CODE EXAMPLE FOR JAVASCRIPT

mongodb select all text not null

//This will return all documents with a key called "IMAGE URL", but they may still have a null value.
db.mycollection.find({"IMAGE URL":{$exists:true}});

//This will return all documents with both a key called "IMAGE URL" and a non-null value.
db.mycollection.find({"IMAGE URL":{$ne:null}});