mongodb - Case Insensitive search with $in

Question

How to search a column in a collection in mongodb with $in which includes an array of elements for search and also caseInsensitive matching of those elements in the column ?

Answer 1

Use $in with the match being case insensitive:

Data example:

{ 
    name : "...Event A",
    fieldX : "aAa" 
},
{ 
  name : "...Event B",
  fieldX : "Bab" 
},
{ 
  name : "...Event C",
  fieldX : "ccC" 
},
{ 
  name : "...Event D",
  fieldX : "dDd" 
}

And we want documents were "fieldX" is contained in any value of the array (optValues):

var optValues = ['aaa', 'bbb', 'ccc', 'ddd'];

var optRegexp = [];
optValues.forEach(function(opt){
        optRegexp.push(  new RegExp(opt, "i") );
});

db.collection.find( { fieldX: { $in: optRegexp } } );

This works for $all either.

I hope this helps!

p.s.: This was my solution to search by tags in a web application.