I have a Mongo database with lots of documents. All of the documents have a field called "source" which contains the origin name for the document. But a lot of old documents have this field containing "null" (because I hadn't have source by that time) string value. I want to select all those documents and fix this problem by replacing their "source = "null"" values by new values parsed from another fields of the aforementioned documents.
Here's what I'm doing to fix the this:
public void FixAllSources() {
Task.Run(async ()=> {
var filter = Builders<BsonDocument>.Filter.And(new List<FilterDefinition<BsonDocument>>() {
Builders<BsonDocument>.Filter.Exists("url"),
Builders<BsonDocument>.Filter.Ne("url", BsonNull.Value),
Builders<BsonDocument>.Filter.Eq("source", "null")
});
var result = await m_NewsCollection.FindAsync(filter);
var list = result.ToList();
list.ForEach(bson => {
bson["source"] = Utils.ConvertUrlToSource(bson["url"].AsString);
});
});
}
as you can see, I'm fetching all those documents and replacing their source field by a new value. So now I've got a List of correct BsonDocuments which I need to put back into the database.
Unfortunately, I'm stuck on this. The problem is that all of the "Update" methods require filters and I have no idea what filters should I pass there. I just need to put back all those updated documents, and that's it.
I'd appreciate any help :)
p.s.
I've came up with an ugly solution like this:
list.ForEach(bson => {
bson["source"] = Utils.ConvertUrlToSource(bson["url"].AsString);
try {
m_NewsCollection.UpdateOne( new BsonDocument("unixtime", bson["unixtime"]), new BsonDocument {{"$set", bson}},
new UpdateOptions {IsUpsert = true});
}
catch (Exception e) {
WriteLine(e.StackTrace);
}
});
It works for now. But I'd still like to know the better one in case I need to do something like this again. So I'm not putting my own solution as an answer
Related
Hi everybody in a previous post ( ListCollections with autorizedcollection ) I asked how to retrieve the name of the collections available in MongoDb'database. Finally the solution is much easier as expected and is :
var db = mongoUser.GetDatabase(databaseName);
var command = new CommandDocument { { "listCollections", 1 }, { "authorizedCollections", true }, {"nameOnly", true }};
var result = db.RunCommand<BsonDocument>(command);
the problem is I am not used to work with BsonDocument. I could cast the "result" into a BsonDocument or onto a string and then cut until I found the name of the solution. But it is the wrong way. Could someone help me for this case ?
you should not use CommandDocument since it's a Legacy API and you use not legacy code path in all other places. I think BsonDocument is the expected way to work with RunCommand. You can play with the above Deserialization suggestions but this will be just a step after RunCommand.
So I would expect something like this:
var command = new BsonDocument { { "listCollections", 1 }, { "authorizedCollections", true }, { "nameOnly", true } };
var result = db.RunCommand<BsonDocument>(command);
// any steps you want to process result including possible deserialization into typed view
I am developing my ASP.NET MVC application called eBookRepository that contains online books. Ebook has its own title, author etc. So right now I'm trying to implement my search mechanism. I must use Elasticsearch as search engine.
I have indexed my ebooks in this code, and it works.
Uri nodeLocation = new Uri("http://localhost:9200");
IConnectionPool connectionPool = new SniffingConnectionPool(new List<Uri> { nodeLocation });
ConnectionSettings settings = new ConnectionSettings(connectionPool).DefaultIndex("ebookrepository");
esClient = new ElasticClient(settings);
foreach (var ebook in ebooksService.GetAll())
{
IIndexResponse result = esClient.Index(ebook, i => i.Index("ebookrepository").Type("ebook").Id(ebook.ID));
}
Also if I search my ebooks by title, it works but only if search text is exactly same as ebook's title. Code doing that is here:
var search = esClient.Search<Ebook>(s => s.Source(sf => sf.IncludeAll()).Query(q => q.Term(p1 => p1.Title, searchString)));
searchString variable is string (text) that I type in text box on UI.
So I cant find similiar code like this above that should work like .contains method in C#, I was looking for right solution and I think I should use .Match instead of .Term (.Term return exact matching result), but I cant find right solution.
While I was looking for right solution a lot of questions and answers are in JSON format (I'm not good at it), I dont want that format, I need .NET code.
Based on the documentation you can use a Unstructured Search https://www.elastic.co/guide/en/elasticsearch/client/net-api/current/writing-queries.html#unstructured-search
use this
var hits = _context.Search<Ebook>(search string, new SearchUrlParameters { Pretty = true });
I'm trying to port over JavaScript code that interacts with a MongoDb to C# .NET and having problems with a delete/pull operation. I can't seem to figure out how to iterate over the Ponies array and remove a single ObjectId by matching to a passed in ObjectId.
{
"_id" : ObjectId("388e8a66fe2af4e35c60e"),
"Location" : "rainbowland",
"Ponies" : [
ObjectId("388e8a66fe2af4e35c24e83c"),
ObjectId("388e8a66fe2af4e35c24e860"),
ObjectId("388e8a66fe2af4e35c24e83d")
]
}
I've tried several different ways based on what I've found online but nothing seems to work. When I check the collection to see if 388e8a66fe2af4e35c24e860 was removed from the Ponies array I see that it wasn't removed. Everytime I execute the code and look at the ModifiedCount for resultPonies it shows zero. Two examples of what I've tried doing are below.
var pony = new Pony() { Id = new ObjectId("388e8a66fe2af4e35c24e860") }
var pullPonies = Builders<Ranch>.Update.PullFilter(x => x.Ponies,
y => y.Id == pony.Id);
var filterPonies = Builders<Ranch>.Filter.Where(x => true);
var resultPonies = _context.Ranches.UpdateMany(filterPonies, pullPonies);
OR
var pullPonies = Builders<BsonDocument>.Update.PullFilter("Ponies",
Builders<ObjectId>.Filter.Eq("ObjectId", pony.Id));
var filterPonies = Builders<BsonDocument>.Filter.Where(x => true);
var resultPonies = _context.Ranches.UpdateMany(filterPonies, pullPonies);
Here is the JavaScript code that I believe works but haven't been able to test yet.
db.collection("Ranches").update({}, {$pull: {Ponies: pony._id}}, {multi: true});
Ok, I found a solution for the problem. Since I'm not actually going to be filtering within the array of objects, they are all ObjectIds in a BsonArray, I need to find where the value in the array matches the given ObjectId. In those cases the array item should be pulled out. If the object in the array had other properties then I would probably want to use the PullFilter. But in this case I don't need to filter the additional level. That is at least what I believe I was doing wrong. Here are the solutions
var ponyId = new ObjectId("388e8a66fe2af4e35c24e860");
var pullPonies = Builders<Ranch>.Update.Pull(x => x.Ponies, ponyId);
// This line is to retrieve all Ranch objects in the collection
var filterPonies = Builders<Ranch>.Filter.Where(x => true);
var resultPonies = _context.Ranches.UpdateMany(filterPonies, pullPonies);
Or
var ponyId = new ObjectId("388e8a66fe2af4e35c24e860");
var pullPonies = Builders<BsonDocument>.Update.Pull("Ponies", ponyId));
// This line is to retrieve all Ranch objects in the collection
var filterPonies = Builders<BsonDocument>.Filter.Where(x => true);
var resultPonies = _context.Ranches.UpdateMany(filterPonies, pullPonies);
Using the example code from the Unity Developer Guide | Parse
# https://www.parse.com/docs/unity_guide#objects-updating
// Create the object.
var gameScore = new ParseObject("GameScore")
{
{ "score", 1337 },
{ "playerName", "Sean Plott" },
{ "cheatMode", false },
{ "skills", new List<string> { "pwnage", "flying" } },
};
gameScore.SaveAsync().ContinueWith(t =>
{
// Now let's update it with some new data. In this case, only cheatMode
// and score will get sent to the cloud. playerName hasn't changed.
gameScore["cheatMode"] = true;
It just adds a new row and leaves the original row unchanged.
I guess i'm thinking Parse would do something "SQL like" such as UPDATE where primaryKey = 123.
Searching for an answer i found this code #
https://parse.com/questions/updating-a-field-without-retrieving-the-object-first, but there was no example in C#. All attempts to port this to C# result in multiple syntax errors.
UnityScript:
// Create a pointer to an object of class Point with id dlkj83d
var Point = Parse.Object.extend("Point");
var point = new Point();
point.id = "dlkj83d";
// Set a new value on quantity
point.set("quantity", 6);
// Save
point.save(null, {
success: function(point) {
// Saved successfully.
},
error: function(point, error) {
// The save failed.
// error is a Parse.Error with an error code and description.
}
});
Does Parse have some way to update a row that already exists using C#? And where is it in the docs? And how can their own example be so useless?
One of the posts related to my question stated "retrieve the object, then write it back with the changes" and i had not the faintest idea how to execute the stated objective (especially after the epic fail of Parse Documentation's example code)
Here is what i have been able to figure out and make work:
var query = new ParseQuery<ParseObject>("Tokens")
.WhereEqualTo ("objectId", "XC18riofu9");
query.FindAsync().ContinueWith(t =>
{
var tokens = t.Result;
IEnumerator<ParseObject> enumerator = tokens.GetEnumerator();
enumerator.MoveNext();
var token = enumerator.Current;
token["power"] = 20;
return token.SaveAsync();
}).Unwrap().ContinueWith(t =>
{
// Everything is done!
//Debug.Log("Token has been updated!");
});
the first part retrieves the object with the stated objectId, the second part sets the fields in the object. The third part reports all is well with the operation.
it's a monkey see, monkey do understanding at this point being that i do not understand the finer points in the code.
the code can be tested by creating a class named "Tokens". in that class create a tokenName field and a power field. make a few rows with Fire, water, mud as the tokenNames. Replace the objectId in the .WhereEqualTo clause with a valid objectId or any other search parameters you like. Execute the code and observe the changes in the Parse Data Browser.
For extra credit create the class required to implement the example code from the Chaining Tasks Together section of Parse's Documentation.
https://www.parse.com/docs/unity_guide#tasks-chaining
I am trying to update a row in a (typed) MongoDB collection with the C# driver. When handling data of that particular collection of type MongoCollection<User>, I tend to avoid retrieving sensitive data from the collection (salt, password hash, etc.)
Now I am trying to update a User instance. However, I never actually retrieved sensitive data in the first place, so I guess this data would be default(byte[]) in the retrieved model instance (as far as I can tell) before I apply modifications and submit the new data to the collection.
Maybe I am overseeing something trivial in the MongoDB C# driver how I can use MongoCollection<T>.Save(T item) without updating specific properties such as User.PasswordHash or User.PasswordSalt? Should I retrieve the full record first, update "safe" properties there, and write it back? Or is there a fancy option to exclude certain fields from the update?
Thanks in advance
Save(someValue) is for the case where you want the resulting record to be or become the full object (someValue) you passed in.
You can use
var query = Query.EQ("_id","123");
var sortBy = SortBy.Null;
var update = Update.Inc("LoginCount",1).Set("LastLogin",DateTime.UtcNow); // some update, you can chain a series of update commands here
MongoCollection<User>.FindAndModify(query,sortby,update);
method.
Using FindAndModify you can specify exactly which fields in an existing record to change and leave the rest alone.
You can see an example here.
The only thing you need from the existing record would be its _id, the 2 secret fields need not be loaded or ever mapped back into your POCO object.
It´s possible to add more criterias in the Where-statement. Like this:
var db = ReferenceTreeDb.Database;
var packageCol = db.GetCollection<Package>("dotnetpackage");
var filter = Builders<Package>.Filter.Where(_ => _.packageName == packageItem.PackageName.ToLower() && _.isLatestVersion);
var update = Builders<Package>.Update.Set(_ => _.isLatestVersion, false);
var options = new FindOneAndUpdateOptions<Package>();
packageCol.FindOneAndUpdate(filter, update, options);
Had the same problem and since I wanted to have 1 generic method for all types and didn't want to create my own implementation using Reflection, I end up with the following generic solution (simplified to show all in one method):
Task<bool> Update(string Id, T item)
{
var serializerSettings = new JsonSerializerSettings()
{
NullValueHandling = NullValueHandling.Ignore,
DefaultValueHandling = DefaultValueHandling.Ignore
};
var bson = new BsonDocument() { { "$set", BsonDocument.Parse(JsonConvert.SerializeObject(item, serializerSettings)) } };
await database.GetCollection<T>(collectionName).UpdateOneAsync(Builders<T>.Filter.Eq("Id", Id), bson);
}
Notes:
Make sure all fields that must not update are set to default value.
If you need to set field to default value, you need to either use DefaultValueHandling.Include, or write custom method for that update
When performance matters, write custom update methods using Builders<T>.Update
P.S.: It's obviously should have been implemented by MongoDB .Net Driver, however I couldn't find it anywhere in the docs, maybe I just looked the wrong way.
Well there are many ways to updated value in mongodb.
Below is one of the simplest way I choose to update a field value in mongodb collection.
public string UpdateData()
{
string data = string.Empty;
string param= "{$set: { name:'Developerrr New' } }";
string filter= "{ 'name' : 'Developerrr '}";
try
{
//******get connections values from web.config file*****
var connectionString = ConfigurationManager.AppSettings["connectionString"];
var databseName = ConfigurationManager.AppSettings["database"];
var tableName = ConfigurationManager.AppSettings["table"];
//******Connect to mongodb**********
var client = new MongoClient(connectionString);
var dataBases = client.GetDatabase(databseName);
var dataCollection = dataBases.GetCollection<BsonDocument>(tableName);
//****** convert filter and updating value to BsonDocument*******
BsonDocument filterDoc = BsonDocument.Parse(filter);
BsonDocument document = BsonDocument.Parse(param);
//********Update value using UpdateOne method*****
dataCollection.UpdateOne(filterDoc, document);
data = "Success";
}
catch (Exception err)
{
data = "Failed - " + err;
}
return data;
}
Hoping this will help you :)