Mongodb查询以检查参数是否为真且不为null

Question

I am using Spring Boot to create an application. I have created a class for a Data access object which will retrieve data from MongoDB.

Query: The objective of the query is to check whether the parameter(boolean variable - control) is not null and true

I have tried the following query:

    Query query = new Query();
    query.addCriteria(new Criteria().andOperator(
    Criteria.where({"control":{$ne:null}}),
Criteria.where("control").is(true)));

However, it is incorrect. What should we use for checking whether a variable is not null - $exists or $ne?

Answer 1

You have to check null using if condition,

if(null != control) {
            query.addCriteria(Criteria.where("status").is(control));
}

Sample here