Negative regex filters

[Corina Ciulea]

Hi,

I am using MongoDB.Driver v2.0.1.27. Is there a way to do a negative regex query using MongoDB.Driver and FilterDefinition?

Thank you.

[Wan Bachtiar]

Hi Corina,

The $not operator does not support operations with the $regex operator. Although you can use the $not operator along with // to express a not filter match.

For example to find an item value that does not start with the word ‘baco’ in MongoDB Shell:

db.collection.find( { item: { $not: /^baco/ } } );

You can achieve a similar operation in C# using FilterDefinition, for example:

/* Create a regex filter for 'text' field not starting with 'friday'*/
FilterDefinition<BsonDocument> filter = "{text: {$not: /^friday/ }}";

var collectionFilter = collection.Find(filter);
var result = await collectionFilter.ToListAsync();
foreach (BsonDocument doc in result)
{ 
    Console.WriteLine(doc.ToString()); 
}

The example snippet above is written in:

• .Net framework v4.5.2
• MongoDB v3.0
• MongoDB C# driver v2.1.0

See Definitions and Builders for more information.

Regards,

Wan.

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