"parameter {0} must be a real scalar" error when using parfor

Hello,

In the following parfor loop, I want to add data into a newly created column in a mysql table by going row by row and manually inserting the data using the "update" function. But I end up getting an error, saying that the parameter isn't a scalar. I'm not sure why the error occurs since the beginning and ending values of the loop are both scalars. And if I replace "sizeOfColumn" with a literal constant, it also gives me the same error.

Thank You so much.

[Walter Roberson]

I wonder if you need to use

data = newColumn(i,1);

?

Answer 1

[Edric Ellis]

I think you need to use createConnectionForPool to make your database connection object and have it work correctly inside your parfor loop. (This was introduced in R2019a - if you're using an earlier release, you can probably achieve something pretty similar by using parallel.pool.Constant.)