How to perform like on MongoDB document for integer values-CodePudding

At the moment, I currently have a "like" statement that works great for strings.

Builders<Book>.Filter.Regex("subject", new BsonRegularExpression(searchString.ToString(), "i"));

At the moment I'm trying to query the years and possibly search by 2 digit pattern such as 99, 98.

Some of the options I currently have in the documents are 2000, 1998, 1997, 1996.

If I query 98, the document with 1998 should be selected.

Unfortunately, the regex didn't work, wondering if I may get any tips or suggestions for integer number pattern with MongoDB C#.

CodePudding user response：

To work the regex with a numeric value, you need to cast it to a string first.

To do so, you need $regexMatch and $toString operators. As both operators are aggregation operators, you need to use $expr as well.

I think there is no supported feature/function for these operators in MongoDB .Net Driver, but you can provide the query as a BsonDocument.

filterDefinition &= new BsonDocument("$expr",
    new BsonDocument("$regexMatch",
        new BsonDocument
        {
            { "input", new BsonDocument("$toString", "$year") },
            { "regex", year },
            { "options", "i" }
        }
    )
);

So the filter query will be translated as below:

find({ "subject" : /(?:)/i, 
"$expr" : { "$regexMatch" : { "input" : { "$toString" : "$year" }, "regex" : "98", "options" : "i" } } })

Sample input data

Debugging & Output Result