Question

I have the following code I wrote:

        Analyzer analyzer = new StandardAnalyzer(Version.LUCENE_29);
        IndexWriter writer = new IndexWriter(directory, analyzer, true, IndexWriter.MaxFieldLength.UNLIMITED);
        Document doc = new Document();

        foreach (string fieldName in Request.Form)
        {
            if (fieldName == "channelID" && string.IsNullOrEmpty(Request["channelID"]))
            {
                List<long> channelIDS = new List<long>();
                IndexReader indexReader = IndexReader.Open(directory, true);
                TermEnum te = indexReader.Terms(new Term("ID"));
                do
                {
                    Term t = te.Term();
                    if (t == null || t.Field() != "channelID") break;
                    channelIDS.Add(long.Parse(t.Text()));
                } while (te.Next());
                te.Close();

                long nextAvailable = channelIDS.Concat(new[] { long.MaxValue })
                                            .OrderBy(x => x)
                                            .Select((value, index) => new { value, index })
                                            .Where(pair => pair.value != pair.index)
                                            .Select(pair => pair.index)
                                            .First();
                doc.Add(new Field(fieldName, nextAvailable.ToString(), Field.Store.YES, Field.Index.ANALYZED));
            }
            else
            {
                doc.Add(new Field(fieldName, Request.Form[fieldName], Field.Store.YES, Field.Index.ANALYZED));
            }
        }

        writer.AddDocument(doc);
        writer.Optimize();
        writer.Close();

The document already in the index has a channelID with a value of 0, and all other fields empty.

I have verified that the data fed to the document has a different channelID (even due all the other fields are empty, same as the existing document.

For some reason, the code updates the single document I already have in Lucene,
instead of adding a new one… what am I missing here?

Answer 1

In your code, you are re-creating the index with every run/method-call. So your previous index is deleted.

IndexWriter writer = new IndexWriter(directory, analyzer, true, IndexWriter.MaxFieldLength.UNLIMITED);

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BTW, terms are stored sorted in lucene index. You can do your calculations while enumerating the terms.