Adding multiple records in a LightSwitch application

Question

I have been requested to add a new feature to my current LightSwitch application that is used to manage our employee training programme.  The problem revolves around the ability to create training needs for a multiple set of employees, instead of having
to create each training need individually.  The obvious benefit being reduced input for the team leaders, who have to create them for their respective teams.
The data schema looks like this:
I have tried to implement a Many to Many Relationship (Andy Kung) but it doesn't appear to meet the requirements.
The idea is to add some Local Properties for the team leader to Select the Course, and other required fields to capture the details of the training need.  Then to provide two data grids / lists, one which shows all employees reporting to the team
leader the other showing which employees have been selected for the training need. I'm thinking that this should be a list of employees that once the record is saved I'd execute some code to create new training needs for each of the selected employees. 
Am I going about this in the correct way for a LightSwitch application?  Any ideas would be appreciated.

Answer 1

It may be a problem of too many relationships. If it's a case where a Class can have multiple Employees, and an Employee can have multiple Classes, the easiest solution is to make a third table linking the two and use that table to manipulate the info.
Let's say the Class table has the following fields:
ID
ClassName
ClassLocation
ClassTime
ClassInstructor
and our Employee table has:
ID
EmployeeName
EmployeeDepartment
and whatever other fields you track on both, it doesn't really matter. These two tables should NOT have a relationship defined because many-to-many relationships aren't supported. (well, not directly, anyway.)
To create the Link table that solves the problem, simply create a new table in Lightswitch, but don't put any fields in it. (You can do that later, but working with the simplest version will show you how easy this is.)  Let's call it ClassStudentLink. 
ClassStudentLink only has one field, the auto-created Id field. Now, create a 1-to-many relationship to the Class table (which adds a collection of ClassStudentLinks to the Class table) and then another 1-to-many relationship to the Employee table (which
adds a collection of ClassStudentLinks to that one, too.)
Now you can create a Common Screen Set on this new link table.  When you go to the Add New ClassStudentLink screen, you get two modal pickers, once for Class, and one for Employee. Pick one of each, and save, and you just enrolled an Employee in your
Class.
From the Class table's View Class screens you can now add the child Link items which point to one Student each (i.e., click Add ClassStudentLinks on the data model on the left and drag it into a group on the screen. Do the same with the ClassStudentLink
table to add the linked Employee (because there will only be one for each link) and remove all the Link table fields from the screen but the Employee Name from the child (well, grandchild) record, because that's the only one you're interested in anyway.
You can do the exact same thing for the View Employee screen now, seeing which classes each selected Employee is enrolled in by adding the Link table there, too.
To show a Class roster, start with the Link table, change its Query filter to a selected Class, then display the EmployeeNames from the linked record.  To show a Class Transcript for an Employee, start with the Link table again, but set its Query
filter to a selected Employee.
What would really be nice is if you could set the Summary property of the Link table on the fly to point to a field in either of the related child tables, but I don't think it's possible.  Perhaps with pre-defined Queries in the data model, one going
each way, but I think you're limited to fields in the primary table only, not a child table.