Mongo DB : Implementing $not query - mongodb

Question

I am trying to implement following query from java code:
{ "Post Text" : { "$not" : /.*golf.*/i}}
my java code:
BasicDBObject not = new BasicDBObject();
not.append("$not", "/.*golf.*/i");
BasicDBObject query = new BasicDBObject();
query.put("Post Text", not);
When I am running above query, getting this log:
Cursor id=0, ns=journaldev.Rotunda, query={ "Post Text" : { "$not" : "/.golf./i" }}, numIterated=0, readPreference=primary
extra quotes around the regular expression are creating problem. Can someone help me in fixing this?

Answer 1

Using 3.x, you can use the Filters utility class to create various queries for you. In your case, you need the following construct:
Bson myFilter = Filters.not(
Filters.eq("Post Text",
Pattern.compile(".*golf.*", Pattern.CASE_INSENSITIVE)));
Using the 3.x driver to execute such a query is along the lines of:
MongoClient mongoClient = new MongoClient();
MongoCollection<Document> coll = mongoClient.getDatabase("test").getCollection("mycoll");
coll.find(myFilter); // do something with the FindIterable returned here

Answer 2

You can try something like this
Pattern textRegex = Pattern.compile(".*golf.*", Pattern.CASE_INSENSITIVE);
BasicDBObject not = new BasicDBObject("$not", textRegex);
BasicDBObject query = new BasicDBObject("Post Text", not);
When you pass a pattern, mongo driver automatically takes care of making it a regex. If you debug and see the code it will run with "$regex".
Hope this solves the problem