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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 subscription with include statement
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.
name = await store.Subscriptions.CreateAsync(new SubscriptionCreationOptions<Order>
{
Name = "OrdersProcessingSumbscription"
});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.
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.
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.
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 = load(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 subscription with include statement
Here we create a subscription on Orders collection, which returns the orders and brings along all products mentioned in the order as included documents. See the usage example here.
Include statements supported only with raw RQL. Include statements come in two forms, like in any other RQL statements:
1. Include statement in the end of the query, starting with the include keyword, followed by paths to the field containing the ids of the documents to include.
If projection is performed, the mechanism will look for the paths in the projected result, rather then the original document.
It is recommended to prefer this approach when possible both because of clarity of the query and slightly better performance.
2. Include function call inside a 'declared' function.
store.Subscriptions.Create(new SubscriptionCreationOptions()
{
Query = @"from Orders include Lines[].Product"
});store.Subscriptions.Create(new SubscriptionCreationOptions()
{
Query = @"
declare function includeProducts(doc)
{
doc.IncludedFields=0;
doc.LinesCount = doc.Lines.length;
for (let i=0; i< doc.Lines.length; i++)
{
doc.IncludedFields++;
include(doc.Lines[i].Product);
}
return doc;
}
from Orders as o select includeProducts(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.
name = store.Subscriptions.Create(
new SubscriptionCreationOptions<Revision<Order>>());name = await store.Subscriptions.CreateAsync(new SubscriptionCreationOptions()
{
Query = @"From Orders (Revisions = true)"
});
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