How to concatenate fields using MongoDB Query language

Issue:

We need to concatenate two fields 'firstname' and 'lastname' into one field using Jaspersoft MongoDB Query language. 

How can this be achieved ?

Solution:

The following MongoDB Reference:

https://docs.mongodb.com/manual/reference/operator/aggregation/concat/index.html

has usages on how to perform a concatenation of string fields.

You can use the $concat operator within the aggregate operator. 

Example for TIBCO JasperReports Server version 7.5:

{
    collectionName : 'address',
    aggregate : [
        { $project : {  
             fullname : { $concat: [ "$firstname", " - ",  "$lastname"] } 
                         } 
           } 
    ]
 }

Related Articles:

https://community.jaspersoft.com/wiki/jaspersoft-mongodb-query-language