title: Createmany in Strongloop Loopback
body: <p>I have an Order model which hasMany OrderItem models. But once a client wants to create an Order, it has to create an Order object first then for each product he added to his basket, he needs to create responding OrderItems separately. As you may notice it causes many reduntant requests. May be I can make a custom method for OrderItems which consumes a product list. But i was wondering if there is a built in mechanism for this like createMany since it is a very useful operation.</p>
  
  <p>ORDER MODEL</p>
  
  <pre><code> {
    "name": "Order",
    "plural": "Orders",
    "base": "PersistedModel",
    "idInjection": true,
    "properties": {
      "customerId": {
        "type": "number",
        "required": true
      },
      "branchId": {
        "type": "number",
        "required": true
      }
    },
    "validations": [],
    "relations": {
      "orderItems": {
        "type": "hasMany",
        "model": "OrderItem",
        "foreignKey": "orderId"
      }
    },
    "acls": [],
    "methods": []
  }
  </code></pre>
  
  <p>ORDERITEM MODEL</p>
  
  <pre><code>{
    "name": "OrderItem",
    "plural": "OrderItems",
    "base": "PersistedModel",
    "idInjection": true,
    "properties": {
      "UnitPrice": {
        "type": "number"
      },
      "productId": {
        "type": "number",
        "required": true
      },
      "purchaseOrderId": {
        "type": "number",
        "required": true
      },
      "quantity": {
        "type": "number"
      }
    },
    "validations": [],
    "relations": {
      "product": {
        "type": "belongsTo",
        "model": "Product",
        "foreignKey": "productId"
      },
      "purchaseOrder": {
        "type": "belongsTo",
        "model": "PurchaseOrder",
        "foreignKey": ""
      }
  
    },
    "acls": [],
    "methods": []
  }
  </code></pre>