EDIT:
Not looking for the javascript way of doing this. I am looking for the MongoDB C# 2.0 driver way of doing this (I know it might not be possible; but I hope somebody knows a solution).
I am trying to update the value of an item embedded in an array on the primary document in my mongodb.
I am looking for a strongly typed way to do this. I am using the Mongodb c# 2.0 driver
I can do it by popping the element, updating the value, then reinserting. This just doesn't feel right; since I am overwriting what might have been written in the meantime.
Here is what I have tried so far but with no luck:
private readonly IMongoCollection<TempAgenda> _collection;
void Main()
{
var collectionName = "Agenda";
var client = new MongoClient("mongodb://localhost:27017");
var db = client.GetDatabase("Test");
_collection = db.GetCollection<TempAgenda>(collectionName);
UpdateItemTitle(1, 1, "hello");
}
public void UpdateItemTitle(string agendaId, string itemId, string title){
var filter = Builders<TempAgenda>.Filter.Eq(x => x.AgendaId, agendaId);
var update = Builders<TempAgenda>.Update.Set(x => x.Items.Single(p => p.Id.Equals(itemId)).Title, title);
var result = _collection.UpdateOneAsync(filter, update).Result;
}
Took me a while to figure this out as it doesn't appear to be mentioned in any of the official documentation (or anywhere else). I did however find this on their issue tracker, which explains how to use the positional operator $ with the C# 2.0 driver.
This should do what you want:
public void UpdateItemTitle(string agendaId, string itemId, string title){
var filter = Builders<TempAgenda>.Filter.Where(x => x.AgendaId == agendaId && x.Items.Any(i => i.Id == itemId));
var update = Builders<TempAgenda>.Update.Set(x => x.Items[-1].Title, title);
var result = _collection.UpdateOneAsync(filter, update).Result;
}
Notice that your Item.Single() clause has been changed to Item.Any() and moved to the filter definition.
[-1] or .ElementAt(-1) is apparently treated specially (actually everything < 0) and will be replaced with the positional operator $.
The above will be translated to this query:
db.Agenda.update({ AgendaId: 1, Items.Id: 1 }, { $set: { Items.$.Title: "hello" } })
Thanks, this was helpful. I have an addition though, I've used the above for arrays, pushing to a nested array and pulling from one. The issue I have found is that if I had an int array (So not an object, just a simple int array) that the PullFilter didn't actually work - "Unable to determine the serialization information" which is strange as it's only an array of ints. What I ended up doing was making it an array of objects with only one int parameter, and it all started to work. Possibly a bug, or perhaps my lack of understanding. Anyway, as I've struggled to find information about pulling and pushing to nested object arrays with the C# 2.0 driver, I thought I should post my findings here, as they use the above syntax.
var filter = Builders<MessageDto>.Filter.Where(x => x._id == entity.ParentID && x.NestedArray.Any(i => i._id == entity._id));
var update = Builders<MessageDto>.Update.PullFilter(x => x.NestedArray.ElementAt(-1).User, Builders<User>.Filter.Eq(f => f.UserID, userID));
Collection<MessageDto>(currentUser).UpdateOneAsync(filter, update);
And also:
var filter = Builders<MessageDto>.Filter.Where(x => x._id == entity.ParentID && x.NestedArray.Any(i => i._id == entity._id));
var update = Builders<MessageDto>.Update.Push(x => x.NestedArray.ElementAt(-1).Users, new User { UserID = userID });
Collection<MessageDto>(currentUser).UpdateOneAsync(filter, update);
The correct way to update a Document or sub array is as follows:
var filter = Builders<Declaracion>.Filter.Where(x => x.Id == di && x.RemuneracionMensualActual.RemuneracionActIndustrial.Any(s => s.Id == oid));
var update = Builders<Declaracion>.Update.Set(x => x.RemuneracionMensualActual.RemuneracionActIndustrial.ElementAt(-1).Ingreso, datos.ActividadIndustrial.Ingreso)
.Set(x => x.RemuneracionMensualActual.RemuneracionActIndustrial.ElementAt(-1).RazonSocial, datos.ActividadIndustrial.RazonSocial)
.Set(x => x.RemuneracionMensualActual.RemuneracionActIndustrial.ElementAt(-1).TipoNegocio, datos.ActividadIndustrial.TipoNegocio);
Related
I've been trying to Sort a collection using MongoDB SortDefinition but whenever I "sort" the collection via a single sort definition, all I get returned is an empty list. However, when I use more than one sort definitions, it returns values.
var TestSort1 = Builders<Scenario>.Sort.Ascending("Name");
var filtered1 = await _context
.DbCollection
.Find(_ => true)
.Sort(TestSort1)
.ToListAsync();
The code above returns an empty list. However, the code below works fine.
var TestSort2 = Builders<Scenario>.Sort.Ascending("Name").Ascending("Owner");
var filtered2 = await _context
.DbCollection
.Find(_ => true)
.Sort(TestSort2)
.ToListAsync();
Is it possible to use a single SortDefinition to sort the collection? Or maybe I am using the SortDefinition wrong?
Maybe you should try using the fluent C# syntax for creating aggregation pipelines...
var collection = database.GetCollection<FiltroCond>("dbCENTRAL");
var filter = Builders<FiltroCond>.Filter.Eq(x => x.PartnerId, cliente)
& Builders<FiltroCond>.Filter.Eq(x => x.TP_PESSOA, 3)
& Builders<FiltroCond>.Filter.Gte(x => x.FG_ATIVO, true);
var result = collection.Aggregate().Match(filter)
.Project(p => new FiltroCond { CD_CLIENTE = p.CD_CLIENTE, ID_CENTRAL = p.ID_CENTRAL, FANTASIA = p.FANTASIA })
.SortBy(p => p.ID_CENTRAL).ToList();
It works fine to me.
I am trying to link up the RestaurantId in the RestaurantReservationEventsTbl with the RestaurantID in the RestaurantTbl to display reservations that are only made for the currently logged in restaurant.
I am receiving the following error in my code operator == cannot be applied to operands of type int and iqueryable int
Here is what I am doing in my home controller
var RestaurantIDRestaurantTbl = from r in db.Restaurants select r.RestaurantID;
//var listOfRestaurantsReservations = db.RestaurantReservationEvents.ToList();
var listOfRestaurantsReservations = db.RestaurantReservationEvents.Where(x => x.RestaurantID == RestaurantIDRestaurantTbl).ToList();
//return View(restaurants.Where(x => x.RestaurantEmailAddress == UserEmail).ToList());
//create partial view called _RestaurantReservation
return PartialView("_RestaurantReservations", listOfRestaurantsReservations);
You have to change your code to materialize the restaurantIds like this:
var RestaurantIDRestaurantTbl = (from r in db.Restaurants
select r.RestaurantID).ToList();
Then you may change the code as below for the comparison to work:
var listOfRestaurantsReservations = db.RestaurantReservationEvents.Where(x => RestaurantIDRestaurantTbl.Contains(x.RestaurantID)).ToList();
Anyway this is not the best solution. I will write another example for you, just try this example if it is working or not and let me know for the result.
I would considering changing the code as below to be much more efficient:
var listOfRestaurantsReservations = (from r in db.Restaurants
join e in db.RestaurantReservationEvents
on r.RestaurantID equals e.RestaurantID
//where r.RestaurantID == something //if where condition needed
select e).ToList();
If your tables are not connected with foreignkeys please consider to read this documentation here to make a better structure of the tables since they are related to each-other.
If your tables are related as in documentation article you might have something like that:
var RestaurantIDRestaurantTbl = db.Restaurants.SingleOrDefault(x => x.RestaurantID == something);
if(RestaurantIDRestaurantTbl != null)
{
var listOfRestaurantsReservations = RestaurantIDRestaurantTbl.RestaurantReservationEvents.ToList();
}
{
// This will give you a list of IDs
var RestaurantIDRestaurantTbl = db.Restaurants
.Select(p => p.RestaurantID)
.ToList();
// Using .Any() is a better choice instead of .Contains()
// .Contains is used to check if a list contains an item while .Any will look for an item in a list with a specific ID
var listOfRestaurantsReservations = db.RestaurantReservationEvents
.Where(p => RestaurantIDRestaurantTbl.Any(r => r.pRestaurantID == p))
.ToList();
}
What is the replacement of BaseQuery class in new version.
I couldn't find it anywhere.
My problem is how to generate syntax in c# for the search criteria as:
public class TextSearch
{
public string Headline {get;set;}
public string Summary {get;set;}
}
I need to search using text 'you', against two column as OR operator, Column 1 summary and Column 2 headline.
Earlier I was doing,
var orQuery = new List<BaseQuery>();
if (!string.IsNullOrEmpty(searchtext))
{
orQuery .Add(Query<TextSearch>.Terms("headline", searchOptions.text.ToLower().Split(' ')));
orQuery .Add(Query<TextSearch>.Terms("summary", searchOptions.text.ToLower().Split(' ')));
}
var finalQuery = new List<BaseQuery>();
finalQuery .Add(Query<TextSearch>.Bool(o => o.Should(orQuery.ToArray())));
Now this doesn't work.
Is there any better syntax for searching in new version.
The search criteria should using LIKE with OR,
e.g. summary LIKE '%you%' OR headling LIKE '%you%'
The documentation on the breaking changes in NEST 1.0 is pretty complete:
http://nest.azurewebsites.net/breaking-changes.html
We renamed BaseQuery to QueryContainer
The query can be:
client.Search<TextSearch>(s=>s
.Query(q=>
q.Terms("headline", words)
|| q.Terms("summary", words)
)
)
If words is empty or null that part is not rendered see the conditionless query section here:
http://nest.azurewebsites.net/nest/writing-queries.html
#Martijn Laarman
Since we have numerous filter criteria that will be dynamic based on user selected filter,
I'm constructing Filter Query in amethod based on user slelcted filter and then pass it to Search<> method as:
QueryContainer mainQuery = null;
if (!string.IsNullOrEmpty(searchOptions.SearchText))
{
var headline = Query<T>.Terms("headline", searchOptions.Headline.ToLower());
var summary = Query<T>.Terms("fullSummary", searchOptions.Summary.ToLower());
mainQuery &= (headline || summary);
}
if (searchOptions.FromDate != DateTime.MinValue && searchOptions.ToDate != DateTime.MinValue)
{
var dateFilter = Query<T>.Range(
r => r.OnField("processedDate").GreaterOrEquals(searchOptions.FromDate, ElasticDateFormat).LowerOrEquals(searchOptions.ToDate, ElasticDateFormat));
mainQuery &= dateFilter;
}
var result = Client.Search<T>(s => s.Query(mainQuery ).Size(Int32.MaxValue));
Here Client is a property that returns ElasticClient object.
Hope thats the correct way of doing.
I am getting the following exception:
The nested query is not supported. Operation1='Case' Operation2='Collect'
with this query
var Games = context.Games.Select(a => new GameModel
{
Members = (a.Type == 1 ? (a.UsersInGames.Where(b => b.GameID == a.ID && b.StatusID == 1).Select(c => new Member
{
ID = c.UserID,
email = c.UserInfo.EmailAddress,
screenName = c.UserInfo.ScreenName
})) :
(a.Teams.Where(b => b.GameID == a.ID).SelectMany(b => b.UsersInTeams.Where(c => c.StatusID == 1)).Select(d => new Member
{
ID = d.UserID,
email = d.UserInfo.EmailAddress,
screenName = d.UserInfo.ScreenName
)))
})
when I don't include the condition in selecting Members, the query works fine. Is there a way I can do the conditional inside the query?
You're overestimating the power of LINQ translation to SQL. Not everything is translatable and there is no compiler warning for that due to the way LINQ works.
Nested collections are usually either a) not supported or b) end up in horrible SELECT N+1 queries. What you ask EF to do is to return an object tree. SQL does not support tree like results so you run into the object-relational impedance mismatch and it hurts.
I advise you to fetch the nested collection data as a second, completely separate query. That allows you more control and is guaranteed to work.
As a non-essential side-note, you will probably not be able to convince EF to use the ?: operator over sequences. That is very hard to translate. Think how you would write this as SQL - very hard and convoluted.
It looks like Linq to EF doesn't support the following
context.Games.Select(g => new
{
Field = g.IsX? queryable1 : queryable2
});
But, here's a hack you can use to get it to work:
context.Games.Select(g => new
{
Field = queryable1.Where(q => g.IsX)
.Concat(queryable2.Where(q => !g.IsX))
});
I faced the same problem. The solution was to load both results and determine what to use after the query (I know it has performance downside), but at least you can do it temporarily if deadline attacks you:
At the LINQ side
var Games = context.Games.Select(a => new GameModel
{
// carries type1 results
Members = a.UsersInGames.Where(b => b.GameID == a.ID && b.StatusID == 1).Select(c => new Member
{
ID = c.UserID,
email = c.UserInfo.EmailAddress,
screenName = c.UserInfo.ScreenName
})),
//You need to create this temporary carrier to carry type 2 results
MembersOfType2 = a.Teams.Where(b => b.GameID == a.ID).SelectMany(b => b.UsersInTeams.Where(c => c.StatusID == 1)).Select(d => new Member
{
ID = d.UserID,
email = d.UserInfo.EmailAddress,
screenName = d.UserInfo.ScreenName
})))
})
}
After that you may loop Gamesand make the assignment Members = MembersOfType2 if Type == 1 for a certain game.
I had this error too. I had code like this:
var Games = context.Games.Select(a => new GameModel
{
Members = (!filters.GetDatailedDataToo ? null : new List<MemberModel>())
};
This error occurs when null is used in ? : operation.
This is not that case, written up here, but I've wasted lot of time, I think anyone uses this case, who searches this error text..
Is there a way to run .explain() or equivalent on Linq queries? I would want to know
The text of the actual JSON query
The output of .explain() (indexes used, etc)
It would also be nice to have the execution time of the query
You can get the Json easily enough if you have a query wrapper;
var qLinq = Query<T>.Where(x => x.name=="jim");
Console.WriteLine(qLinq.ToJson());
There's also an Explain() method on MongoCursor, so you could do this;
var exp = Collection.FindAs<T>(qLinq).Explain()
Console.WriteLine(exp.ToJson());
So if you want the time taken, "millis" is in there;
var msTaken = exp.First(x => x.Name == "millis").Value.AsInt32;
If you have an IQueryable, try something like this;
void Do(MongoCollection col, IQueryable iq)
{
// Json Mongo Query
var imq = (iq as MongoQueryable<Blob>).GetMongoQuery();
Console.WriteLine(imq.ToString());
// you could also just do;
// var cursor = col.FindAs(typeof(Blob), imq);
var cursor = MongoCursor.Create(typeof(Blob), col, imq, ReadPreference.Nearest);
var explainDoc = cursor.Explain();
Console.WriteLine(explainDoc);
}//Do()
If you want this functionality in a library, I just created a GitHub project entitled
MongoDB query helper for .NET
https://github.com/mikeckennedy/mongodb-query-helper-for-dotnet
It will:
Explain a LINQ query as a strongly typed object (does it use an index for example)
Convert a LINQ query to the JavaScript code run in MongoDB
Check it out and contribute if you find it interesting.
Yes, there is. It shows everything .explain does and has a boolean for verbosity (it includes the time it took to execute):
var database = new MongoClient().GetServer().GetDatabase("db");
var collection = database.GetCollection<Hamster>("Hamsters");
var explanation = collection.AsQueryable().Where(hamster => hamster.Name == "bar").Explain(true);
Console.WriteLine(explanation);
It doesn't show the query though. Here's an extension method for that:
public static string GetMongoQuery<TItem>(this IQueryable<TItem> query)
{
var mongoQuery = query as MongoQueryable<TItem>;
return mongoQuery == null ? null : mongoQuery.GetMongoQuery().ToString();
}
Usage:
var query = collection.AsQueryable().Where(hamster => hamster.Name == "bar").GetMongoQuery();
Console.WriteLine(query);
In mongodb 3 C# I used following:
var users = Mongo.db.GetCollection<User>("Users");
var r = users(m => m._id == yourIdHere)
.Project(m => new { m._id, m.UserName, m.FirstName, m.LastName })
.Limit(1);
Console.WriteLine(r.ToString());
Result:
find({ "_id" : ObjectId("56030e87ca42192008ed0955") }, { "_id" : 1, "UserName" : 1, "FirstName" : 1, "LastName" : 1 }).limit(1)