How to Implement MongoDB TextSearch with C#

Table of Contents

1. Introduction
2. Add Text Index to the Collection
3. Call Text Search Functions
4. MongoDB Version Requirements
5. Conclusion

Introduction

This post provides a simple code snippet to implement MongoDB text search using C#. MongoDB needs to be version 2.6 or higher for text search to work properly.

Add Text Index to the Collection

First, add a text index to the collection:

// add text index to the item
 string[] textIndex = new string[] { "Name", "ListItem.Name", "ListItem.Name2", "AnotherListItem.Name"};
            string indexName = string.Join("_text_", textIndex) + "_text";
            if (collection.IndexExistsByName(indexName))
            {
                collection.DropIndexByName(indexName);
            }
            collection.EnsureIndex(new IndexKeysBuilder().Text(textIndex));

Call Text Search Functions

Now, call the text search functions:

var textSearchCommand = new CommandDocument
            {
              { "text", "CollectionName" },
              { "search", yourSearchTargetText}
            };

            var commandResult = Mongo.Database.RunCommand(textSearchCommand);
            var yourCollectionItems = commandResult.Response["results"].AsBsonArray.Select(o =>
            {
                return BsonSerializer.Deserialize(o["obj"].AsBsonDocument);
            });

MongoDB Version Requirements

MongoDB needs to be version 2.6 or higher for text search functionality to work correctly.

Conclusion

That's it — now you can enjoy text search in MongoDB with C#. By creating a text index on the desired fields and using CommandDocument to run the text search, you can easily implement full-text search in your C# application.