Solr索引中缺少Id字段

Question

I just find out that my Solr index doesn't contain a _id field. and it is not possible to get item id. UniqueId is present but this is not really useful.

public class MyClass
{
    [IndexField(BuiltinFields.UniqueId)]
    public string UniqueId { get; set; }

    [IndexField(BuiltinFields.ID)]
    public int Id { get; set; }
}

How to add item id to Solr index ? What should I add to schema.xml ? Is next string would be enough ?

<field name="_id" type="string" indexed="true" stored="true" required="true" />

If yes why Sitecore doesn't include it during build schema.xml file for Solr ?

It seems that it could be an issue with duplication records in search result that I have as well :)

Answer 1

As Richard answered, there is a _group field in Solr. If you want it to be translated automatically into ID object, you can use:

[TypeConverter(typeof (IndexFieldIDValueConverter))]
[IndexField("_group")]
public virtual ID ItemId { get; set; }

Remember that if you have multiple versions or language versions, _group field will not be enough, cause there will be multiple documents with the same _group (id). In that case you may want to use UniqueId - it contains information about id, version, language and database:

[IndexField("_uniqueid")]
public virtual string UniqueId { get; set; }

And then to get the Item use:

private Item _innerItem;
public virtual Item GetItem()
{
    if (_innerItem == null)
    {
        ItemUri uri = new ItemUri(UniqueId);
        _innerItem = Factory.GetDatabase(uri.DatabaseName).GetItem(uri.ItemID, uri.Language, uri.Version);
    }
    return _innerItem;
}

Or you can just inherit your MyClass from Sitecore.ContentSearch.SearchTypes.SearchResultItem and you will have all the built in fields there.

Answer 2

In SOLR the Item Id field is called _group - this should be added to your schema.xml file when you generate it.

If its not there, this is the definition I have:

<field name="_group" stored="true" indexed="true" type="string"/>

The UniqueId field contains the ItemId along with the version and language of the item.