I have ContentSearch code that works and runs fine using Lucene. When I switch the configs over to Solr, the query fails, and the logs state that the field I'm using in the query doesn't exist.

public IEnumerable<ID> Tags { get; set; }

16644 13:34:20 ERROR Solr Error : ["undefined field tags"] - Query attempted: [((_template:(2d7ad1cb107e44158690c03e0b65f90c) AND -_name:("__Standard Values")) AND tags:(fc8ac78af9aa495fb4ee08aca0444e1b))]

Note that the error says 'undefined field tags', but really, this should be tags_sm when Sitecore adds the suffix to the query. Changing [IndexField("tags")] to [IndexField("tags_sm")] gets it working....but now my code is Search Provider dependent.

Is there something I'm missing to make this work without the suffix? I thought Sitecore would automatically add it in there?

Here is how the query looks:-

var filterPredicate = PredicateBuilder.True<ArticleSearchResultItem>()
                .And(x => x.TemplateId == IArticlePageItemConstants.TemplateId && x.Name != "__Standard Values");

if (parameters.TagId != (ID)null && parameters.TagId != ID.Null)
   filterPredicate = filterPredicate.And(x => x.Tags.Contains(parameters.TagId));

var queryable = searchContext.GetQueryable<ArticleSearchResultItem>();
var searchResults = queryable

This is on Sitecore 8.1 Update-2, using Solr 6.1.0. Thanks.

  • I have always had to modify my custom index fields when switching from Lucene to SOLR. I will be interested if is it possible to do it without. I do notice in habitat switching from 8 to 9 (now SOLR) they did not change the field names. github.com/Sitecore/Habitat/blob/master/src/Foundation/Indexing/…
    – Chris Auer
    Commented Oct 3, 2018 at 17:52
  • Try to change the public IEnumerable<ID> to public IEnumerable<string> or public List<string> Commented Oct 4, 2018 at 20:00
  • I've had the same issue too. Have you tried adding an explicit mapping for IEnumerable<ID> in the config, something like this? <typeMatch type="System.Collections.Generic.IEnumerable`1[Sitecore.Data.ID]" typeName="idCollection" fieldNameFormat="{0}_sm" multiValued="true" settingType="Sitecore.ContentSearch.SolrProvider.SolrSearchFieldConfiguration, Sitecore.ContentSearch.SolrProvider" />
    – mikaelnet
    Commented Feb 26, 2019 at 10:02
  • Maybe this can be solved with a type converter too. I haven't tried it, as I've opted for the approach of adding field type, such as _sm. [TypeConverter(typeof(IndexFieldEnumerableConverter))]
    – mikaelnet
    Commented Feb 26, 2019 at 10:07
  • 1
    The other way is to add "tags" field in solr schema.xml and then use of <copyField source="tags_sm" dest="tags" />. This way you don't need to change your code. Commented Oct 22, 2019 at 10:35

2 Answers 2


You must have a typematch for type IEnumerable<ID> in your index configuration to make this work. So, create a patch file and include typematch as follow

<typeMatch typeName="idIEnumerable"        type="System.Collections.Generic.IEnumerable`1[[Sitecore.Data.ID, Sitecore.Kernel]]"         fieldNameFormat="{0}_sm"  multiValued="true"    settingType="Sitecore.ContentSearch.SolrProvider.SolrSearchFieldConfiguration, Sitecore.ContentSearch.SolrProvider"  />

or if you want your property to be List<ID> then have below typematch included

<typeMatch typeName="idList"        type="System.Collections.Generic.List`1[[Sitecore.Data.ID, Sitecore.Kernel]]"       fieldNameFormat="{0}_sm"  multiValued="true"    settingType="Sitecore.ContentSearch.SolrProvider.SolrSearchFieldConfiguration, Sitecore.ContentSearch.SolrProvider"  />


tags would get converted to tags_sm in query only if there is a typematch found for that particular type (IEnumerable<ID> in your case). You can find out the same by looking at typematchs section for your index configuration in showconfig.aspx.

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Behind the scene SolrSearchConfiguration class reads this configuration and it sets the strongly type by calling Type.GetType(type) and that works fine with simple types like DateTime, Int32, Int64, String, String[], List etc..

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But when type is complex such as IEnumerable<ID> then Type.GetType() method expect a AssemblyQualifiedName. You can get AssemblyQualifiedName for any type by just calling type.GetType() method.


You could change the default field mapping in your index configuration (i would create a custom indexconfiguration based on the default):


and remove the suffix from the format (this example is for text fields, you should change it for ID-types):


    settingType="Sitecore.ContentSearch.SolrProvider.SolrSearchFieldConfiguration, Sitecore.ContentSearch.SolrProvider" />

without suffix:

        settingType="Sitecore.ContentSearch.SolrProvider.SolrSearchFieldConfiguration, Sitecore.ContentSearch.SolrProvider" />

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