach ($result as $link) {
         $link = (array) $link;
         $links[$link['nid']] = $link;
@@ -733,7 +698,7 @@ public function loadBookLink($nid, $translate = TRUE) {
    * {@inheritdoc}
    */
   public function loadBookLinks($nids, $translate = TRUE) {
-    $result = $this->connection->query("SELECT * FROM {book} WHERE nid IN (:nids)", array(':nids' =>  $nids), array('fetch' => \PDO::FETCH_ASSOC));
+    $result = $this->bookStorage->loadMultiple($nids);
     $links = array();
     foreach ($result as $link) {
       if ($translate) {
@@ -754,14 +719,9 @@ public function saveBookLink(array $link, $new) {
     $link += $this->getLinkDefaults($link['nid']);
     if ($new) {
       // Insert new.
-      $this->connection->insert('book')
-        ->fields(array(
-            'nid' => $link['nid'],
-            'bid' => $link['bid'],
-            'pid' => $link['pid'],
-            'weight' => $link['weight'],
-          ) + $this->getBookParents($link, (array) $this->loadBookLink($link['pid'], FALSE)))
-        ->execute();
+      $parents = $this->getBookParents($link, (array) $this->loadBookLink($link['pid'], FALSE));
+      $this->bookStorage->insert($link, $parents);
+
       // Update the has_children status of the parent.
       $this->updateParent($link);
     }
@@ -796,10 +756,11 @@ public function saveBookLink(array $link, $new) {
         $this->updateParent($link);
       }
       // Update the weight and pid.
-      $query = $this->connection->update('book');
-      $query->fields(array('weight' => $link['weight'], 'pid' => $link['pid'], 'bid' => $link['bid']));
-      $query->condition('nid', $link['nid']);
-      $query->execute();
+      $this->bookStorage->update($link['nid'], array(
+        'weight' => $link['weight'],
+        'pid' => $link['pid'],
+        'bid' => $link['bid'],
+      ));
     }
     foreach ($affected_bids as $bid) {
       \Drupal::cache('data')->deleteTags(array('bid' => $bid));
@@ -816,10 +777,6 @@ public function saveBookLink(array $link, $new) {
    *   The original parent of $link.
    */
   protected function moveChildren(array $link, array $original) {
-    $query = $this->connection->update('book');
-
-    $query->fields(array('bid' => $link['bid']));
-
     $p = 'p1';
     $expressions = array();
     for ($i = 1; $i <= $link['depth']; $p = 'p' . ++$i) {
@@ -841,18 +798,8 @@ protected function moveChildren(array $link, array $original) {
       // @see http://dev.mysql.com/doc/refman/5.0/en/update.html
       $expressions = array_reverse($expressions);
     }
-    foreach ($expressions as $expression) {
-      $query->expression($expression[0], $expression[1], $expression[2]);
-    }
 
-    $query->expression('depth', 'depth + :depth', array(':depth' => $shift));
-    $query->condition('bid', $original['bid']);
-    $p = 'p1';
-    for ($i = 1; !empty($original[$p]); $p = 'p' . ++$i) {
-      $query->condition($p, $original[$p]);
-    }
-
-    $query->execute();
+    $this->bookStorage->updateMovedChildren($link['bid'], $original, $expressions, $shift);
   }
 
   /**
@@ -874,10 +821,7 @@ protected function updateParent(array $link) {
       // Nothing to update.
       return TRUE;
     }
-    $query = $this->connection->update('book');
-    $query->fields(array('has_children' => 1))
-      ->condition('nid', $link['pid']);
-    return $query->execute();
+    return $this->bookStorage->update($link['pid'], array('has_children' => 1));
   }
 
   /**
@@ -900,22 +844,13 @@ protected function updateOriginalParent(array $original) {
       return TRUE;
     }
     // Check if $original had at least one child.
-    $original_number_of_children = $this->connection->select('book', 'b')
-      ->condition('bid', $original['bid'])
-      ->condition('pid', $original['pid'])
-      ->condition('nid', $original['nid'], '<>')
-      ->countQuery()
-      ->execute()
-      ->fetchField();
+    $original_number_of_children = $this->bookStorage->countOriginalLinkChildren($original);
 
     $parent_has_children = ((bool) $original_number_of_children) ? 1 : 0;
     // Update the parent. If the original link did not have children, then the
     // parent now does not have children. If the original had children, then the
     // the parent has children now (still).
-    $query = $this->connection->update('book');
-    $query->fields(array('has_children' => $parent_has_children))
-        ->condition('nid', $original['pid']);
-    return $query->execute();
+    return $this->bookStorage->update($original['pid'], array('has_children' => $parent_has_children));
   }
 
   /**
@@ -948,15 +883,14 @@ public function bookTreeCheckAccess(&$tree, $node_links = array()) {
     if ($node_links) {
       // @todo Extract that into its own method.
       $nids = array_keys($node_links);
-      $select = $this->connection->select('node_field_data', 'n');
-      $select->addField('n', 'nid');
+
       // @todo This should be actually filtering on the desired node status field
       //   language and just fall back to the default language.
-      $select->condition('n.status', 1);
+      $nids = \Drupal::entityQuery('node')
+        ->condition('nid', $nids)
+        ->condition('status', 1)
+        ->execute();
 
-      $select->condition('n.nid', $nids, 'IN');
-      $select->addTag('node_access');
-      $nids = $select->execute()->fetchCol();
       foreach ($nids as $nid) {
         foreach ($node_links[$nid] as $mlid => $link) {
           $node_links[$nid][$mlid]['access'] = TRUE;
@@ -1102,17 +1036,9 @@ public function bookSubtreeData($link) {
 
       // If the subtree data was not in the cache, $data will be NULL.
       if (!isset($data)) {
-        $query = db_select('book', 'b', array('fetch' => \PDO::FETCH_ASSOC));
-        $query->fields('b');
-        $query->condition('b.bid', $link['bid']);
-        for ($i = 1; $i <= static::BOOK_MAX_DEPTH && $link["p$i"]; ++$i) {
-          $query->condition("p$i", $link["p$i"]);
-        }
-        for ($i = 1; $i <= static::BOOK_MAX_DEPTH; ++$i) {
-          $query->orderBy("p$i");
-        }
+        $result = $this->bookStorage->getBookSubtree($link, static::BOOK_MAX_DEPTH);
         $links = array();
-        foreach ($query->execute() as $item) {
+        foreach ($result as $item) {
           $links[] = $item;
         }
         $data['tree'] = $this->buildBookOutlineData($links, array(), $link['depth']);
diff --git a/core/modules/book/src/BookStorage.php b/core/modules/book/src/BookStorage.php
new file mode 100644
index 0000000..621932c
--- /dev/null
+++ b/core/modules/book/src/BookStorage.php
@@ -0,0 +1,193 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\book\BookStorage.
+ */
+
+namespace Drupal\book;
+
+use Drupal\Core\Database\Connection;
+
+/**
+ * Defines a storage class for books.
+ */
+class BookStorage implements BookStorageInterface {
+
+  /**
+   * Database Service Object.
+   *
+   * @var \Drupal\Core\Database\Connection
+   */
+  protected $connection;
+
+  /**
+   * Constructs a BookStorage object.
+   */
+  public function __construct(Connection $connection) {
+    $this->connection = $connection;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getBooks() {
+    return $this->connection->query("SELECT DISTINCT(bid) FROM {book}")->fetchCol();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function loadMultiple($nids) {
+    $query = $this->connection->select('book', 'b', array('fetch' => \PDO::FETCH_ASSOC));
+    $query->fields('b');
+    $query->condition('b.nid', $nids);
+    $query->addTag('node_access');
+    $query->addMetaData('base_table', 'book');
+    return $query->execute();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getChildRelativeDepth($book_link, $max_depth) {
+    $query = $this->connection->select('book');
+    $query->addField('book', 'depth');
+    $query->condition('bid', $book_link['bid']);
+    $query->orderBy('depth', 'DESC');
+    $query->range(0, 1);
+
+    $i = 1;
+    $p = 'p1';
+    while ($i <= $max_depth && $book_link[$p]) {
+      $query->condition($p, $book_link[$p]);
+      $p = 'p' . ++$i;
+    }
+
+    return $query->execute()->fetchField();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function delete($nid) {
+    return $this->connection->delete('book')
+      ->condition('nid', $nid)
+      ->execute();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function loadBookChildren($pid) {
+    return $this->connection
+      ->query("SELECT * FROM {book} WHERE pid = :pid", array(':pid' => $pid))
+      ->fetchAllAssoc('nid', \PDO::FETCH_ASSOC);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getBookMenuTree($bid, $parameters, $min_depth, $max_depth) {
+    $query = $this->connection->select('book');
+    $query->fields('book');
+    for ($i = 1; $i <= $max_depth; $i++) {
+      $query->orderBy('p' . $i, 'ASC');
+    }
+    $query->condition('bid', $bid);
+    if (!empty($parameters['expanded'])) {
+      $query->condition('pid', $parameters['expanded'], 'IN');
+    }
+    if ($min_depth != 1) {
+      $query->condition('depth', $min_depth, '>=');
+    }
+    if (isset($parameters['max_depth'])) {
+      $query->condition('depth', $parameters['max_depth'], '<=');
+    }
+    // Add custom query conditions, if any were passed.
+    if (isset($parameters['conditions'])) {
+      foreach ($parameters['conditions'] as $column => $value) {
+        $query->condition($column, $value);
+      }
+    }
+
+    return $query->execute();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function insert($link, $parents) {
+    return $this->connection
+      ->insert('book')
+      ->fields(array(
+        'nid' => $link['nid'],
+        'bid' => $link['bid'],
+        'pid' => $link['pid'],
+        'weight' => $link['weight'],
+        ) + $parents
+      )
+      ->execute();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function update($nid, $fields) {
+    return $this->connection
+      ->update('book')
+      ->fields($fields)
+      ->condition('nid', $nid)
+      ->execute();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function updateMovedChildren($bid, $original, $expressions, $shift) {
+    $query = $this->connection->update('book');
+    $query->fields(array('bid' => $bid));
+
+    foreach ($expressions as $expression) {
+      $query->expression($expression[0], $expression[1], $expression[2]);
+    }
+
+    $query->expression('depth', 'depth + :depth', array(':depth' => $shift));
+    $query->condition('bid', $original['bid']);
+    $p = 'p1';
+    for ($i = 1; !empty($original[$p]); $p = 'p' . ++$i) {
+      $query->condition($p, $original[$p]);
+    }
+
+    return $query->execute();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function countOriginalLinkChildren($original) {
+    return $this->connection->select('book', 'b')
+      ->condition('bid', $original['bid'])
+      ->condition('pid', $original['pid'])
+      ->condition('nid', $original['nid'], '<>')
+      ->countQuery()
+      ->execute()->fetchField();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getBookSubtree($link, $max_depth) {
+    $query = db_select('book', 'b', array('fetch' => \PDO::FETCH_ASSOC));
+    $query->fields('b');
+    $query->condition('b.bid', $link['bid']);
+
+    for ($i = 1; $i <= $max_depth && $link["p$i"]; ++$i) {
+      $query->condition("p$i", $link["p$i"]);
+    }
+    for ($i = 1; $i <= $max_depth; ++$i) {
+      $query->orderBy("p$i");
+    }
+    return $query->execute();
+  }
+}
diff --git a/core/modules/book/src/BookStorageInterface.php b/core/modules/book/src/BookStorageInterface.php
new file mode 100644
index 0000000..ea03893
--- /dev/null
+++ b/core/modules/book/src/BookStorageInterface.php
@@ -0,0 +1,156 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\book\BookStorageInterface.
+*/
+
+namespace Drupal\book;
+
+/**
+ * Defines a common interface for book storage classes.
+ */
+interface BookStorageInterface {
+
+  /**
+   * Gets books (the highest positioned book links).
+   *
+   * @return array
+   *   An array of book ids.
+   */
+  public function getBooks();
+
+  /**
+   * Loads books.
+   *
+   * @param array $nids
+   *   An array of nids.
+   *
+   * @return array
+   *   Array of loaded book items.
+   */
+  public function loadMultiple($nids);
+
+  /**
+   * Gets child relative depth.
+   *
+   * @param array $book_link
+   *   The book link.
+   *
+   * @param int $max_depth
+   *   The maximum supported depth of the book tree.
+   *
+   * @return int
+   *   The depth of the searched book.
+   */
+  public function getChildRelativeDepth($book_link, $max_depth);
+
+  /**
+   * Deletes a book entry.
+   *
+   * @param int $nid
+   *   Deletes a book entry.
+   *
+   * @return mixed
+   *   Number of deleted book entires.
+   */
+  public function delete($nid);
+
+  /**
+   * Loads book's children using it's parent's id.
+   *
+   * @param int $pid
+   *   The parent's book nid.
+   *
+   * @return array
+   *   Array of loaded book items.
+   */
+  public function loadBookChildren($pid);
+
+  /**
+   * Builds tree data used for the menu tree.
+   *
+   * @param int $bid
+   *   The ID of the book that we are building the tree for.
+   * @param array $parameters
+   *   An associative array of build parameters. For info about individual
+   *   parameters see BookManager::bookTreeBuild().
+   * @param int $min_depth
+   *   The minimum depth of book links in the resulting tree.
+   * @param int $max_depth
+   *   The maximum supported depth of the book tree.
+   *
+   * @return array
+   *   Array of loaded book links.
+   */
+  public function getBookMenuTree($bid, $parameters, $min_depth, $max_depth);
+
+  /**
+   * Inserts a book link.
+   *
+   * @param array $link
+   *   The link array to be inserted in the database.
+   * @param array $parents
+   *   The array of parent ids for the link to be inserted.
+   *
+   * @return mixed
+   *   The last insert ID of the query, if one exists.
+   */
+  public function insert($link, $parents);
+
+
+  /**
+   * Updates book reference for links that were moved between books.
+   *
+   * @param int $nid
+   *   The nid of the book entry to be updated.
+   * @param array $fields
+   *   The array of fields to be updated.
+   *
+   * @return mixed
+   *   The number of rows matched by the update query.
+   */
+  public function update($nid, $fields);
+
+  /**
+   * Update the book id of the book link that it's beeing moved.
+   *
+   * @param int $bid
+   *   The ID of the book whose children we move.
+   * @param array $original
+   *   The original parent of the book link.
+   * @param array $expressions
+   *   Array of expressions to be added to the query.
+   * @param int $shift
+   *   The difference in depth between the old and the new position of the
+   *   element being moved.
+   *
+   * @return mixed
+   *   The number of rows matched by the update query.
+   */
+  public function updateMovedChildren($bid, $original, $expressions, $shift);
+
+  /**
+   * Count the number of original link children.
+   *
+   * @param array $original
+   *   The book link array.
+   *
+   * @return int
+   *   Number of children.
+   */
+  public function countOriginalLinkChildren($original);
+
+  /**
+   * Get book subtree.
+   *
+   * @param array $link
+   *   A fully loaded book link.
+   * @param int $max_depth
+   *   The maximum supported depth of the book tree.
+   *
+   * @return array
+   *   Array of unordered subtree book items.
+   */
+  public function getBookSubtree($link, $max_depth);
+}
diff --git a/core/modules/book/src/Plugin/Block/BookNavigationBlock.php b/core/modules/book/src/Plugin/Block/BookNavigationBlock.php
index 5e85d99..d9bcdaf 100644
--- a/core/modules/book/src/Plugin/Block/BookNavigationBlock.php
+++ b/core/modules/book/src/Plugin/Block/BookNavigationBlock.php
@@ -148,11 +148,9 @@ public function build() {
     }
     elseif ($current_bid) {
       // Only display this block when the user is browsing a book.
-      $select = db_select('node', 'n')
-        ->fields('n', array('nid'))
-        ->condition('n.nid', $node->book['bid'])
-        ->addTag('node_access');
-      $nid = $select->execute()->fetchField();
+      $query = \Drupal::entityQuery('node');
+      $nid = $query->condition('nid', $node->book['bid'], '=')->execute();
+
       // Only show the block if the user has view access for the top-level node.
       if ($nid) {
         $tree = $this->bookManager->bookTreeAllData($node->book['bid'], $node->book);
diff --git a/core/modules/book/tests/src/BookManagerTest.php b/core/modules/book/tests/src/BookManagerTest.php
index 4abf063..a7e0964 100644
--- a/core/modules/book/tests/src/BookManagerTest.php
+++ b/core/modules/book/tests/src/BookManagerTest.php
@@ -52,6 +52,13 @@ class BookManagerTest extends UnitTestCase {
   protected $bookManager;
 
   /**
+   * Book Storage.
+   *
+   * @var \Drupal\book\BookStorageInterface
+   */
+  protected $bookStorage;
+
+  /**
    * {@inheritdoc}
    */
   protected function setUp() {
@@ -61,7 +68,8 @@ protected function setUp() {
     $this->entityManager = $this->getMock('Drupal\Core\Entity\EntityManagerInterface');
     $this->translation = $this->getStringTranslationStub();
     $this->configFactory = $this->getConfigFactoryStub(array());
-    $this->bookManager = new BookManager($this->connection, $this->entityManager, $this->translation, $this->configFactory);
+    $this->bookStorage = $this->getMock('Drupal\book\BookStorageInterface');
+    $this->bookManager = new BookManager($this->connection, $this->entityManager, $this->translation, $this->configFactory, $this->bookStorage);
   }
 
   /**