I have the following c# function that selects all the documents out of a couchbase bucket.
public IEnumerable<CatalogueItem> GetAll()
{
using (var bucket = _cluster.OpenBucket(_bucketName))
{
var request = new QueryRequest("SELECT `boxcatalogue`.* FROM `boxcatalogue` LIMIT 100;").UseStreaming(true);
var query = bucket.Query<CatalogueItem>(request);
return query.Rows;
}
}
I can run the same query from the Couchbase console and it returns my documents correctly. But when calling from C# code query.Rows is null. When inspecting the query object in a breakpoint I can see it has a private member called Results which is populated with the results of the query, so why is Rows null?
Related
So I am kind of new to Web services, and I am trying to wrap my head around how it works.
Basically, I need to receive an ID from one side, pass it to another source which returns the employee information.
Now, this is what I did so far:
[WebMethod(Description = "Returns employee object for id")]
public Employee GetEmployeeById(int Id)
{
// how to ?
return new Employee( // data from outer source);
}
I see the wsdl, where you can send the id to the function.
How does the other source get the information from my service?
The another source means that anywhere you want to connect to. Maybe it's a database, other web service, or only a text file....
For example, you have a db that saves employee data. You can use Entity Framework to get employee data from db.
Like this:
[WebMethod(Description = "Returns employee object for id")]
public Employee GetEmployeeById(int Id)
{
using(var context = new MyDbContext())
{
var emp = context.Employees.Where(x => x.Id == Id).FirstOrDefault();
return emp;
}
}
I replicated the architecture below.
I insert the gps positions (document db) in cosmos db and in the javascript client (maps google) the pin moves.
All the step works: insert document db, trigger azure function and signalr that link client and document db in azure cosmos db.
The code to upload a document db in Cosmos:
Microsoft.Azure.Documents.Document doc = client.CreateDocumentAsync(UriFactory.CreateDocumentCollectionUri(databaseName, collectionName), estimatedPathDocument).Result.Resource;
ret[0] = doc.Id;
Azure function:
public static async Task Run(IReadOnlyList<Document> input, IAsyncCollector<SignalRMessage> signalRMessages, ILogger log)
{
if (input != null && input.Count > 0)
{
var val = input.Select((d) => new
{
genKey = d.GetPropertyValue<string>("genKey"),
dataType = d.GetPropertyValue<string>("dataType")
});
await signalRMessages.AddAsync(new SignalRMessage
{
UserId = val.First().genKey,
Target = "tripUpdated",
Arguments = new[] { input }
});
}
}
When I insert only one position the function in azure records the event and fire by moving the pin.
The problem is when I insert sequentially a series of positions in an almost instantaneous way and this does not trigger the function for the document following the first one.
Only if i insert a delay only some documents fire the trigger:
Microsoft.Azure.Documents.Document doc = client.CreateDocumentAsync(UriFactory.CreateDocumentCollectionUri(databaseName, collectionName), estimatedPathDocument).Result.Resource;
Thread.Sleep(3000);
ret[0] = doc.Id;
I don't know if I load the documents correctly, but even managing them in an asynchronous way (see under), it almost seems like the trigger is triggered only when the document in cosmos db is "really / physically" created.
Task.Run(async () => await AzureCosmosDB_class.MyDocumentAzureCosmosDB.CreateRealCoordDocumentIfNotExists_v1("axylog-cdb-01", "axylog-collection-01", realCoord, uri, key));
The solution can be to list the documents in a queue and load them on azure cosmos sequentially after a delay of about ten seconds one from the other?
I'm starting with REDIS and the StackExchange Redis client. I'm wondering if I'm getting the best performance for getting multiple items at once from REDIS.
Situation:
I have an ASP.NET MVC web application that shows a personal calendar on the dashboard of the user. Because the dashboard is the landing page it's heavily used.
To show the calendar items, I first get all calendar item ID's for that particular month:
RedisManager.RedisDb.StringGet("calendaritems_2016_8");
// this returns JSON Serialized List<int>
Then, for each calendar item id I build a list of corresponding cache keys:
"CalendarItemCache_1"
"CalendarItemCache_2"
"CalendarItemCache_3"
etc.
With this collection I reach out to REDIS with a generic function:
var multipleItems = CacheHelper.GetMultiple<CalendarItemCache>(cacheKeys);
That's implemented like:
public List<T> GetMultiple<T>(List<string> keys) where T : class
{
var taskList = new List<Task>();
var returnList = new ConcurrentBag<T>();
foreach (var key in keys)
{
Task<T> stringGetAsync = RedisManager.RedisDb.StringGetAsync(key)
.ContinueWith(task =>
{
if (!string.IsNullOrWhiteSpace(task.Result))
{
var deserializeFromJson = CurrentSerializer.Serializer.DeserializeFromJson<T>(task.Result);
returnList.Add(deserializeFromJson);
return deserializeFromJson;
}
else
{
return null;
}
});
taskList.Add(stringGetAsync);
}
Task[] tasks = taskList.ToArray();
Task.WaitAll(tasks);
return returnList.ToList();
}
Am I implementing pipelining correct? The REDIS CLI monitor shows:
1472728336.718370 [0 127.0.0.1:50335] "GET" "CalendarItemCache_1"
1472728336.718389 [0 127.0.0.1:50335] "GET" "CalendarItemCache_2"
etc.
I'm expecting some kind of MGET command.
Many thanks in advance.
I noticed an overload method for StringGet that accepts a RedisKey[]. Using this, I see a MGET command in the monitor.
public List<T> GetMultiple<T>(List<string> keys) where T : class
{
List<RedisKey> list = new List<RedisKey>(keys.Count);
foreach (var key in keys)
{
list.Add(key);
}
RedisValue[] result = RedisManager.RedisDb.StringGet(list.ToArray());
var redisValues = result.Where(x=>x.HasValue);
var multiple = redisValues.Select(x => DeserializeFromJson<T>(x)).ToList();
return multiple;
}
I am trying to insert a sub class (document) of "Video" into my Organization document.
However, when I try to add a record, I get "Object reference is not set to an instance of an object."
I tried to use Add and Insert, but neither worked. I looked at the Dcoument explorer and I can see that Videos is returning "null."
I am assuming my problem is that Document DB doesn't know that Video is a list. (in my model, I have defined it as a list though)
Also, I have tried created new objects for Organization and Video. Also, I have a class called Category, it has the exact same code (except the object is Category) and it is inserting fine.
Below is the action that I am using.
[HttpPost]
[ValidateAntiForgeryToken]
public async Task<ActionResult> Create([Bind(Include = "name,description,link")] Video video)
{
if (ModelState.IsValid)
{
UserSession usersession = new UserSession();
usersession = (UserSession)Session["user"];
Organization organization = (Organization)DocumentDBRepository<Organization>.GetItem(d => d.Id == usersession.organizationId);
video.DateAdded = DateTime.Now;
organization.Videos.Add(video);
await DocumentDBRepository<Organization>.UpdateItemAsync(organization.Id, organization);
return RedirectToAction("Index");
}
return View(video);
}
Set organization.Videos to a non-null value. Document db simply preserves what you stored. Apparently, you previously stored null.
i am working on an asp.net mvc web application. and i have the following repository method,, where i will be passing the .Include() dynamically :-
public async Task<SecurityRole> FindSecurityRole(int id,string path="")
{
return await context.SecurityRoles.Include(path).SingleOrDefaultAsync(a2 => a2.SecurityRoleID == id);
}
now inside my controller i want to call the above method as follow:-
await uniteofwork.SecurityRoleRepository.FindSecurityRole(id.Value,)
but i am not sure what are the apporachies i can follow to pass the properties ?
Thanks
You can chain calls to things like Include over multiple lines by storing the result in a variable. Nothing will actually hit your database until you call an evaluating expression like SingleOrDefaultAsync here.
var query = context.SecurityRoles;
foreach (var include in path.Split(',', StringSplitOptions.RemoveEmptyEntries))
{
query = query.Include(include);
}
return await query.SingleOrDefaultAsync(a2 => a2.SecurityRoleID == id);
Splitting the string allows you to pass multiple include hierarchies at once, comma-delimited.