diff --git a/core/lib/Drupal/Core/Database/Query/Delete.php b/core/lib/Drupal/Core/Database/Query/Delete.php
index 08e7af1..1f59dd9 100644
--- a/core/lib/Drupal/Core/Database/Query/Delete.php
+++ b/core/lib/Drupal/Core/Database/Query/Delete.php
@@ -17,6 +17,8 @@
  */
 class Delete extends Query implements ConditionInterface {
 
+  use QueryConditionTrait;
+
   /**
    * The table from which to delete.
    *
@@ -25,15 +27,6 @@ class Delete extends Query implements ConditionInterface {
   protected $table;
 
   /**
-   * The condition object for this query.
-   *
-   * Condition handling is handled via composition.
-   *
-   * @var Condition
-   */
-  protected $condition;
-
-  /**
    * Constructs a Delete object.
    *
    * @param \Drupal\Core\Database\Connection $connection
@@ -52,82 +45,6 @@ public function __construct(Connection $connection, $table, array $options = arr
   }
 
   /**
-   * Implements Drupal\Core\Database\Query\ConditionInterface::condition().
-   */
-  public function condition($field, $value = NULL, $operator = '=') {
-    $this->condition->condition($field, $value, $operator);
-    return $this;
-  }
-
-  /**
-   * Implements Drupal\Core\Database\Query\ConditionInterface::isNull().
-   */
-  public function isNull($field) {
-    $this->condition->isNull($field);
-    return $this;
-  }
-
-  /**
-   * Implements Drupal\Core\Database\Query\ConditionInterface::isNotNull().
-   */
-  public function isNotNull($field) {
-    $this->condition->isNotNull($field);
-    return $this;
-  }
-
-  /**
-   * Implements Drupal\Core\Database\Query\ConditionInterface::exists().
-   */
-  public function exists(SelectInterface $select) {
-    $this->condition->exists($select);
-    return $this;
-  }
-
-  /**
-   * Implements Drupal\Core\Database\Query\ConditionInterface::notExists().
-   */
-  public function notExists(SelectInterface $select) {
-    $this->condition->notExists($select);
-    return $this;
-  }
-
-  /**
-   * Implements Drupal\Core\Database\Query\ConditionInterface::conditions().
-   */
-  public function &conditions() {
-    return $this->condition->conditions();
-  }
-
-  /**
-   * Implements Drupal\Core\Database\Query\ConditionInterface::arguments().
-   */
-  public function arguments() {
-    return $this->condition->arguments();
-  }
-
-  /**
-   * Implements Drupal\Core\Database\Query\ConditionInterface::where().
-   */
-  public function where($snippet, $args = array()) {
-    $this->condition->where($snippet, $args);
-    return $this;
-  }
-
-  /**
-   * Implements Drupal\Core\Database\Query\ConditionInterface::compile().
-   */
-  public function compile(Connection $connection, PlaceholderInterface $queryPlaceholder) {
-    return $this->condition->compile($connection, $queryPlaceholder);
-  }
-
-  /**
-   * Implements Drupal\Core\Database\Query\ConditionInterface::compiled().
-   */
-  public function compiled() {
-    return $this->condition->compiled();
-  }
-
-  /**
    * Executes the DELETE query.
    *
    * @return
diff --git a/core/lib/Drupal/Core/Database/Query/Merge.php b/core/lib/Drupal/Core/Database/Query/Merge.php
index 34f8378..c292894 100644
--- a/core/lib/Drupal/Core/Database/Query/Merge.php
+++ b/core/lib/Drupal/Core/Database/Query/Merge.php
@@ -49,6 +49,9 @@
  * fields() and updateFields().
  */
 class Merge extends Query implements ConditionInterface {
+
+  use QueryConditionTrait;
+
   /**
    * Returned by execute() if an INSERT query has been executed.
    */
@@ -340,82 +343,6 @@ public function key($field, $value = NULL) {
   }
 
   /**
-   * Implements Drupal\Core\Database\Query\ConditionInterface::condition().
-   */
-  public function condition($field, $value = NULL, $operator = '=') {
-    $this->condition->condition($field, $value, $operator);
-    return $this;
-  }
-
-  /**
-   * Implements Drupal\Core\Database\Query\ConditionInterface::isNull().
-   */
-  public function isNull($field) {
-    $this->condition->isNull($field);
-    return $this;
-  }
-
-  /**
-   * Implements Drupal\Core\Database\Query\ConditionInterface::isNotNull().
-   */
-  public function isNotNull($field) {
-    $this->condition->isNotNull($field);
-    return $this;
-  }
-
-  /**
-   * Implements Drupal\Core\Database\Query\ConditionInterface::exists().
-   */
-  public function exists(SelectInterface $select) {
-    $this->condition->exists($select);
-    return $this;
-  }
-
-  /**
-   * Implements Drupal\Core\Database\Query\ConditionInterface::notExists().
-   */
-  public function notExists(SelectInterface $select) {
-    $this->condition->notExists($select);
-    return $this;
-  }
-
-  /**
-   * Implements Drupal\Core\Database\Query\ConditionInterface::conditions().
-   */
-  public function &conditions() {
-    return $this->condition->conditions();
-  }
-
-  /**
-   * Implements Drupal\Core\Database\Query\ConditionInterface::arguments().
-   */
-  public function arguments() {
-    return $this->condition->arguments();
-  }
-
-  /**
-   * Implements Drupal\Core\Database\Query\ConditionInterface::where().
-   */
-  public function where($snippet, $args = array()) {
-    $this->condition->where($snippet, $args);
-    return $this;
-  }
-
-  /**
-   * Implements Drupal\Core\Database\Query\ConditionInterface::compile().
-   */
-  public function compile(Connection $connection, PlaceholderInterface $queryPlaceholder) {
-    return $this->condition->compile($connection, $queryPlaceholder);
-  }
-
-  /**
-   * Implements Drupal\Core\Database\Query\ConditionInterface::compiled().
-   */
-  public function compiled() {
-    return $this->condition->compiled();
-  }
-
-  /**
    * Implements PHP magic __toString method to convert the query to a string.
    *
    * In the degenerate case, there is no string-able query as this operation
diff --git a/core/lib/Drupal/Core/Database/Query/Query.php b/core/lib/Drupal/Core/Database/Query/Query.php
index 790ed5c..8dba91b 100644
--- a/core/lib/Drupal/Core/Database/Query/Query.php
+++ b/core/lib/Drupal/Core/Database/Query/Query.php
@@ -180,25 +180,4 @@ public function &getComments() {
     return $this->comments;
   }
 
-  /**
-   * {@inheritdoc}
-   */
-  public function conditionGroupFactory($conjunction = 'AND') {
-    return new Condition($conjunction);
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function andConditionGroup() {
-    return $this->conditionGroupFactory('AND');
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function orConditionGroup() {
-    return $this->conditionGroupFactory('OR');
-  }
-
 }
diff --git a/core/lib/Drupal/Core/Database/Query/Delete.php b/core/lib/Drupal/Core/Database/Query/QueryConditionTrait.php
similarity index 54%
copy from core/lib/Drupal/Core/Database/Query/Delete.php
copy to core/lib/Drupal/Core/Database/Query/QueryConditionTrait.php
index 08e7af1..d3f2034 100644
--- a/core/lib/Drupal/Core/Database/Query/Delete.php
+++ b/core/lib/Drupal/Core/Database/Query/QueryConditionTrait.php
@@ -2,56 +2,30 @@
 
 /**
  * @file
- * Contains \Drupal\Core\Database\Query\Delete.
+ * Contains \Drupal\Core\Database\Query\QueryConditionTrait.
  */
 
 namespace Drupal\Core\Database\Query;
 
-use Drupal\Core\Database\Database;
 use Drupal\Core\Database\Connection;
 
 /**
- * General class for an abstracted DELETE operation.
+ * Provides an implementation of ConditionInterface.
  *
- * @ingroup database
+ * @see \Drupal\Core\Database\Query\ConditionInterface
  */
-class Delete extends Query implements ConditionInterface {
-
-  /**
-   * The table from which to delete.
-   *
-   * @var string
-   */
-  protected $table;
+trait QueryConditionTrait {
 
   /**
    * The condition object for this query.
    *
    * Condition handling is handled via composition.
    *
-   * @var Condition
+   * @var \Drupal\Core\Database\Query\Condition
    */
   protected $condition;
 
   /**
-   * Constructs a Delete object.
-   *
-   * @param \Drupal\Core\Database\Connection $connection
-   *   A Connection object.
-   * @param string $table
-   *   Name of the table to associate with this query.
-   * @param array $options
-   *   Array of database options.
-   */
-  public function __construct(Connection $connection, $table, array $options = array()) {
-    $options['return'] = Database::RETURN_AFFECTED;
-    parent::__construct($connection, $options);
-    $this->table = $table;
-
-    $this->condition = new Condition('AND');
-  }
-
-  /**
    * Implements Drupal\Core\Database\Query\ConditionInterface::condition().
    */
   public function condition($field, $value = NULL, $operator = '=') {
@@ -117,7 +91,7 @@ public function where($snippet, $args = array()) {
    * Implements Drupal\Core\Database\Query\ConditionInterface::compile().
    */
   public function compile(Connection $connection, PlaceholderInterface $queryPlaceholder) {
-    return $this->condition->compile($connection, $queryPlaceholder);
+    $this->condition->compile($connection, $queryPlaceholder);
   }
 
   /**
@@ -128,39 +102,24 @@ public function compiled() {
   }
 
   /**
-   * Executes the DELETE query.
-   *
-   * @return
-   *   The return value is dependent on the database connection.
+   * Implements Drupal\Core\Database\Query\ConditionInterface::conditionGroupFactory().
    */
-  public function execute() {
-    $values = array();
-    if (count($this->condition)) {
-      $this->condition->compile($this->connection, $this);
-      $values = $this->condition->arguments();
-    }
-
-    return $this->connection->query((string) $this, $values, $this->queryOptions);
+  public function conditionGroupFactory($conjunction = 'AND') {
+    return new Condition($conjunction);
   }
 
   /**
-   * Implements PHP magic __toString method to convert the query to a string.
-   *
-   * @return string
-   *   The prepared statement.
+   * Implements Drupal\Core\Database\Query\ConditionInterface::andConditionGroup().
    */
-  public function __toString() {
-    // Create a sanitized comment string to prepend to the query.
-    $comments = $this->connection->makeComment($this->comments);
-
-    $query = $comments . 'DELETE FROM {' . $this->connection->escapeTable($this->table) . '} ';
-
-    if (count($this->condition)) {
-
-      $this->condition->compile($this->connection, $this);
-      $query .= "\nWHERE " . $this->condition;
-    }
+  public function andConditionGroup() {
+    return $this->conditionGroupFactory('AND');
+  }
 
-    return $query;
+  /**
+   * Implements Drupal\Core\Database\Query\ConditionInterface::orConditionGroup().
+   */
+  public function orConditionGroup() {
+    return $this->conditionGroupFactory('OR');
   }
+
 }
diff --git a/core/lib/Drupal/Core/Database/Query/Select.php b/core/lib/Drupal/Core/Database/Query/Select.php
index 8ccf16a..3be5a2f 100644
--- a/core/lib/Drupal/Core/Database/Query/Select.php
+++ b/core/lib/Drupal/Core/Database/Query/Select.php
@@ -18,6 +18,8 @@
  */
 class Select extends Query implements SelectInterface {
 
+  use QueryConditionTrait;
+
   /**
    * The fields to SELECT.
    *
@@ -72,13 +74,6 @@ class Select extends Query implements SelectInterface {
   protected $group = array();
 
   /**
-   * The conditional object for the WHERE clause.
-   *
-   * @var \Drupal\Core\Database\Query\Condition
-   */
-  protected $where;
-
-  /**
    * The conditional object for the HAVING clause.
    *
    * @var \Drupal\Core\Database\Query\Condition
@@ -139,7 +134,7 @@ public function __construct($table, $alias = NULL, Connection $connection, $opti
     $options['return'] = Database::RETURN_STATEMENT;
     parent::__construct($connection, $options);
     $conjunction = isset($options['conjunction']) ? $options['conjunction'] : 'AND';
-    $this->where = new Condition($conjunction);
+    $this->condition = new Condition($conjunction);
     $this->having = new Condition($conjunction);
     $this->addJoin(NULL, $table, $alias);
   }
@@ -191,27 +186,12 @@ public function getMetaData($key) {
   /**
    * {@inheritdoc}
    */
-  public function condition($field, $value = NULL, $operator = '=') {
-    $this->where->condition($field, $value, $operator);
-    return $this;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function &conditions() {
-    return $this->where->conditions();
-  }
-
-  /**
-   * {@inheritdoc}
-   */
   public function arguments() {
     if (!$this->compiled()) {
       return NULL;
     }
 
-    $args = $this->where->arguments() + $this->having->arguments();
+    $args = $this->condition->arguments() + $this->having->arguments();
 
     foreach ($this->tables as $table) {
       if ($table['arguments']) {
@@ -241,48 +221,8 @@ public function arguments() {
   /**
    * {@inheritdoc}
    */
-  public function where($snippet, $args = array()) {
-    $this->where->where($snippet, $args);
-    return $this;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function isNull($field) {
-    $this->where->isNull($field);
-    return $this;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function isNotNull($field) {
-    $this->where->isNotNull($field);
-    return $this;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function exists(SelectInterface $select) {
-    $this->where->exists($select);
-    return $this;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function notExists(SelectInterface $select) {
-    $this->where->notExists($select);
-    return $this;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
   public function compile(Connection $connection, PlaceholderInterface $queryPlaceholder) {
-    $this->where->compile($connection, $queryPlaceholder);
+    $this->condition->compile($connection, $queryPlaceholder);
     $this->having->compile($connection, $queryPlaceholder);
 
     foreach ($this->tables as $table) {
@@ -302,7 +242,7 @@ public function compile(Connection $connection, PlaceholderInterface $queryPlace
    * {@inheritdoc}
    */
   public function compiled() {
-    if (!$this->where->compiled() || !$this->having->compiled()) {
+    if (!$this->condition->compiled() || !$this->having->compiled()) {
       return FALSE;
     }
 
@@ -892,9 +832,9 @@ public function __toString() {
     }
 
     // WHERE
-    if (count($this->where)) {
+    if (count($this->condition)) {
       // There is an implicit string cast on $this->condition.
-      $query .= "\nWHERE " . $this->where;
+      $query .= "\nWHERE " . $this->condition;
     }
 
     // GROUP BY
@@ -950,7 +890,7 @@ public function __clone() {
     // want to clone the database connection object as that would duplicate the
     // connection itself.
 
-    $this->where = clone($this->where);
+    $this->condition = clone($this->condition);
     $this->having = clone($this->having);
     foreach ($this->union as $key => $aggregate) {
       $this->union[$key]['query'] = clone($aggregate['query']);
diff --git a/core/lib/Drupal/Core/Database/Query/Update.php b/core/lib/Drupal/Core/Database/Query/Update.php
index 5c652e7..3f7fc39 100644
--- a/core/lib/Drupal/Core/Database/Query/Update.php
+++ b/core/lib/Drupal/Core/Database/Query/Update.php
@@ -17,6 +17,8 @@
  */
 class Update extends Query implements ConditionInterface {
 
+  use QueryConditionTrait;
+
   /**
    * The table to update.
    *
@@ -39,15 +41,6 @@ class Update extends Query implements ConditionInterface {
   protected $arguments = array();
 
   /**
-   * The condition object for this query.
-   *
-   * Condition handling is handled via composition.
-   *
-   * @var \Drupal\Core\Database\Query\Condition
-   */
-  protected $condition;
-
-  /**
    * Array of fields to update to an expression in case of a duplicate record.
    *
    * This variable is a nested array in the following format:
@@ -81,82 +74,6 @@ public function __construct(Connection $connection, $table, array $options = arr
   }
 
   /**
-   * Implements Drupal\Core\Database\Query\ConditionInterface::condition().
-   */
-  public function condition($field, $value = NULL, $operator = '=') {
-    $this->condition->condition($field, $value, $operator);
-    return $this;
-  }
-
-  /**
-   * Implements Drupal\Core\Database\Query\ConditionInterface::isNull().
-   */
-  public function isNull($field) {
-    $this->condition->isNull($field);
-    return $this;
-  }
-
-  /**
-   * Implements Drupal\Core\Database\Query\ConditionInterface::isNotNull().
-   */
-  public function isNotNull($field) {
-    $this->condition->isNotNull($field);
-    return $this;
-  }
-
-  /**
-   * Implements Drupal\Core\Database\Query\ConditionInterface::exists().
-   */
-  public function exists(SelectInterface $select) {
-    $this->condition->exists($select);
-    return $this;
-  }
-
-  /**
-   * Implements Drupal\Core\Database\Query\ConditionInterface::notExists().
-   */
-  public function notExists(SelectInterface $select) {
-    $this->condition->notExists($select);
-    return $this;
-  }
-
-  /**
-   * Implements Drupal\Core\Database\Query\ConditionInterface::conditions().
-   */
-  public function &conditions() {
-    return $this->condition->conditions();
-  }
-
-  /**
-   * Implements Drupal\Core\Database\Query\ConditionInterface::arguments().
-   */
-  public function arguments() {
-    return $this->condition->arguments();
-  }
-
-  /**
-   * Implements Drupal\Core\Database\Query\ConditionInterface::where().
-   */
-  public function where($snippet, $args = array()) {
-    $this->condition->where($snippet, $args);
-    return $this;
-  }
-
-  /**
-   * Implements Drupal\Core\Database\Query\ConditionInterface::compile().
-   */
-  public function compile(Connection $connection, PlaceholderInterface $queryPlaceholder) {
-    return $this->condition->compile($connection, $queryPlaceholder);
-  }
-
-  /**
-   * Implements Drupal\Core\Database\Query\ConditionInterface::compiled().
-   */
-  public function compiled() {
-    return $this->condition->compiled();
-  }
-
-  /**
    * Adds a set of field->value pairs to be updated.
    *
    * @param $fields