[5.2] Allows developers to traverse their query result via a cursor

src/Illuminate/Database/Connection.php

@@ -342,6 +342,34 @@ public function select($query, $bindings = [], $useReadPdo = true)
         });
     }
 
+    /**
+     * Run a select statement against the database and returns a cursor.
+     *
+     * @param  string  $query
+     * @param  array  $bindings
+     * @param  bool  $useReadPdo
+     * @return mixed
+     */
+    public function cursor($query, $bindings = [], $useReadPdo = true)
+    {
+        return $this->run($query, $bindings, function ($me, $query, $bindings) use ($useReadPdo) {
+            if ($me->pretending()) {
+                return [];
+            }
+
+            // For select statements, we'll simply execute the query and return an array
+            // of the database result set. Each element in the array will be a single
+            // row from the database table, and will either be an array or objects.
+            $statement = $this->getPdoForSelect($useReadPdo)->prepare($query);
+
+            $statement->setFetchMode($me->getFetchMode());
+
+            $statement->execute($me->prepareBindings($bindings));
+
+            return $statement;
+        });
+    }
+
     /**
      * Get the PDO connection to use for a select query.
      *

src/Illuminate/Database/Eloquent/Builder.php

@@ -290,6 +290,33 @@ public function firstOrFail($columns = ['*'])
         throw (new ModelNotFoundException)->setModel(get_class($this->model));
     }
 
+    /**
+     * Traverses through a result set using a cursor.
+     *
+     * @return void
+     */
+    public function cursor()
+    {
+        $builder = $this->applyScopes();
+
+        $statement = $builder->query->cursor();
+
+        while ($row = $statement->fetch()) {
+            // On each result set, we will pass them to the callback and then let the
+            // developer take care of everything within the callback, which allows us to
+            // keep the memory low for spinning through large result sets for working.
+
+            if ($row === false) {
+                return;
+            }
+
+            //Hydrate and yield an Eloquent Model
+            $model = $this->model->newFromBuilder($row);
+
+            yield $model;
+        }
+    }
+
     /**
      * Execute the query as a "select" statement.
      *

src/Illuminate/Database/Query/Builder.php

@@ -1631,6 +1631,18 @@ protected function restoreFieldsForCount()
         $this->bindingBackups = [];
     }
 
+    /**
+     * Execute the query as a "select" statement.
+     *
+     * @return mixed
+     */
+    public function cursor()
+    {
+        $results = $this->connection->cursor($this->toSql(), $this->getBindings(), ! $this->useWritePdo);
+
+        return $results;
+    }
+
     /**
      * Chunk the results of the query.
      *