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Elasticsearch.Net and NEST: the .NET clients [5.x] » Client Concepts - NEST » Indices paths
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Indices pathsedit

Some APIs in Elasticsearch take one or many index name or a special _all marker to send the request to all the indices In NEST, this is encoded using Indices.

Implicit Conversionedit

Several types implicitly convert to Indices

Nest.Indices singleIndexFromString = "name";
Nest.Indices multipleIndicesFromString = "name1, name2";
Nest.Indices multipleIndicesFromStringArray = new [] { "name1", "name2" };
Nest.Indices allFromString = "_all";
Nest.Indices allWithOthersFromString = "_all, name2";
singleIndexFromString.Match(
    all => all.Should().BeNull(),
    many => many.Indices.Should().HaveCount(1).And.Contain("name")
);
multipleIndicesFromString.Match(
    all => all.Should().BeNull(),
    many => many.Indices.Should().HaveCount(2).And.Contain("name2")
);
allFromString.Match(
    all => all.Should().NotBeNull(),
    many => many.Indices.Should().BeNull()
);
allWithOthersFromString.Match(
    all => all.Should().NotBeNull(),
    many => many.Indices.Should().BeNull()
);
multipleIndicesFromStringArray.Match(
    all => all.Should().BeNull(),
    many => many.Indices.Should().HaveCount(2).And.Contain("name2")
);

Using Nest.Indicesedit

To ease creating IndexName or Indices from expressions, there is a static Nest.Indices class you can use

Specifying a single indexedit

A single index can be specified using a CLR type or a string

var client = TestClient.Default;

var singleString = Index("name1"); 

var singleTyped = Index<Project>(); 

ISearchRequest singleStringRequest = new SearchDescriptor<Project>().Index(singleString);

ISearchRequest singleTypedRequest = new SearchDescriptor<Project>().Index(singleTyped);

((IUrlParameter)singleStringRequest.Index).GetString(this.Client.ConnectionSettings).Should().Be("name1");

((IUrlParameter)singleTypedRequest.Index).GetString(this.Client.ConnectionSettings).Should().Be("project");

var invalidSingleString = Index("name1, name2");

specifying a single index using a string

specifying a single index using a type

an invalid single index name

Specifying multiple indicesedit

Similarly to a single index, multiple indices can be specified using multiple CLR types and multiple strings

var manyStrings = Index("name1", "name2"); 

var manyTypes = Index<Project>().And<Developer>(); 

var client = TestClient.Default;

ISearchRequest manyStringRequest = new SearchDescriptor<Project>().Index(manyStrings);

ISearchRequest manyTypedRequest = new SearchDescriptor<Project>().Index(manyTypes);

((IUrlParameter)manyStringRequest.Index).GetString(this.Client.ConnectionSettings).Should().Be("name1,name2");

((IUrlParameter)manyTypedRequest.Index).GetString(this.Client.ConnectionSettings).Should().Be("project,devs"); 

manyStringRequest = new SearchDescriptor<Project>().Index(new[] { "name1", "name2" });

((IUrlParameter)manyStringRequest.Index).GetString(this.Client.ConnectionSettings).Should().Be("name1,name2");

manyStringRequest = new SearchDescriptor<Project>().Type(new[] { "name1", "name2" });

((IUrlParameter)manyStringRequest.Type).GetString(this.Client.ConnectionSettings).Should().Be("name1,name2");

specifying multiple indices using strings

specifying multiple indices using types

The index names here come from the Connection Settings passed to TestClient. See the documentation on Index Name Inference for more details.

Specifying All Indicesedit

Elasticsearch allows searching across multiple indices using the special _all marker.

NEST exposes _all with Indices.All and Indices.AllIndices. Why expose it in two ways, you ask? Well, you may be using both Nest.Indices and Nest.Types in the same file and you may also be using C#6 static imports too; in this scenario, All becomes ambiguous between Indices.All and Types.All, so the _all marker is exposed as Indices.AllIndices to alleviate this ambiguity

var indicesAll = All;

var allIndices = AllIndices;

var client = TestClient.Default;

ISearchRequest indicesAllRequest = new SearchDescriptor<Project>().Index(indicesAll);

ISearchRequest allIndicesRequest = new SearchDescriptor<Project>().Index(allIndices);

((IUrlParameter)indicesAllRequest.Index).GetString(this.Client.ConnectionSettings).Should().Be("_all");

((IUrlParameter)allIndicesRequest.Index).GetString(this.Client.ConnectionSettings).Should().Be("_all");
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