Using MongoDB C# Driver write ElementMatch with Regex query

Question

I need to construct the following query using MongoDB C# driver

db.Notes.find({ "Group._id" : 74, "CustomFields" : { "$elemMatch" : { "Value" : /batch/i } }, "IsDeleted" : false }).sort({ "CreatedDateTimeUtc" : -1 })

I used a query like this

builder.ElemMatch(x => x.CustomFields, x => x.Value.Contains(filterValue))

It generated mongo query as

db.Notes.find({ "Group._id" : 74, "CustomFields" : { "$elemMatch" : { "Value" : /batch/s } }, "IsDeleted" : false }).sort({ "CreatedDateTimeUtc" : -1 })

if you notice it is appending s at /batch/s instead of i /batch/i

How can I get this work? I need to do this for filters like

contains, using .Contains()
equals, thinking of using .Equals()
doesn't contain, thinking of using !Field.contains(value)
not equals to
starts with
ends with

Can I do something like this, so that I can apply all my regex patterns for all above filters.

builder.Regex(x => x.CustomFields[-1].Value, new BsonRegularExpression($"/{filterValue}/i"));

This converts the query to as below, but that doesn't get any results

db.Notes.find({ "Project._id" : 74, "CustomFields.$.Value" : /bat/i, "IsDeleted" : false }).sort({ "CreatedDateTimeUtc" : -1 })

FYI: builder is FilterDefinition<Note>

My sample Notes Collection is like this:

{  
   Name:"",
   Email:"",
   Tel:"",
   Date:02   /21/1945,
   CustomFields:[  
      {  
         Name:"",
         Value:"",
         IsSearchable:true,

      },
      {  
         Name:"",
         Value:"",
         IsSearchable:true,

      },
      {  
         Name:"",
         Value:"",
         IsSearchable:true,

      },
      {  
         Name:"",
         Value:"",
         IsSearchable:true,

      }
   ]
}

score 2 · Accepted Answer · answered Feb 19 '17 at 04:21

2

It sounds like all you're missing is the insensitive part. Have you tried this?

ToLower, ToLowerInvariant, ToUpper, ToUpperInvariant (string method) These methods are used to test whether a string field or property of the document matches a value in a case-insensitive manner.

According to the 1.1 documentation here, it says that will allow to perform a case insensitive regex match. The current documentation doesn't mention it, so just to be sure, i checked github and the code to create an insensitive match is still there.

answered Feb 19 '17 at 04:21

Taekahn

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insensitive part is one and I also need to write query where text begins with, text ends with and text doesn't contain. I think I can only do such things with BsonRegularexpression? – HaBo Feb 20 '17 at 09:20
Sorry, i missed that as part of the question. The mongo driver will correctly handle a `String.StartsWith()` and `String.EndsWith()`, turning them into `/^` and `$/` respectively. it should also turn a unary not `!` into a mongo `$not: { }` – Taekahn Feb 20 '17 at 17:01
how about "does not contain" search? – HaBo Feb 22 '17 at 18:54

Using MongoDB C# Driver write ElementMatch with Regex query

1 Answers1