How to compare two strings in mongoDB spring data?

问题

i'm trying to compare two string in mongoDB spring Data.
My Code:

@GET
     @Path("/reqvolatility")
     @Produces(MediaType.APPLICATION_JSON)

     public  long getReqVolatility() throws JsonParseException, JsonMappingException, IOException{

     String query = "{},{_id:0,levelId:1,reqID:1,creationTime:1,lastModified:1}";
     Query query1 = new BasicQuery(query); 
     query1.addCriteria(Criteria.where("creationTime").ne("lastModified"));
     long reqvolatility = getMongoOperation().count(query1,RequirmentVO.class);

     return reqvolatility;

    }

In the above code "creationTime" & "lastModified" columns in mongoDB.I'm comparing those two fields, but its not giving correct count. Is this correct? if it is wrong, How can i compare two fileds?

回答1:

Standard query operations do not compare the values of one field against another. In order to do this, you need to employ the JavaScript evaluation server side which can actually compare the two field values:

Assuming both fields are ISODate instances

 BasicQuery query = new BasicQuery(
        new BasicDBObject("$where", "this.creationTime.getTime() != this.lastModified.getTime()")
    );

来源：https://stackoverflow.com/questions/42838473/how-to-compare-two-strings-in-mongodb-spring-data