Get record from a table according to the associated array field in another table and generate a new collection made up of specific fields.
Here are two collections users and workouts. They are associated through array field users.WorkId and workouts._id.

The expected query result:

The MongoDB way of doing this is to join the two collections using $lookup, use unwind to split users.workouts table into records and lift them to the level of NAME, and then display the desired fields. The process is really a hassle.

esProc SPL handles this by preceding the name to the workouts records whose id field values are included in users.WorkId. That’s much easier.

Download esProc installation package HERE.
Directions to implement the esProc algorithm:

1. Write SPL script workout.dfx in esProc:

2. Execute the script and return the final result:

A4: A3.select() gets records of workouts whose _id values are included in users.WorkId and add the name field required in the result set to workouts.  

esProc provides JDBC interface, so you can easily integrate the script into a Java program:
public static void doWorkout() {
  Connection con = null;
  java.sql.Statement st;
 
  try{
    Class.forName("com.esproc.jdbc.InternalDriver");
    con = DriverManager.getConnection("jdbc:esproc:local://");
st=con.createStatement();
// Call script workout.dfx
ResultSet rst = st.executeQuery("call workout");
    System.out.println(rst);
   }catch(Exception e){
   System.out.println(e);
   }finally{
    // Close connection
    if (con!=null) {
      try {
       con.close();
     }catch(Exception e) {
        System.out.println(e);
      }
     }
   }
}