如何在json商店中加入兩個集合？

Question

我正在使用IBM Worklight。我需要訪問兩個集合中的數據。是否有任何解決方案來加入2個集合並獲得必填字段？

Answer 1

JSONSTORE無法合併集合。

但是後續的博客文章的細節來實現一個方法：https://mobilefirstplatform.ibmcloud.com/blog/2015/02/24/working-jsonstore-collections-join/

1. 創建集合：

   var data = [ 
            {order_id : 462, order_date : '1-1-2000'}, 
            {order_id: 608, order_date : '2-2-2001'}, 
            {order_id: 898, order_date : '3-3-2002'} 
            ]; 
         var counter = 0; 
         var q = async.queue(function (task, callback) { 
          setTimeout(function() { 
           WL.JSONStore.get('orders').add(task.data, {additionalSearchFields: {customer_id: task.customer_id}}); 
           callback(++counter); 
          },0); 
         },1); 
         for(var i = 0; i < data.length; i++){ 
         q.push({data : data[i], customer_id: i+1}, function(counter){ 
          console.log("Added Order Doc " + counter); 
         }); 
         } 
        q.drain = function(){ 
         setTimeout(function() { 
          console.log("Finished adding order documents"); 
          WL.JSONStore.get("orders").findAll({filter : ["customer_id", "order_id", "order_date"]}) 
           .then(function (res) { 
            ordersCollectionData = res; 
            document.getElementById("orders").innerHTML = JSON.stringify(res, null, "\t"); 
           }) 
           .fail(function (err) { 
             console.log("There was a problem at " + JSON.stringify(err)); 
           }); 
         },0); 
        }; 
   

2. ：

   var OrdersCollection = { 
        orders: { 
        searchFields: { 
         order_id: 'integer', 
         order_date: 'string' 
        }, 
        additionalSearchFields: { 
         customer_id: 'integer' 
        } 
        } 
   }; 
   var CustomerCollection = { 
        customers: { 
         searchFields: { 
          customer_name : 'string', 
          contact_name : 'string', 
          country : 'string' 
         }, 
         additionalSearchFields : { 
          customer_id : 'integer' 
         } 
        } 
       }; 
   

3. 使用其他搜索字段添加數據

   查找要合併的文檔：

   WL.JSONStore.get('orders').findAll({filter : ['customer_id', 'order_id', 'order_date']}) 
           .then(function (res) { 
            ordersCollectionData = res; 
           }); 
   

4. 合併

   var shared_index = 'customer_id'; 
   var mergedCollection = []; 
   mergedCollection =_.merge(customerCollectionData, ordersCollectionData, function(a, b){ 
        if(_.isObject(a) && (a[shared_index] == b[shared_index])) { 
         return _.merge({}, a, b); 
        } 
   });