Indexes: Indexing Attachments

The AttachmentsFor method returns a list of attachments in a given document as well as basic information like Name or Size about each of them.

• AttachmentsFor
• AttachmentName

IEnumerable<AttachmentName> AttachmentsFor(object doc);

public string Name;

public string Hash;

public string ContentType;

public long Size;

Creating an index using AttachmentsFor()

The AttachmentsFor method is available in AbstractIndexCreationTask.

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      public class Employees_ByAttachmentDetails : 
          AbstractIndexCreationTask<Employee, Employees_ByAttachmentDetails.IndexEntry>
      {
          public class IndexEntry
          {
              public string EmployeeName { get; set; }
              
              public string[] AttachmentNames { get; set; }
              public string[] AttachmentContentTypes { get; set; }
              public long[] AttachmentSizes { get; set; }
          }

          public Employees_ByAttachmentDetails()
          {
              Map = employees => from employee in employees
                  
                  // Call 'AttachmentsFor' to get attachments details
                  let attachments = AttachmentsFor(employee)
                  
                  select new IndexEntry()
                  {
                      // Can index info from document properties:
                      EmployeeName = employee.FirstName + " " + employee.LastName,
                      
                      // Index DETAILS of attachments:
                      AttachmentNames = attachments.Select(x => x.Name).ToArray(),
                      AttachmentContentTypes = attachments.Select(x => x.ContentType).ToArray(),
                      AttachmentSizes = attachments.Select(x => x.Size).ToArray()
                  };
          }
      }

Querying the index

• Sync
• Async
• DocumentQuery

//return all employees that have an attachment called "cv.pdf"
List<Employee> employees = session
  .Query<Employees_ByAttachmentNames.Result, Employees_ByAttachmentNames>()
  .Where(x => x.AttachmentNames.Contains("cv.pdf"))
  .OfType<Employee>()
  .ToList();

//return all employees that have an attachment called "cv.pdf"
List<Employee> employees = await asyncSession
  .Query<Employees_ByAttachmentNames.Result, Employees_ByAttachmentNames>()
  .Where(x => x.AttachmentNames.Contains("cv.pdf"))
  .OfType<Employee>()
  .ToListAsync();

//return all employees that have an attachment called "cv.pdf"
List<Employee> employees = session
  .Advanced
  .DocumentQuery<Employee, Employees_ByAttachmentNames>()
  .ContainsAny("AttachmentNames", new[] { "cv.pdf" })
  .ToList();