Data Subscriptions: Common Data Subscription Creation Examples

In this page:

Create subscription on all documents in a collection
Create subscription with filtering
Create subscription with filtering and projection
Create subscription with load document in filter projection
Create revisions enabled subscription

Create subscription on all documents in a collection

Here we create a plain subscription on the Orders collection, without any constraint or transformation.

• Generic-syntax
• RQL-syntax

name = await store.Subscriptions.CreateAsync(new SubscriptionCreationOptions<Order>
{
  Name = "OrdersProcessingSubscription"                
});

name = await store.Subscriptions.CreateAsync(new SubscriptionCreationOptions()
{
  Query = "From Orders"
});

Create subscription with filtering

Here we create a subscription on Orders collection, which total order revenue is greater than 100.

• Generic-syntax
• RQL-syntax

name = await store.Subscriptions.CreateAsync<Order>(x =>
  x.Lines.Sum(line => line.PricePerUnit * line.Quantity) > 100);

name = await store.Subscriptions.CreateAsync(new SubscriptionCreationOptions()
{
  Query = @"
              declare function getOrderLinesSum(doc){
                  var sum = 0;
                  for (var i in doc.Lines) { sum += doc.Lines[i];}
                  return sum;
              }
              From Orders as o 
              Where getOrderLinesSum(o) > 100"
});

Create subscription with filtering and projection

Here we create a subscription on Orders collection, which total order revenue is greater than 100, and return only ID and total revenue.

• Generic-syntax
• RQL-syntax

name = store.Subscriptions.Create(
  new SubscriptionCreationOptions<Order>()
  {
      Filter = x => x.Lines.Sum(line => line.PricePerUnit * line.Quantity) > 100,
      Projection = x => new
      {
          Id = x.Id,
          Total = x.Lines.Sum(line => line.PricePerUnit * line.Quantity)
      }
  });

name = await store.Subscriptions.CreateAsync(new SubscriptionCreationOptions()
{
  Query = @"declare function getOrderLinesSum(doc){
                  var sum = 0;
                  for (var i in doc.Lines) { sum += doc.Lines[i];}
                  return sum;
              }

              declare function projectOrder(doc){
                  return {
                      Id: order.Id,
                      Total: getOrderLinesSum(order)
                  };
              }

              From Orders as o 
              Where getOrderLinesSum(o) > 100
              Select projectOrder(o)"
});

Create subscription with load document in filter projection

Here we create a subscription on Orders collection, which total order revenue is greater than 100, and return ID, total revenue, shipping address and responsible employee name.

• Generic-syntax
• RQL-syntax

name = store.Subscriptions.Create(
  new SubscriptionCreationOptions<Order>()
  {
      Filter = x => x.Lines.Sum(line => line.PricePerUnit * line.Quantity) > 100,
      Projection = x => new
      {
          Id = x.Id,
          Total = x.Lines.Sum(line => line.PricePerUnit * line.Quantity),
          ShipTo = x.ShipTo,
          EmployeeName = RavenQuery.Load<Employee>(x.Employee).FirstName + " " +
                         RavenQuery.Load<Employee>(x.Employee).LastName
      }
  });

name = await store.Subscriptions.CreateAsync(new SubscriptionCreationOptions()
{
  Query = @"declare function getOrderLinesSum(doc){
                  var sum = 0;
                  for (var i in doc.Lines) { sum += doc.Lines[i];}
                  return sum;
              }

              declare function projectOrder(doc){
                  var employee = LoadDocument(doc.Employee);
                  return {
                      Id: order.Id,
                      Total: getOrderLinesSum(order),
                      ShipTo: order.ShipTo,
                      EmployeeName: employee.FirstName + ' ' + employee.LastName

                  };
              }

              From Orders as o 
              Where getOrderLinesSum(o) > 100
              Select projectOrder(o)"
});

Create revisions enabled subscription

Here we create a subscription on Orders collection, which returns current and previous version of the subscriptions. Please see the page dedicated to subscriptions with revisions for more details and examples.

• Generic-syntax
• RQL-syntax

name = store.Subscriptions.Create(
  new SubscriptionCreationOptions<Revision<Order>>());

name = await store.Subscriptions.CreateAsync(new SubscriptionCreationOptions()
{
  Query = @"From Orders (Revisions = true)"
});