How do I connect to a database using a Simulink block created from a custom Matlab class?

I have created a Matlab class that needs to pull parameters from a database. The class has a function that makes a connection to the database and queries the appropriate data. It is called once, when the class is initialized. The class and connection works when I run it in the command window, however I would like the class to work as a block in a Simulink file.

Below is the code for the function. It was created with the help of the databaseExplorer. It uses commands from the database toolbox

function data = db_load_query(obj)
            % This queries the simAC01 database and returns the AC load parameters
            % corresponding to the simulation ID
            
            % Make connection to database
            conn = database('simAC01','******','*******'); % I stared out the actual credentials
            
            %Set query to execute on the database
            query = sprintf(['SELECT P, R, C, Rm, Cm, Tm, Tz ' ...
            'FROM simAC01.dbo.configs ' ...
            'WHERE id in (SELECT cfg_id ' ...
            'FROM simAC01.dbo.loads ' ...
            'WHERE sim_id = %d)'],obj.simID);

            % Execute query and fetch results
            data = fetch(conn,query);
            
            % Close connection to database
            close(conn)
            
            % Clear variables
            clear conn query
            
        end

When I try and run the class as a simulink block, I get this error:

I have tried running the block in interpreted mode but the error stayed pretty much the same.

I understand that the database function I am currently using can't be generated into code that is compatible with Simulink. I was wondering what functions should I be using or is there a way to make simulink work with the existing code.

Thanks for your time,

Peter

Answer 1

[Sayyed Ahmad]

Try to capsel your class in Matlab level2-s-function.

https://www.mathworks.com/help/simulink/slref/level2matlabsfunction.html

But think about it, if you use oop in level2-s-function you can use the block in simulink environment but you will not be able to compile this simulink block.

[Peter MacDonald]

Hey Sayyed Ahmad,

Thanks for the response. I woud prefer to be able to run the model both as a script and a simulink block if that is possible. Is that what you mean about not being able to compile this simulink block?

[Sayyed Ahmad]

I think it must work.

Matlab Compiler is not able to compile classes, which used in Level-2-S-Function to create machine code (Object Oriented Programming is not supported bei Matlab compiler for Level-2-S-Funtion).

If you are looking to create C or C++ code and put it on a chip, it is better to programming your S-Function as a not OOP matlab code. Otherwise it must work.