Firebase“值”返回重复值

Question

我正在使用Firebase实时数据库和jquery进行项目。我必须从两个不同的节点检索数据并将其存储在数据表中。第一个查询返回值，并基于该值，我必须从另一个节点检索值。现在的问题是它返回的值很好，但是返回重复的值。

这是我的代码：

var database = firebase.database();
var userRef = database.ref("Users");
var orderRef = database.ref("Orders");
userRef.on("value", function(snapshot) {
    snapshot.forEach(function(childSnapshot) {
        userType = childSnapshot.val().UserType;

        if (userType === 'r') {
           restId = childSnapshot.key;
           displayName = childSnapshot.val().DisplayName;
           location = childSnapshot.val().Location;

           orderRef.on("value", function(oSnapshot) {
               oSnapshot.forEach(function(oChildSnapshot) {
                   location2 = oChildSnapshot.val().pickupLocation;

                   if (location === location2) {

                      deliveryLocation = oChildSnapshot.val().deliveryLocation;
                      driver = oChildSnapshot.val().driver;
                      status = oChildSnapshot.val().status;
                      completionTime = oChildSnapshot.val().timeOfCompletion;
                      pickupTime = oChildSnapshot.val().timeOfPickup;
                      date = oChildSnapshot.val().date;

                      table.row.add([restId, displayName, deliveryLocation, driver, status, completionTime, pickupTime, date]).node().id = "restId";
                       table.draw(false);
                   }
              });
            });
          }
        });
   });

这是输出：