Create or Modify Counters

Flow:

• Open a session.
• Create an instance of CountersFor.
  • Either pass CountersFor an explicit document ID, -or-
  • Pass it an entity tracked by the session, e.g. a document object returned from session.Query or from session.Load.
• Call CountersFor.Increment.
• Call session.SaveChanges for the changes to take effect.

Note:

• Modifying a Counter using Increment only takes effect when session.SaveChanges() is executed.
• To decrease a Counter's value, pass the method a negative number to the Increment method.

// Open a session
using (var session = docStore.OpenSession())
{
    // Pass CountersFor's constructor a document ID  
    var documentCounters = session.CountersFor("products/1-A");

    // Use `CountersFor.Increment`:
    // ============================
    
    // Increase "ProductLikes" by 1, or create it if doesn't exist with a value of 1
    documentCounters.Increment("ProductLikes"); 
    
    // Increase "ProductPageViews" by 15, or create it if doesn't exist with a value of 15
    documentCounters.Increment("ProductPageViews", 15);
    
    // Decrease "DaysLeftForSale" by 10, or create it if doesn't exist with a value of -10
    documentCounters.Increment("DaysLeftForSale", -10);

    // Execute all changes by calling SaveChanges
    session.SaveChanges();
}

void Increment(string counterName, long delta = 1);