How to pass BasicDBList of $OR criteria to QueryBuilder? - mongodb

Question

My app is dynamically generating a mongo query via a QueryBuilder. I'm trying to make it so that the passed text can be compared against several fields in my collection. I need to iterate through data in order to know what to add to the $OR ( 'text_to_compare' vs title field, 'text_to_compare vs body field), so I've been trying to store each section of the $OR clause in a BasicDBList as follows:
BasicDBObject orsDBObject = new BasicDBObject();
BasicDBList orsList = new BasicDBList();
for( String dbFieldNameInstance: listDBFieldName ){
QueryBuilder innerQB = new QueryBuilder();
innerQB.put(dbFieldNameInstance).is(obj.getValue()); //using this inner QueryBuilder to assist in creating the document
orsList.add(innerQB.get());
}
orsDBObject.putAll(orsList); //put each of the BasicDBList items into a BasicDBObject
qb.or(orsDBObject); //finally, add the entire $OR clause to my bigger querybuilder
System.out.println("qb: " + qb.get());
It seems like I might be jumping through more conversions than are necessary. It isn't working either. The output from the above ends up looking like this:
qb: { "$or" : [ { "0" : { "primary_industries_names" : "electrical"} , "1" : { "primary_industries_aliases" : "electrical"} , "2" : { "secondary_industries_names" : "electrical"} , "3" : { "secondary_industries_aliases" : "electrical"} , "4" : { "product_experience_names" : "electrical"} , "5" : { "product_experience_aliases" : "electrical"}}]}
For the most part it looks right to me, however I don't think the "0": should be appearing in there. Any advice would be greatly appreciated.

Answer 1

You kind of have that the wrong way around. Not re-writing your code, but you should get the idea:
// Before the loop
QueryBuilder qb = new QueryBuilder();
// And loop things like this
for ( ) {
qb.or(new BasicDBObject("this","that"));
}
// After loop
System.out.println(qb.get());
If you are trying to nest several conditions then you seem to be missing the $and operator. Consider the following:
QueryBuilder qb = new QueryBuilder();
for (int x=0; x<2;x++) {
qb.or(new BasicDBObject("this","that"));
}
QueryBuilder qb2 = new QueryBuilder();
qb2.and(qb.get());
QueryBuilder qb3 = new QueryBuilder();
for (int x=0; x<2;x++) {
qb3.or(new BasicDBObject("something", "else"));
}
qb2.and(qb3.get());
System.out.println(qb2.get());