Having trouble with a very basic search -- no results - c#

I have Elasticsearch up and running. Using Sense within Marvel, I am able to get a result, with this query:
GET _search
{
"query": {
"query_string": {
"query": "massa"
}
}
}
My c# code, trying to recreate the above:
var node = new Uri("http://localhost:9200");
var settings = new ConnectionSettings(node).SetDefaultIndex("mediaitems");
var client = new ElasticClient(settings);
var results = client.Search<stuff>(s => s
.Query(qs => qs.QueryString(q => q.Query("massa"))));
var d = results.Documents;
But unfortunately I'm not getting any results, nothing in "results.Documents". Any suggestions? Maybe a way to see the generated json? What is the simplest way to just query everything in an index? Thanks!

Even though your search results are going to be mapped to the proper type because you are using .Search<stuff>, you still need to set the default type as part of your query.
var node = new Uri("http://localhost:9200");
var settings = new ConnectionSettings(node).SetDefaultIndex("mediaitems");
var client = new ElasticClient(settings);
var results = client.Search<stuff>(s => s
.Type("stuff") //or .Type(typeof(stuff)) if you have decorated your stuff class correctly.
.Query(qs => qs.QueryString(q => q.Query("massa"))));
var d = results.Documents;
Additionally, your results response contains a ConnectionStatus property. You can interrogate this property to see the Request and Response to/from Elasticsearch to see if your query is being executed as you expect.
Update: You can also set a default type the index settings as well.
var settings = new ConnectionSettings(node).SetDefualtIndex("mediaitems");
settings.MapDefaultTypeIndices(d=>d.Add(typeof(stuff), "mediaitems");

You can also check nest raw client
var results = client.Raw.SearchPost("mediaitems", "stuff", new
{
query = new
{
query_string = new
{
query = "massa"
}
}
});

You can get the values of search request URL and JSON request body as under:
var requestURL = response.RequestInformation.RequestUrl;
var jsonBody = Encoding.UTF8.GetString(response.RequestInformation.Request);
You can find other useful properties in RequestInformation for debugging.

Related

Nest Client c# 7.0 for elastic search removing Aliases

So with the latest update with Elastic Search 6, The C# Client was also upgraded too. But i can't figure out how to write this code the new way with the new Client Nest 7. I just need to rewrite this code
var indexExists = Client.IndexExists(CurrentAliasName).Exists;
Client.Alias(aliases => {
if (indexExists)
{
var oldIndices = Client.GetIndicesPointingToAlias(CurrentAliasName);
var indexName = oldIndices.First().ToString();
//remove alias from live index
aliases.Remove(a => a.Alias(CurrentAliasName).Index("*"));
}
return aliases.Add(a => a.Alias(CurrentAliasName).Index(CurrentIndexName));
});
The APIs have been moved into API groupings
var client = new ElasticClient();
var CurrentAliasName = "alias_name";
var CurrentIndexName = "index_name";
var indexExists = client.Indices.Exists(CurrentAliasName).Exists;
client.Indices.BulkAlias(aliases =>
{
if (indexExists)
{
var oldIndices = client.GetIndicesPointingToAlias(CurrentAliasName);
var indexName = oldIndices.First().ToString();
//remove alias from live index
aliases.Remove(a => a.Alias(CurrentAliasName).Index("*"));
}
return aliases.Add(a => a.Alias(CurrentAliasName).Index(CurrentIndexName));
});
You can also reference Nest.7xUpgradeAssistant package and keep using the same methods as in 6.x to help with the move to 7.x. You'll get compiler warnings with messages to indicate where the new API methods are located.

How to avoid posting duplicates into elasticsearch using Nest .NET 6.x?

When data from a device goes into the elastic there are duplicates. I like to avoid this duplicates. I'm using a object of IElasticClient, .NET and NEST to put data.
I searched for a method like ElasticClient.SetDocumentId(), but cant find.
_doc doc = (_doc)obj;
HashObject hashObject = new HashObject { DataRecordId = doc.DataRecordId, TimeStamp = doc.Timestamp };
// hashId should be the document ID.
int hashId = hashObject.GetHashCode();
ElasticClient.IndexDocumentAsync(doc);
I would like to update the data set inside the Elastic instead of adding one more same object right now.
Assuming the following set up
var pool = new SingleNodeConnectionPool(new Uri("http://localhost:9200"));
var settings = new ConnectionSettings(pool)
.DefaultIndex("example")
.DefaultTypeName("_doc");
var client = new ElasticClient(settings);
public class HashObject
{
public int DataRecordId { get; set; }
public DateTime TimeStamp { get; set; }
}
If you want to set the Id for a document explicitly on the request, you can do so with
Fluent syntax
var indexResponse = client.Index(new HashObject(), i => i.Id("your_id"));
Object initializer syntax
var indexRequest = new IndexRequest<HashObject>(new HashObject(), id: "your_id");
var indexResponse = client.Index(indexRequest);
both result in a request
PUT http://localhost:9200/example/_doc/your_id
{
"dataRecordId": 0,
"timeStamp": "0001-01-01T00:00:00"
}
As Rob pointed out in the question comments, NEST has a convention whereby it can infer the Id from the document itself, by looking for a property on the CLR POCO named Id. If it finds one, it will use that as the Id for the document. This does mean that an Id value ends up being stored in _source (and indexed, but you can disable this in the mappings), but it is useful because the Id value is automatically associated with the document and used when needed.
If HashObject is updated to have an Id value, now we can just do
Fluent syntax
var indexResponse = client.IndexDocument(new HashObject { Id = 1 });
Object initializer syntax
var indexRequest = new IndexRequest<HashObject>(new HashObject { Id = 1});
var indexResponse = client.Index(indexRequest);
which will send the request
PUT http://localhost:9200/example/_doc/1
{
"id": 1,
"dataRecordId": 0,
"timeStamp": "0001-01-01T00:00:00"
}
If your documents do not have an id field in the _source, you'll need to handle the _id values from the hits metadata from each hit yourself. For example
var searchResponse = client.Search<HashObject>(s => s
.MatchAll()
);
foreach (var hit in searchResponse.Hits)
{
var id = hit.Id;
var document = hit.Source;
// do something with them
}
Thank you very much Russ for this detailed and easy to understand description! :-)
The HashObject should be just a helper to get a unique ID from my real _doc object. Now I add a Id property to my _doc class and the rest I will show with my code below. I get now duplicates any more into the Elastic.
public void Create(object obj)
{
_doc doc = (_doc)obj;
string idAsString = doc.DataRecordId.ToString() + doc.Timestamp.ToString();
int hashId = idAsString.GetHashCode();
doc.Id = hashId;
ElasticClient.IndexDocumentAsync(doc);
}

How to find matching 'StartsWith' documents on classless MongoDB using C# driver

I have documents:
{"handler":"north"}
{"handler":"south"}
{"handler":"west"}
{"handler":"east"}
I want to find a matching handler from a given string input, e.g. "westtown" and expects the handler will be "west".
Please help, my code below does not work.
String inputstring = "westtown";
IMongoCollection<BsonDocument> collection = null;
List<BsonDocument> pages = null;
try
{
collection = db.GetCollection<BsonDocument>("handlers");
pages = await collection.Find(x => (inputstring.StartsWith(x["handler"].AsString))).ToListAsync<BsonDocument>();
}
...
I use classless scheme, so I use BsonDocument on the dynamic.
AFAIK, In MongoDB you can find it with $where operator like this:
{ $where: "'westtown'.startsWith(this.handler)" }
So, I think in c# you can do it with something like this:
var filter =
new BsonDocument(
new Dictionary<string, BsonValue>
{
{
"$where",
new BsonString("'westtown'.startsWith(this.handler)")
}
});
var result = col.Find(filter).ToList();

Insert collection into List from MongoDB

I try to get all data from collection into MongoDB server using C# driver.
The idea is connect to the server and get all collection than insert into list of class.
List<WatchTblCls> wts;
List<UserCls> users;
List<SymboleCls> syms;
public WatchTbl()
{
InitializeComponent();
wts = new List<WatchTblCls>();
users = new List<UserCls>();
syms = new List<SymboleCls>();
}
public async void getAllData()
{
client = new MongoClient("mongodb://servername:27017");
database = client.GetDatabase("WatchTblDB");
collectionWatchtbl = database.GetCollection<WatchTbl>("Watchtbl");
collectionUser = database.GetCollection<UserCls>("Users");
collectionSymbole = database.GetCollection<SymboleCls>("Users");
var filter = new BsonDocument();
using (var cursor = await collectionWatchtbl.FindAsync(filter))
{
while (await cursor.MoveNextAsync())
{
var batch = cursor.Current;
foreach (var document in batch)
{
wts.Add(new WatchTblCls(document["_id"], document["userId"], document["wid"], document["name"], document["Symboles"]));
}
}
}
}
I get this error under
wts.Add(new WatchTblCls(document["_id"], document["userId"], document["wid"], document["name"], document["Symboles"]));
Cannot apply indexing with [] to an expression of type 'WatchTbl'
I don't understand the reason behind using WatchTbl and WatchTblCls both together. Is WatchTblCls a model for the entity WatchTbl here? Im not sure.
In any case. If you go for aggregation and want to convert WatchTbl collection to WatchTblCls list, your desired solution might look like the following. I don't know the defiitions of the classes so I'm assuming:
var client = new MongoClient("mongodb://servername:27017");
var database = client.GetDatabase("WatchTblDB");
var collectionWatchtbl = database.GetCollection<WatchTbl>("Watchtbl");
var collectionUser = database.GetCollection<UserCls>("Users");
var collectionSymbole = database.GetCollection<SymboleCls>("Users");
var list = collectionWatchtbl.AsQueryable().Select(x => new WatchTblCls() {
id = x.id,
userId = x.userId,
.....
});
If you can use the same WatchTbl class and still want to load the full collection to a local List (which is definitely not a good idea):
List<WatchTbl> list = await collectionWatchtbl.Find(x => true).ToListAsync();

Breeze work-around for multi valued property queries

I'm trying to assemble ad-hoc queries to Breeze.
I have a physician.contact.addresses relationship.
When I try:
myPred = new pred('contact.addresses.street1', op.StartsWith, "a");
And execute it I get:
"The parent value for a property access of a property 'Addresses' is not a single value. Property access can only be applied to a single value."
To try a work-around I've tried parsing out those many-relationships and am passing it to the breeze controller in .withParameters like this:
var criteriaStr = toManyArray.length ? ko.utils.stringifyJson(toManyArray) : "";
query = query.withParameters({ searchParms: criteriaStr });
where toManyArray is an array of fieldName:value pairs.
on the controller side:
[HttpGet]
public IQueryable<Physician> Physician(string searchParms = null)
{
if (searchParms != null)
{
var ser = new JavaScriptSerializer();
var searchCritAry = ser.Deserialize<String[]>(searchParms);
foreach (var aryItem in searchCritAry)
{
// aryItem looks like this:
// f_str_street_from_addresses:a
var predEnt = aryItem.Split(':')[0].Split('_')[4];
var predField = aryItem.Split(':')[0].Split('_')[2];
var predVal = aryItem.Split(':')[1];
switch (predEnt)
{
case "addresses":
switch (predField)
{
case "street":
//physPool =
_contextProvider.Context.Physicians
.Where(p => p.Contact.Addresses.Any(a => a.Street1.StartsWith(predVal)));
break;
case "street2":
//physPool =
_contextProvider.Context.Physicians
.Where(p => p.Contact.Addresses.Any(a => a.Street2.StartsWith(predVal)));
break;
}
break;
}
}
// here I want to combine the .Where clauses from above with the breeze preds
return _contextProvider.Context.Physicians;
}
return _contextProvider.Context.Physicians;
}
It's not working and only returning a selection using the predicates that are passed in the normal way through Breeze's query. I don't see how to pass the filtered IQueryable to Breeze's _contextProvider.
Thanks for any suggestions.
Take a look at the new "any/all" support in Breeze ( as of version 1.4.7). Some examples may be found here: http://www.breezejs.com/documentation/query-examples
You can construct your query/predicate like this:
var pred = new Breeze.Predicate('contact.addresses', "any", 'street1', op.StartsWith, "a");
var query = EntityQuery.from("Physicians").where(pred);
or simply
var query = EntityQuery.from("Physicians")
.where("contact.addresses", "any", "street1", "startsWith", 'a')
You may want to add an expand if you want the contact and address information sent down as well.
query = query.expand("contact.addresses");
If you have a need for nested any/all expressions you may need to add the following configuration to your BreezeController to determine just how deep you want to allow the expressions to go (2 in the example below):
[BreezeController(MaxAnyAllExpressionDepth = 2)]

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